Getting Your Act Together: Cell Theory
Science Study Notes
Getting Your Act Together
Cell Theory
Cells are the basic structural and functional units of life. In multicellular organisms different cells perform different functions.
Different types of cells work together so that the organism functions as a co-ordinated whole
Unicellular and Multicellular Organisms
A multicellular organism is made up of many cells
A unicellular organism only has one cell
Plant Cell
Animal Cell
Basic Requirements Needed By Cells
Cells have 3 basic requirements: water, oxygen, nutrients (e.g. vitamins, minerals, amino acids)
Multicellular Animals “Systems” of Organs to Work Together
Levels of organisation – cells -> tissues -> organs -> systems -> organism …show more content…
Respiratory, circulatory, digestive, excretory, skeletal
Respiratory System
The process of obtaining energy from food and oxygen
Keeps all the cells alive
Food material that cells need for respiration is a sugar – glucose
Cells are supplied with oxygen by circulation of blood
Circulatory System
Components of blood – plasma, food, waste, chemicals, blood cells, cell parts
Digestive System
Digested food is used by the cells in bodies to provide energy, make new chemicals for the body and for energy storage
Food group before digestion
Food chemical after digestion starch glucose protein amino acids lipid glycerol
Excretory System excretory organs – kidney (makes urine), lungs (CO2, bring oxygen to blood), skin (salt, body heat), bladder (water)
Skeletal System
Bones support soft organs
Bones protect soft organs
Bones work with muscles to produce movement
In certain bones most blood cells are produced
Fats and minerals are stored in bones
Central nervous system – brain, spinal cord, control centre
Peripheral nervous system – sensory receptors and nerves
Neuron is single, nerves are neurons grouped together in bundles
Body Cells and Reproductive Cells
Meiosis – reproductive cells
2 daughter cells
Haploid
Different
Important for evolution
Mitosis – body cells
4 daughter cells
Diploid
Genetically same
Does not lead to evolution
Disease
A condition which the body or body parts do not function properly
Infectious and Non-Infectious Diseases
Infectious – e.g. measles, AIDs, chicken pox, malaria, influenza
Caused by pathogens, bacteria, viruses, fungi, protists, parasites
Non-Infectious – e.g. cancer, diabetes, anorexia, cystic fibrosis
Caused by factors, genetic, age, environment, lifestyle
Non-Infectious Disease Response
White blood cells travel to the blood to the infection site and eat pathogens
Vaccination
Two types of immunity produced by vaccines – active immunity, passive immunity
Active immunity: body stimulated to make its own antibodies, injecting live but disabled version of the virus/ bacteria
Passive immunity: body injected with antibodies previously made by another organism, good in emergency situations when immunity is needed quickly, does not last as long as active immunity
Infectious Disease Response
Creates a barrier
Tries to detect and eliminate it before it can reproduce
Immune system is in charge of eliminating it e.g. skin, filtered air, body fluids, acid, acidic mucus, inflammation, pus, lymphatic system
Co-ordination Systems
Endocrine System – hormones are released into the blood, glands release chemical messengers (hormones) into the
Nervous System –
Nervous System and Functions
Cerebrum – memory, learning, processes info from senses, controls thought, voluntary movement
Cerebellum – controls balance, muscular co-ordinance
Medulla –controls breathing, heartbeat, other vital body processes
Spinal cord – relays impulses between the brain and other vital body parts
Spinal nerves – carry impulses between spinal cord and body parts
Brain - sensory motor, controls the functioning of the body
Nerve Cell and Synapse
Reflex and Voluntary Action
Reflex Action – actions that need to be carried out automatically and without thinking usually require only a few neurons, very fast, e.g. blinking, coughing, sneezing
Voluntary Action – produced by conscious choice, would be aware of the action while executed
Endocrine System
Made up of glands that produce hormones
Hormones regulate the body's growth, metabolism, sexual development and function, storage and release of glucose into the blood
Major glands - hypothalamus, pituitary gland, thyroid, parathyroids, adrenal glands, pineal body, reproductive organs
A gland selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body
Pituitary gland - makes hormones that control several other endocrine glands
Hypothalamus - producing chemicals that stimulate/suppress hormone secretions from the pituitary
Thyroid - control the rate at which cells burn fuels from food to produce energy
Parathyroids - regulates the level of calcium in the blood
Adrenal glands – (Outer) influence or regulate salt and water balance in the body, the body's response to stress, metabolism, the immune system, and sexual development and function. (Inner) increases blood pressure and heart rate when the body experiences stress.
Pineal - help regulate when you sleep at night and when you wake in the morning
Reproductive organs – puberty
Periodic Table
Atoms and Molecules
Atom smallest unit of matter
One atom is equal to a single particle of matter, made up of positively charged protons, neutral neutrons which together make up the centre of atom, the nucleus which is orbited by the negatively charged electrons in their shells
Molecule made up of two or more atoms combine throughout chemical bonds
Location & Features of Protons, Neutrons, Electrons
Protons are found in the nucleus – positive charge
Neutrons are found in the nucleus – neutral charge
Electrons orbit the nucleus – negative charge
Elements
The number of electrons is the same as the number or protons
Electrons fill the lowest shell first
The number of shells used by an atom is the same as the period number
The group number is the same as the number of outer shell electrons
Protons and electrons is the same as the atomic number
Neutrons is subtracting protons from the atomic mass
Atomic Number & Atomic Mass
Atomic mass – is equal to the mass of the protons + mass of neutrons in the nucleus. The nucleus is rounded off to the nearest whole number to determine numbers of protons and neutrons
Atomic number – is equal to the number of protons in each element
Structure of an Atom ^
Only 2 electrons fill the first shell, closest to the nucleus
8 electrons fill the second shell
8 electrons fill the third shell
Arrangement of Electrons
2:8:8
History of Atomic Theory
1808 – Dalton
1897 – Thomson
1908 – Rutherford
1913 – Bohr
Models of an Atom
Benefits – should explain all observations, can be used to make predictions, simplify
Deficits – simplify/ generalise, doesn’t give all the information
KEY
Atomic number Symbol of element Atomic weight Name of element
Groups on Periodic Table
Group I – the alkali metals
Group II – the alkaline earths
Group IV – the titaniums
Group VII – the halogens
Group VIII – the noble gases
HOW TO READ PERIODIC TABLE??
Acids and Bases
Distinguish Between Elements and Compounds
Element – substance made up of only one type of element
Compound – two or more different elements bonded together
Distinguish Between Compounds and Mixtures
Compound – two or more different elements bonded together
Mixture – two or more substances mixed together. NOT BONDED together. Can be easily separated
How New Compound is formed by Rearranging Atoms
Law of Conservation of Mass
In any chemical reaction the mass of things produced will be the same like the reactant it used
Mass of things reacted = mass of things produced
Atoms Combining by Gaining/Losing/Sharing Electrons
Atoms usually combine with other atoms, of the same or different elemental type, into different forms of matter
An atom moves in three ways: translational, rotational, and vibrational
Non-metal atoms combine, by sharing electrons, into molecules, building blocks of many kinds of matter.
Metals and non-metals combine, gaining or losing electrons, they form solids called ionic crystals
Characteristics That Classify Substances: Ionic/Covalent Substances
If a compound is made from a metal and a non-metal, its bonding will be ionic
If a compound is made from two non-metals, its bonding will be covalent
Common Compounds
Note that: Acid + Base → Salt + Water. The formula for water is H2O
Grouping Compounds Based on Common Chemical Characteristics
Characteristics of Acids, Bases and Salts
Salts – Salt is a compound (acid and a base combined), formed when an acid reacts with a base, combines with a metal or carbonate to form a compound, e.g. acid + base = salt + water
Bases – pH range >7, can be used to neutralise an acid, can form OH – ions in solutions
Acids – pH range Salt + Hydrogen: e.g. Hydrochloric Acid + Magnesium -> Magnesium Chloride and Hydrogen
Acids on Carbonates -> Salt + Water + Carbon Dioxide: e.g. Hydrochloric Acid + Sodium Carbonate -> Sodium Carbonate + Water
Neutralisation -> a reaction where an acid and a base react (in an aqueous solution) to produce salt and water
Indicators
A substance that changes colour in acidic and basic solutions
Lets you determine the equivalence end point that's only when the reaction takes place
Lucas Heights
Isotopes – isotopes of an element are different forms of the same element. Isotopes have the same number of protons and electrons, but different numbers of neutrons. E.g. Hydrogen occurs as three different isotopes
Nuclear radiation – Alpha particles, Beta particles, gamma rays
Electromagnetic radiation – gamma rays, x-rays, UV rays
Radiation made by the decay of radioactive atoms – gamma rays, beta rays, alpha rays
Geiger – Muller Tube – each particle of radiation produces a tiny pulse of electricity. This is detected and amplified.
Name
Ability to penetrate
Particle or wavelength
Alpha
Low
Particle
Beta
Medium
Particle
Gamma
Very high
Electromagnetic wave
Nuclear radiation consists of high speed particles
Decay of radioactive atoms in the soil, air and food
When radiation is in our bodies it can alter or destroy the molecules in the cells
Radiation can kill or save humans
Good
Bad
Treat cancer
Damage gastrointestinal tact
Diagnose disease
Wound living tissues
Prevent disease
Death
x-ray machine
Damage nervous system
Energy production
Food sterilisation
Our bodies have up to 20 billion radioactive atoms, potassium – 40, carbon – 14, hydrogen –3
Sievert is used to measure the effect of radiation in living tissue
A single dose of 1 000 000 to 1 500 000 usv (microsiervert) can give you radiation sickness
5 000 000 to 6 000 000 can kill you
Electromagnetic radiation – varying electric magnetic fields.
Travels through space at very high speed, 30 000 km/s. Wave, sometimes stream of particles.
Wavelength- the distance between adjacent crests of the wave
Frequency- of a wave is the number of waves passing a fixed point per second. Measured in hertz
Amplitude – of a wave is the distance from the middle of the wave to the top
Each type of EM has a different wavelength and carries a different amount of energy
Short wavelength carry more energy than longer wavelengths
EM waves can travel through a vacuum, they are transverse waves. The electric and magnetic forces are at right angles the direction of motion of the wave
Cosmic rays – high speed charged particles. Originate from outer space. Form part of the natural radiation that surrounds us most of the …show more content…
time
Gamma rays – originate from the nuclei of some atoms. Very penetrating and can cause death of living things in large doses. Can be detected by a Geiger counter, photographic film or ionisation chamber
X-rays – produced by causing electrons to strike the heavy
Human Impact
Biotic & Abiotic
Biotic – living things e.g. plants, animals, bacteria, and fungi
Abiotic – non-living e.g. oxygen, water, nitrogen, ultraviolet rays
Importance of Energy
If there was no "energy" resource - there would be no sun - the main source of our energy
Renewable and Non-renewable Resources
Renewable – when something can be reused e.g. wind, solar, tidal & wave, biomass, hydroelectric, geothermal energy
Non-Renewable – cannot be reused e.g. coal, gas, nuclear energy, petroleum
Importance of Developing Renewable Sources of Energy
Protect our environment and public health by avoiding or reducing emissions that contribute to smog, acid rain, and global warming; and by reducing water consumption, thermal pollution, waste, noise, and adverse land use
Increase economic development and create new family-wage jobs
Create new competition to help restrain fossil fuel price increases
Improve our national security
Diversify our fuel mix and enhance the reliability of fuel supplies
Insulate our economy from fossil fuel price spikes and supply shortages or disruptions
Reduce a growing reliance on imported fuel and electricity
Reduce the cost of complying with present and future environmental regulations
Conserve our natural resources for future generations
Importance of Cycles (carbon cycle)
CO2 trap heat in the atmosphere—one of the basic mechanisms behind the greenhouse effect, which raises temperatures near the earth’s surface
Life-sustaining element, from the atmosphere and oceans into organisms and back again to the atmosphere and oceans. If the balance between these latter two reservoirs is upset, serious consequences, such as global warming and climate disruption, may result
Keeps ecosystem balanced
Properties That Make Natural Resources Economically Important
Sunlight is economically important because it not only has many uses, but can be found everywhere across the Earth
What they are worth, their location, how accessible they are, their uses (many or few)
*COLUMN GRAPHS, HISTOGRAMS, DIVDED BAR AND SECTOR GRAPHS, LINE GRAPHS, COMPOSITE GRAPHS AND FLOW DIAGRAMS
Impacts of Human Activities on an Ecosystem
Air and water pollution leading to ozone hole, greenhouse effect, acid rain and bioaccumulation
Excessive Use of Fossil Fuels
CO2 released into atmosphere causes temperature in atmosphere to rise, increase in temperature makes hole in ozone layer increase. Rainfall patterns will be affected and natural disasters like drought, flood, heat waves, high winds and cyclones may occur more frequently
Recycling (e.g. aluminium)
The consumer throws aluminium cans and foil into a recycle bin.
The aluminium is then collected and taken to a treatment plant.
In the treatment plant the aluminium is sorted and cleaned ready for reprocessing.
It then goes through a re-melt process and turns into molten aluminium, this removes the coatings and inks that may be present on the aluminium.
The aluminium is then made into large blocks called ingots. Each ingot contains about 1.6 million drinks cans.
The ingots are sent to mills where they are rolled out, this gives the aluminium greater flexibility and strength.
This is then made into aluminium products such as cans, chocolate wrapping and ready meal packaging. In as little as 6 weeks, the recycled aluminium products are then sent back to the shops ready to be used again
El Nino & La Nina
El Niño part of the cycle involves warmer-than-usual sea temperatures, great amounts of rainfall (in the northern hemisphere) and low atmospheric pressure Cooler sea temperatures, high atmospheric pressure and drier air characterize the La Niña phase of the Southern Oscillation
Increased intensity and frequency—now every two to three years—of El Niño and La Niña events in recent decades is due to warmer ocean temperatures resulting from global warming.
Higher global temperatures might be increasing evaporation from land and adding moisture to the air, thus intensifying the storms and floods associated with El Niño
Southern Oscillation may be functioning like a pressure release valve for the tropics. With global warming driving temperatures higher, ocean currents and weather systems might not be able to release all the extra heat getting pumped into the tropical seas; as such an El Niño occurs to help expel the excess heat
Environmental Problems Caused by Mining
Erosion, formation of sinkholes, loss of biodiversity, especially marine life, and contamination of water bodies
Soil erosion is prominent as mines are reclaimed when they are closed down. This will cause instability in the soil, which is prone to erosion when there is a heavy rain. Soil and other minerals from the mine also run into water bodies, contaminating them and destroying marine life
Biodegradable and Non-biodegradable Waste
Biodegradable wastes decompose into soil e.g. human & animal waste
Non-biodegradable wastes take a long time or never to decompose e.g. metal cans
Pollution is Contamination by Unwanted Substance
Contamination of air, water, or soil
By-products of industries
Waste from animals, pesticides and herbicides are washed into rivers and then into the sea
Homes and offices produce rubbish
Waste from animals, pesticides and herbicides are washed into rivers and then into the sea
Effects of Pollution
Air pollution can cause breathing problems and eye, throat and skin irritation. When solid waste is not properly treated and disposed of, it can become a breeding for pests and disease can spread
Leaves find it difficult to manufacture food in polluted air. When trees begin to lose their leaves, they may eventually die. When there is too much chemical content in the water absorbed by the roots, it can also affect plant life
Oil spills in the seas and oceans result in birds and animals (e.g. penguins and seals) being coated in oil. This makes it difficult for them to float and keep warm and they may eventually die. Solid waste in the water -> growth of algae which depletes water of oxygen and kills marine life
Air pollution discolours and corrodes buildings and statues
Different Strategies to Solve Pollution
Reduce, reuse, recycle
Grow your own food, eat locally, redecorate with eco-products, buy energy-efficient appliances with ‘energy star’ label, reduce your heating, reduce your electricity use, try alternative energy devices, buy durable goods, install a hot water heat recycling unit to reduce electricity/fuel burned for domestic heating, pack your refrigerator more tightly to reduce cooled air, reduce usage of refrigerator and air-conditioners, use a reel lawnmower, walk/public transport
Investigations
Types of Questions Answered Using Scientific Method
Physical sciences, where it is possible to observe natural phenomena of various kinds and to make hypotheses about how systems work
Steps in Scientific Method
Aim (question you are trying to answer)
Hypothesis (relate dependent/independent variables, what you think will happen)
Equipment (be precise inc. measurements)
Method (past tense, starts with verb, impersonal, steps, concise & precise)
Results (table/graph)
Conclusion (relates directly back to the hypothesis, 1-2 sentences, e.g. …was proven/not proven)
Discussion (what went wrong, how could the experiment be improved, other experiments that might be done)
Senses - taste, touch, smell, see, and hear
Inference - form an opinion by reasoning
Generalisation - make a statement that is true of most cases
Hypothesis – a suggestion or guess that tries to explain something
Repeating or pooling measurements and averaging
COWS - change (I – independent)
MOO – measure (DON’T – dependent)
SOFTLY - same (CARE – control)
SAFELY – risk assessment, look for dangers
REPEATEDLY – repeat x5
Dynamic Earth
Crust – makes up part of the lithosphere, thinnest layer 8-50km
Mantle – thickest 3000km, liquid
Core – outer core 2000km thick, molten nickel & iron. Inner core 1400km thick, solid nickel & iron
Asthenosphere – the upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection, is thought to occur
Lithosphere – the hot outer part of the earth consisting of the crust and upper mantle
Biosphere – the regions of the surface, atmosphere, and hydrosphere of the earth occupied by living organisms
Hydrosphere – all the waters on the earth’s surface, such as lakes and seas, and sometimes including water over the earth’s surface, such as clouds
Atmosphere – the envelope if gases surrounding the earth or another planet
Theory – a supposition or a system of ideas intended to explain something
Law – the system of rules that a particular country or community recognises as regulating the actions of its members
Fossil Formation
A leaf falls from a tree and settles in the mud at the bottom of the swamp
Layers of mud and dirt settle over the leaf and bury it
The mud compacts together and forms rock
The rock is pushed up by forces from within the earth and is then eroded
Fossil leaves in the form of coal can be exposed in a hillside
Plate Tectonics
Earth's outer layer is made up of plates, which have moved throughout Earth's history
Godwana & Laurasia
The rigid slabs of lithosphere
Convection Currents
Hot air and liquids rise and so does hot molten rock.
Likewise ’cool’ rock drops, heat from deep within the earth causes the molten rock of the mantle to move upwards. When this hot mantle rock comes into with the relatively cold crust it cools and sinks. Convection currents in the mantle are the result
Interactions at Plate Boundaries
Spreading boundaries – plates move apart, aka constructive boundaries, rock being formed
Collision boundaries – one plate collides with another, aka destructive boundaries, rock melted and returned to the mantle for recycling
Transform or scraping boundaries – plates scrape along each other, aka conservative boundaries, conserve rock (does not create/break)
The rock oceanic plates are denser than the plates that the continents sit on. When they hit, the heavier the oceanic plate is forced under the continental plate at an angle of 20o to 60o to the surface. This angle dive is called a subduction zone
When two continental plates collide, the crumple and fold – mountain formed
Plates that scrape along each other along a transform boundary – earthquake
formed
Tectonic plate sinks into the mantle, becomes very hot, rock melts, molten rock gradually make its way up to surface of earth through a series of cracks. As layer upon layer of lava builds up, a volcano is formed
Sedimentary, Metamorphic, Igneous
Sedimentary – formed from particles that have settled on a surface. Found in where there used to be oceans and seas or other bodies of water (e.g. gravel, coal, sand, shale)
Metamorphic – formed or changed by heat or pressure. Found in deep underground, at the base of mountains, in zones radiating from intrusions of magma underground, on glaciated terrain after transportation by ice, or on the surface of eroded mountains (e.g. marble, sand, slate)
Igneous – formed by the action of a volcano. Found in the surface in areas of current or past volcanism or in uplifted and eroded areas of past plutonic intrusions, deep underground nearly anywhere, or in areas of past or present glaciation, where igneous rock has been eroded and deposited (e.g. sand, granite, gneiss)
ACDC
An energy source, such as a battery
A conductor (wires) for the electricity to flow through
Something to use up the electrical energy such as a globe or a motor
A switch to turn on and off the current
Current – a flow of electricity which results from the ordered directional movement of electricity charged particles
Voltage – a measure of the amount of energy available to push charges around a circuit
Chemicals inside a cell cause chemical reactions which generate free electrons which constitute the current
Conductor – a substance that allows current to flow through it easily. Metals are good conductors of electricity
Insulator – materials that do not normally allow current to pass through them. Plastic and rubber are very effective insulators
The resistance – part of a circuit that causes electrons to lose most of their energy
AC – alternating current (an electrical generator makes and supplies electricity) backwards and forwards
DC – direct current (electromagnetic induction is the production of voltage across a conductor moving through a magnetic field) one direction
CRO – oscilloscope (a voltmeter with a screen. The vertical movement of the light on the screen shows the size of the voltage)
Hz – Hertz
Ohm’s Law (V=IR) Volts (V) = Amps (I) x Ohms (R)
As voltage across a resistor increases, current increases proportionally
If voltage across a resistor remains constant, increasing the value of the resistor decreases the current flowing through it by the same position (i.e. double resistors, ½ current)
Getting Your Act Together
Cell Theory
Cells are the basic structural and functional units of life. In multicellular organisms different cells perform different functions.
Different types of cells work together so that the organism functions as a co-ordinated whole
Unicellular and Multicellular Organisms
A multicellular organism is made up of many cells
A unicellular organism only has one cell
Plant Cell
Animal Cell
Basic Requirements Needed By Cells
Cells have 3 basic requirements: water, oxygen, nutrients (e.g. vitamins, minerals, amino acids)
Multicellular Animals “Systems” of Organs to Work Together
Levels of organisation – cells -> tissues -> organs -> systems -> organism …show more content…
Respiratory, circulatory, digestive, excretory, skeletal
Respiratory System
The process of obtaining energy from food and oxygen
Keeps all the cells alive
Food material that cells need for respiration is a sugar – glucose
Cells are supplied with oxygen by circulation of blood
Circulatory System
Components of blood – plasma, food, waste, chemicals, blood cells, cell parts
Digestive System
Digested food is used by the cells in bodies to provide energy, make new chemicals for the body and for energy storage
Food group before digestion
Food chemical after digestion starch glucose protein amino acids lipid glycerol
Excretory System excretory organs – kidney (makes urine), lungs (CO2, bring oxygen to blood), skin (salt, body heat), bladder (water)
Skeletal System
Bones support soft organs
Bones protect soft organs
Bones work with muscles to produce movement
In certain bones most blood cells are produced
Fats and minerals are stored in bones
Central nervous system – brain, spinal cord, control centre
Peripheral nervous system – sensory receptors and nerves
Neuron is single, nerves are neurons grouped together in bundles
Body Cells and Reproductive Cells
Meiosis – reproductive cells
2 daughter cells
Haploid
Different
Important for evolution
Mitosis – body cells
4 daughter cells
Diploid
Genetically same
Does not lead to evolution
Disease
A condition which the body or body parts do not function properly
Infectious and Non-Infectious Diseases
Infectious – e.g. measles, AIDs, chicken pox, malaria, influenza
Caused by pathogens, bacteria, viruses, fungi, protists, parasites
Non-Infectious – e.g. cancer, diabetes, anorexia, cystic fibrosis
Caused by factors, genetic, age, environment, lifestyle
Non-Infectious Disease Response
White blood cells travel to the blood to the infection site and eat pathogens
Vaccination
Two types of immunity produced by vaccines – active immunity, passive immunity
Active immunity: body stimulated to make its own antibodies, injecting live but disabled version of the virus/ bacteria
Passive immunity: body injected with antibodies previously made by another organism, good in emergency situations when immunity is needed quickly, does not last as long as active immunity
Infectious Disease Response
Creates a barrier
Tries to detect and eliminate it before it can reproduce
Immune system is in charge of eliminating it e.g. skin, filtered air, body fluids, acid, acidic mucus, inflammation, pus, lymphatic system
Co-ordination Systems
Endocrine System – hormones are released into the blood, glands release chemical messengers (hormones) into the
Nervous System –
Nervous System and Functions
Cerebrum – memory, learning, processes info from senses, controls thought, voluntary movement
Cerebellum – controls balance, muscular co-ordinance
Medulla –controls breathing, heartbeat, other vital body processes
Spinal cord – relays impulses between the brain and other vital body parts
Spinal nerves – carry impulses between spinal cord and body parts
Brain - sensory motor, controls the functioning of the body
Nerve Cell and Synapse
Reflex and Voluntary Action
Reflex Action – actions that need to be carried out automatically and without thinking usually require only a few neurons, very fast, e.g. blinking, coughing, sneezing
Voluntary Action – produced by conscious choice, would be aware of the action while executed
Endocrine System
Made up of glands that produce hormones
Hormones regulate the body's growth, metabolism, sexual development and function, storage and release of glucose into the blood
Major glands - hypothalamus, pituitary gland, thyroid, parathyroids, adrenal glands, pineal body, reproductive organs
A gland selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body
Pituitary gland - makes hormones that control several other endocrine glands
Hypothalamus - producing chemicals that stimulate/suppress hormone secretions from the pituitary
Thyroid - control the rate at which cells burn fuels from food to produce energy
Parathyroids - regulates the level of calcium in the blood
Adrenal glands – (Outer) influence or regulate salt and water balance in the body, the body's response to stress, metabolism, the immune system, and sexual development and function. (Inner) increases blood pressure and heart rate when the body experiences stress.
Pineal - help regulate when you sleep at night and when you wake in the morning
Reproductive organs – puberty
Periodic Table
Atoms and Molecules
Atom smallest unit of matter
One atom is equal to a single particle of matter, made up of positively charged protons, neutral neutrons which together make up the centre of atom, the nucleus which is orbited by the negatively charged electrons in their shells
Molecule made up of two or more atoms combine throughout chemical bonds
Location & Features of Protons, Neutrons, Electrons
Protons are found in the nucleus – positive charge
Neutrons are found in the nucleus – neutral charge
Electrons orbit the nucleus – negative charge
Elements
The number of electrons is the same as the number or protons
Electrons fill the lowest shell first
The number of shells used by an atom is the same as the period number
The group number is the same as the number of outer shell electrons
Protons and electrons is the same as the atomic number
Neutrons is subtracting protons from the atomic mass
Atomic Number & Atomic Mass
Atomic mass – is equal to the mass of the protons + mass of neutrons in the nucleus. The nucleus is rounded off to the nearest whole number to determine numbers of protons and neutrons
Atomic number – is equal to the number of protons in each element
Structure of an Atom ^
Only 2 electrons fill the first shell, closest to the nucleus
8 electrons fill the second shell
8 electrons fill the third shell
Arrangement of Electrons
2:8:8
History of Atomic Theory
1808 – Dalton
1897 – Thomson
1908 – Rutherford
1913 – Bohr
Models of an Atom
Benefits – should explain all observations, can be used to make predictions, simplify
Deficits – simplify/ generalise, doesn’t give all the information
KEY
Atomic number Symbol of element Atomic weight Name of element
Groups on Periodic Table
Group I – the alkali metals
Group II – the alkaline earths
Group IV – the titaniums
Group VII – the halogens
Group VIII – the noble gases
HOW TO READ PERIODIC TABLE??
Acids and Bases
Distinguish Between Elements and Compounds
Element – substance made up of only one type of element
Compound – two or more different elements bonded together
Distinguish Between Compounds and Mixtures
Compound – two or more different elements bonded together
Mixture – two or more substances mixed together. NOT BONDED together. Can be easily separated
How New Compound is formed by Rearranging Atoms
Law of Conservation of Mass
In any chemical reaction the mass of things produced will be the same like the reactant it used
Mass of things reacted = mass of things produced
Atoms Combining by Gaining/Losing/Sharing Electrons
Atoms usually combine with other atoms, of the same or different elemental type, into different forms of matter
An atom moves in three ways: translational, rotational, and vibrational
Non-metal atoms combine, by sharing electrons, into molecules, building blocks of many kinds of matter.
Metals and non-metals combine, gaining or losing electrons, they form solids called ionic crystals
Characteristics That Classify Substances: Ionic/Covalent Substances
If a compound is made from a metal and a non-metal, its bonding will be ionic
If a compound is made from two non-metals, its bonding will be covalent
Common Compounds
Note that: Acid + Base → Salt + Water. The formula for water is H2O
Grouping Compounds Based on Common Chemical Characteristics
Characteristics of Acids, Bases and Salts
Salts – Salt is a compound (acid and a base combined), formed when an acid reacts with a base, combines with a metal or carbonate to form a compound, e.g. acid + base = salt + water
Bases – pH range >7, can be used to neutralise an acid, can form OH – ions in solutions
Acids – pH range Salt + Hydrogen: e.g. Hydrochloric Acid + Magnesium -> Magnesium Chloride and Hydrogen
Acids on Carbonates -> Salt + Water + Carbon Dioxide: e.g. Hydrochloric Acid + Sodium Carbonate -> Sodium Carbonate + Water
Neutralisation -> a reaction where an acid and a base react (in an aqueous solution) to produce salt and water
Indicators
A substance that changes colour in acidic and basic solutions
Lets you determine the equivalence end point that's only when the reaction takes place
Lucas Heights
Isotopes – isotopes of an element are different forms of the same element. Isotopes have the same number of protons and electrons, but different numbers of neutrons. E.g. Hydrogen occurs as three different isotopes
Nuclear radiation – Alpha particles, Beta particles, gamma rays
Electromagnetic radiation – gamma rays, x-rays, UV rays
Radiation made by the decay of radioactive atoms – gamma rays, beta rays, alpha rays
Geiger – Muller Tube – each particle of radiation produces a tiny pulse of electricity. This is detected and amplified.
Name
Ability to penetrate
Particle or wavelength
Alpha
Low
Particle
Beta
Medium
Particle
Gamma
Very high
Electromagnetic wave
Nuclear radiation consists of high speed particles
Decay of radioactive atoms in the soil, air and food
When radiation is in our bodies it can alter or destroy the molecules in the cells
Radiation can kill or save humans
Good
Bad
Treat cancer
Damage gastrointestinal tact
Diagnose disease
Wound living tissues
Prevent disease
Death
x-ray machine
Damage nervous system
Energy production
Food sterilisation
Our bodies have up to 20 billion radioactive atoms, potassium – 40, carbon – 14, hydrogen –3
Sievert is used to measure the effect of radiation in living tissue
A single dose of 1 000 000 to 1 500 000 usv (microsiervert) can give you radiation sickness
5 000 000 to 6 000 000 can kill you
Electromagnetic radiation – varying electric magnetic fields.
Travels through space at very high speed, 30 000 km/s. Wave, sometimes stream of particles.
Wavelength- the distance between adjacent crests of the wave
Frequency- of a wave is the number of waves passing a fixed point per second. Measured in hertz
Amplitude – of a wave is the distance from the middle of the wave to the top
Each type of EM has a different wavelength and carries a different amount of energy
Short wavelength carry more energy than longer wavelengths
EM waves can travel through a vacuum, they are transverse waves. The electric and magnetic forces are at right angles the direction of motion of the wave
Cosmic rays – high speed charged particles. Originate from outer space. Form part of the natural radiation that surrounds us most of the …show more content…
time
Gamma rays – originate from the nuclei of some atoms. Very penetrating and can cause death of living things in large doses. Can be detected by a Geiger counter, photographic film or ionisation chamber
X-rays – produced by causing electrons to strike the heavy
Human Impact
Biotic & Abiotic
Biotic – living things e.g. plants, animals, bacteria, and fungi
Abiotic – non-living e.g. oxygen, water, nitrogen, ultraviolet rays
Importance of Energy
If there was no "energy" resource - there would be no sun - the main source of our energy
Renewable and Non-renewable Resources
Renewable – when something can be reused e.g. wind, solar, tidal & wave, biomass, hydroelectric, geothermal energy
Non-Renewable – cannot be reused e.g. coal, gas, nuclear energy, petroleum
Importance of Developing Renewable Sources of Energy
Protect our environment and public health by avoiding or reducing emissions that contribute to smog, acid rain, and global warming; and by reducing water consumption, thermal pollution, waste, noise, and adverse land use
Increase economic development and create new family-wage jobs
Create new competition to help restrain fossil fuel price increases
Improve our national security
Diversify our fuel mix and enhance the reliability of fuel supplies
Insulate our economy from fossil fuel price spikes and supply shortages or disruptions
Reduce a growing reliance on imported fuel and electricity
Reduce the cost of complying with present and future environmental regulations
Conserve our natural resources for future generations
Importance of Cycles (carbon cycle)
CO2 trap heat in the atmosphere—one of the basic mechanisms behind the greenhouse effect, which raises temperatures near the earth’s surface
Life-sustaining element, from the atmosphere and oceans into organisms and back again to the atmosphere and oceans. If the balance between these latter two reservoirs is upset, serious consequences, such as global warming and climate disruption, may result
Keeps ecosystem balanced
Properties That Make Natural Resources Economically Important
Sunlight is economically important because it not only has many uses, but can be found everywhere across the Earth
What they are worth, their location, how accessible they are, their uses (many or few)
*COLUMN GRAPHS, HISTOGRAMS, DIVDED BAR AND SECTOR GRAPHS, LINE GRAPHS, COMPOSITE GRAPHS AND FLOW DIAGRAMS
Impacts of Human Activities on an Ecosystem
Air and water pollution leading to ozone hole, greenhouse effect, acid rain and bioaccumulation
Excessive Use of Fossil Fuels
CO2 released into atmosphere causes temperature in atmosphere to rise, increase in temperature makes hole in ozone layer increase. Rainfall patterns will be affected and natural disasters like drought, flood, heat waves, high winds and cyclones may occur more frequently
Recycling (e.g. aluminium)
The consumer throws aluminium cans and foil into a recycle bin.
The aluminium is then collected and taken to a treatment plant.
In the treatment plant the aluminium is sorted and cleaned ready for reprocessing.
It then goes through a re-melt process and turns into molten aluminium, this removes the coatings and inks that may be present on the aluminium.
The aluminium is then made into large blocks called ingots. Each ingot contains about 1.6 million drinks cans.
The ingots are sent to mills where they are rolled out, this gives the aluminium greater flexibility and strength.
This is then made into aluminium products such as cans, chocolate wrapping and ready meal packaging. In as little as 6 weeks, the recycled aluminium products are then sent back to the shops ready to be used again
El Nino & La Nina
El Niño part of the cycle involves warmer-than-usual sea temperatures, great amounts of rainfall (in the northern hemisphere) and low atmospheric pressure Cooler sea temperatures, high atmospheric pressure and drier air characterize the La Niña phase of the Southern Oscillation
Increased intensity and frequency—now every two to three years—of El Niño and La Niña events in recent decades is due to warmer ocean temperatures resulting from global warming.
Higher global temperatures might be increasing evaporation from land and adding moisture to the air, thus intensifying the storms and floods associated with El Niño
Southern Oscillation may be functioning like a pressure release valve for the tropics. With global warming driving temperatures higher, ocean currents and weather systems might not be able to release all the extra heat getting pumped into the tropical seas; as such an El Niño occurs to help expel the excess heat
Environmental Problems Caused by Mining
Erosion, formation of sinkholes, loss of biodiversity, especially marine life, and contamination of water bodies
Soil erosion is prominent as mines are reclaimed when they are closed down. This will cause instability in the soil, which is prone to erosion when there is a heavy rain. Soil and other minerals from the mine also run into water bodies, contaminating them and destroying marine life
Biodegradable and Non-biodegradable Waste
Biodegradable wastes decompose into soil e.g. human & animal waste
Non-biodegradable wastes take a long time or never to decompose e.g. metal cans
Pollution is Contamination by Unwanted Substance
Contamination of air, water, or soil
By-products of industries
Waste from animals, pesticides and herbicides are washed into rivers and then into the sea
Homes and offices produce rubbish
Waste from animals, pesticides and herbicides are washed into rivers and then into the sea
Effects of Pollution
Air pollution can cause breathing problems and eye, throat and skin irritation. When solid waste is not properly treated and disposed of, it can become a breeding for pests and disease can spread
Leaves find it difficult to manufacture food in polluted air. When trees begin to lose their leaves, they may eventually die. When there is too much chemical content in the water absorbed by the roots, it can also affect plant life
Oil spills in the seas and oceans result in birds and animals (e.g. penguins and seals) being coated in oil. This makes it difficult for them to float and keep warm and they may eventually die. Solid waste in the water -> growth of algae which depletes water of oxygen and kills marine life
Air pollution discolours and corrodes buildings and statues
Different Strategies to Solve Pollution
Reduce, reuse, recycle
Grow your own food, eat locally, redecorate with eco-products, buy energy-efficient appliances with ‘energy star’ label, reduce your heating, reduce your electricity use, try alternative energy devices, buy durable goods, install a hot water heat recycling unit to reduce electricity/fuel burned for domestic heating, pack your refrigerator more tightly to reduce cooled air, reduce usage of refrigerator and air-conditioners, use a reel lawnmower, walk/public transport
Investigations
Types of Questions Answered Using Scientific Method
Physical sciences, where it is possible to observe natural phenomena of various kinds and to make hypotheses about how systems work
Steps in Scientific Method
Aim (question you are trying to answer)
Hypothesis (relate dependent/independent variables, what you think will happen)
Equipment (be precise inc. measurements)
Method (past tense, starts with verb, impersonal, steps, concise & precise)
Results (table/graph)
Conclusion (relates directly back to the hypothesis, 1-2 sentences, e.g. …was proven/not proven)
Discussion (what went wrong, how could the experiment be improved, other experiments that might be done)
Senses - taste, touch, smell, see, and hear
Inference - form an opinion by reasoning
Generalisation - make a statement that is true of most cases
Hypothesis – a suggestion or guess that tries to explain something
Repeating or pooling measurements and averaging
COWS - change (I – independent)
MOO – measure (DON’T – dependent)
SOFTLY - same (CARE – control)
SAFELY – risk assessment, look for dangers
REPEATEDLY – repeat x5
Dynamic Earth
Crust – makes up part of the lithosphere, thinnest layer 8-50km
Mantle – thickest 3000km, liquid
Core – outer core 2000km thick, molten nickel & iron. Inner core 1400km thick, solid nickel & iron
Asthenosphere – the upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection, is thought to occur
Lithosphere – the hot outer part of the earth consisting of the crust and upper mantle
Biosphere – the regions of the surface, atmosphere, and hydrosphere of the earth occupied by living organisms
Hydrosphere – all the waters on the earth’s surface, such as lakes and seas, and sometimes including water over the earth’s surface, such as clouds
Atmosphere – the envelope if gases surrounding the earth or another planet
Theory – a supposition or a system of ideas intended to explain something
Law – the system of rules that a particular country or community recognises as regulating the actions of its members
Fossil Formation
A leaf falls from a tree and settles in the mud at the bottom of the swamp
Layers of mud and dirt settle over the leaf and bury it
The mud compacts together and forms rock
The rock is pushed up by forces from within the earth and is then eroded
Fossil leaves in the form of coal can be exposed in a hillside
Plate Tectonics
Earth's outer layer is made up of plates, which have moved throughout Earth's history
Godwana & Laurasia
The rigid slabs of lithosphere
Convection Currents
Hot air and liquids rise and so does hot molten rock.
Likewise ’cool’ rock drops, heat from deep within the earth causes the molten rock of the mantle to move upwards. When this hot mantle rock comes into with the relatively cold crust it cools and sinks. Convection currents in the mantle are the result
Interactions at Plate Boundaries
Spreading boundaries – plates move apart, aka constructive boundaries, rock being formed
Collision boundaries – one plate collides with another, aka destructive boundaries, rock melted and returned to the mantle for recycling
Transform or scraping boundaries – plates scrape along each other, aka conservative boundaries, conserve rock (does not create/break)
The rock oceanic plates are denser than the plates that the continents sit on. When they hit, the heavier the oceanic plate is forced under the continental plate at an angle of 20o to 60o to the surface. This angle dive is called a subduction zone
When two continental plates collide, the crumple and fold – mountain formed
Plates that scrape along each other along a transform boundary – earthquake
formed
Tectonic plate sinks into the mantle, becomes very hot, rock melts, molten rock gradually make its way up to surface of earth through a series of cracks. As layer upon layer of lava builds up, a volcano is formed
Sedimentary, Metamorphic, Igneous
Sedimentary – formed from particles that have settled on a surface. Found in where there used to be oceans and seas or other bodies of water (e.g. gravel, coal, sand, shale)
Metamorphic – formed or changed by heat or pressure. Found in deep underground, at the base of mountains, in zones radiating from intrusions of magma underground, on glaciated terrain after transportation by ice, or on the surface of eroded mountains (e.g. marble, sand, slate)
Igneous – formed by the action of a volcano. Found in the surface in areas of current or past volcanism or in uplifted and eroded areas of past plutonic intrusions, deep underground nearly anywhere, or in areas of past or present glaciation, where igneous rock has been eroded and deposited (e.g. sand, granite, gneiss)
ACDC
An energy source, such as a battery
A conductor (wires) for the electricity to flow through
Something to use up the electrical energy such as a globe or a motor
A switch to turn on and off the current
Current – a flow of electricity which results from the ordered directional movement of electricity charged particles
Voltage – a measure of the amount of energy available to push charges around a circuit
Chemicals inside a cell cause chemical reactions which generate free electrons which constitute the current
Conductor – a substance that allows current to flow through it easily. Metals are good conductors of electricity
Insulator – materials that do not normally allow current to pass through them. Plastic and rubber are very effective insulators
The resistance – part of a circuit that causes electrons to lose most of their energy
AC – alternating current (an electrical generator makes and supplies electricity) backwards and forwards
DC – direct current (electromagnetic induction is the production of voltage across a conductor moving through a magnetic field) one direction
CRO – oscilloscope (a voltmeter with a screen. The vertical movement of the light on the screen shows the size of the voltage)
Hz – Hertz
Ohm’s Law (V=IR) Volts (V) = Amps (I) x Ohms (R)
As voltage across a resistor increases, current increases proportionally
If voltage across a resistor remains constant, increasing the value of the resistor decreases the current flowing through it by the same position (i.e. double resistors, ½ current)