Biology

ASSIGNMENT #1 NASC 1083

BIOLOGICAL SCIENCE

Rubyna May L. Espiritu

Sir Adrian Guinto

BSEDSS 1-1N

November 15, 2012

The Characteristics of Life

There are many properties or the signs of life that the living organisms have. In the book of biology of Mrtinez and Nazareno, there are nine characteristics of life just said and those are :

a. Living things are highly organized and contain many complex chemical substances ;

b. Living things are made up of one or more cells, which are the smallest unit that can be said to be alive;

c. Living things use energy;

d. Living thins have definite form and a limited size;

e. Living things have definite life span;

f. Living things grow;

g. Living things respond to change in the environment;

h. Living things reproduce; and

i. Living things evolve or change over the period of time.

Redi and Pateur

In the book of Practical Biology (a modular approach), Redi diprove spontaneous generation when he placed the rotting meat in covered and uncovered jars, and noted that maggots formed onkly in the uncovered jar. The logic ? Well, we found out that maggots are baby flies and they come from the fly egg.

While Pasteur demonstrataed that broth boiled in a swan-neck flask protected from airbone microbes by curve in the flaks’s neck, which trapped including the microbes. But if he broke the swan-neck and waited a couple of days, microbe growth occurred. there was nothing “unfit” about boil broth or the air around it: both were perfectly suitable for bacterial growth.

Explanation on How Life Originated

Scientists agree that the conditions of early earth were different fromthose existing today. The primitive atmosphere was probably quite unlike the present atmosphere. It may have contain Mathane (CH4), Ammonia (CH3), Hydrogen (H2) and water vapor (H2O). rains probabaly fell on the barren rock and formed oceans. The planet was probabaly bombarded with energy in the form of ultraviolet and lighting.

In addition, the temparature was higher, and there are more sources of energy for producing chemical change.

Buffon and Lamarck

Georges Buffon was the one of the first to propose an idea other than divine creation. He found it striking that the earth and living things were all composed of the same type of the particles or element.

Jean Baptiste Lamarck from his studies of fossils and living organisms that evolution was driven by the sentiments interieurs or felt need of an organisms. Animals could change over generations if their environment dictated that they needed change to survive.

Theories of Evolution and Natural Selection

Evolution . That organism change based on the conditions present in their environment. It proposed by Lamarck and for addition, these characteristics resulting from these changes are passed on from one generation to the next.

It was Georges-Louis :Leclerc de Buffon w ho first studied and developed a concept that all living things are continuously changing.

Erasmus Darwi8n, Charle’s grandfather, also believed that species change through modification in a form which is passed onto their offspring.

Natural Selection is th e process of evolution an d it is based on the following principles:

1. There are rapid production of offspring on each generation.

2. Variations which are inherited exists in this population of organisms.

3. Characteristics which cause them to be fit in their environment have better chances of survival than those which are less fit. This capacity of organisms to survive and reproduce successfully is called natural selection.

Isomers

In the book of biology by Campbell , variation in the architecture of organic molecules can see in isomers , compounds that have the same molecular formula but different structures and hence different properties.

Example is the two butanes, which both have the molecular formula but differ in the covalent arrangement of their car bon skelton. The skeleton is straight in butane, but branched in isobutene. We will examine the three types of isomers: structural isomers, geometric isomers and enantiomers.

Polymers

The subunits of polymers are called monomers. Monomers combine to form polymers through process called dehydration or condensation where matter is dissolved or lost.

Three Structures of Polymers

Polysaccharides which a very large molecules can formed by joining together by many monoccharides units. It is the form in which living things store sugar.

Starch is a very large molecules forms by joining together hundreds of glucose molecules.

Glycogen is an e4ven large molecules consisting of hundreds or even thousands of glucose molecules.

Cellulose is found only in the plant and help to support it by giving it the strength and rigidity. It is the major component of wood.

Saturated and Unsaturated Fat

The example of saturated hydrocarbon chains at a room temperature is the butter while the unsaturated hydrocarbon chains or fat are liquid at a room temperature is oil.

Lipids

The fats and oil are the examples of Triglycerides in element CHO and function as a source of energy.

The example of Phospholipids ( CHOP) is lecithin and it is the component of plasma membrane.

The examples of Steroids (CHO) is cholesterol, testosterone and estrogen which are the component of plasma membrane hormone.

The last is the example of the waxes which have the element of CHO is cuticle and earwax that use as a protective covering.

Primary Structure of Protein

Based on Martinez and Isagani book, a complete protein contains one or more polypeptide chains and may contain groups that are important to its proper function.

Based on Capco and Yang, the primary structure of protein is made up of carbon, hydrogen, oxygen and nitrogen a toms. Sulfur, phosphorus and iron may also be present. The fundamental building blocks of protein are amino acid.

Bonds in Protein

Proteins are group of amino acid. An amino acid has an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other. These groups can perform bonds with each other. As a result of this bond, very long chains of amino acid can be put together. The bond that joins two combine acids is known as a peptide bond.

Globular and Fibrous Protein

The globular protein is the polypeptide that are so tightly folded in the spherical or globular shapes and insoluble in water. Hemoglobin is the component of the vertebrate blood to transport oxygen.

Fibrous protein is the polypeptide are arrange parallel along the single axis to produce long fibers or sheet. Keratin is the principal component of hair skin and nails. Silk is the pleated sheet protein by silk moth and spiders.

The Sugar in Nucleic Acid and Starch

In nuclweic acid, the sugar together with phosphate used as composing strand while the starch is normally broken down to simple sugars during digestion in mouth.

Fuel Engine and the Cell’s breakdown of Glucose

In the book of opez Dee (et. al), mitochondrion releases energy in foof.

The function of the mitochondrion maybe compared to a jeepney engine. Both are machines that releases energy from fuel. In a jeepney engine, there is a rapid burning releases energy which causes the wheel to move. But much of the released e nergy is lost as heat.

In the mitochondrion, the energy lost as heat is less. Here, the combination of sugar with oxygen is slow and occurs in several steps. The sugar molecule breakdown little by little and the energy released is trapped at once in the ATP molecules. Thus, not much energy is lost or wasted.

Cell Metabolism

The adenosine triphosphate or ATP is a nucleotide composed of adenine sugar and three phosphate units and an energy rich compound. The NAD is t he nicotinamide adenine dinucleotide, an electron acceptor or donor in many metabolic reactions. The FAD or flavine adenine dinucleotide is an electron acceptor in the respiratory chain. The Krebs cycle is the degregation (oxidation) of the 2-carbon acetyl coenzyme A occurs in a cyclic sequence and also called as tricarboxylic acid cycle(TCA cycle) and the citric acid cycle. The cytochromes which is several iron-containing pigments that serve as electron carrier in aerobic repiration and the last is the oxygen which is the final acceptor in aerobic respiration.

Absence of Oxygen

In the book of Hickman Jr. (et. al), under anaerobic conditions, glucose and other six carbon sugar area first brokendown stepwise to a pair of 3-carbon pyruvic acid molecule of ATP and for atoms of Hydrogen . But in the absence of molecular oxygen , further oxidation of pyruvic acid cannot occur because the Krebs cycle and the electron transport system cannot operate and cannot, therefore, provide a mechanism for oxidation of the NADH produce in the glycolysis. The problem is neatly solved in most animal cell by reducing pyruvic acid to lactic acid the end product of anaerobic glycolysis.

In the book of the author Gliceria B. Ramos (et.al), said that cellular respiration is aerobic because it occurs in the presence of oxygen gas. The term anaerobic process involves the conversion of pyruvic acid into other kinds of organic byproduct, such as alcohol and lactic acid. Stored energy derived from glucose is transferred into the chemical bonds of these products.

Extra Metabolic Step of Fermentation

The lactic acid fermentation, which pyruvic acid may also be reduced NADH to form lactic acid. Lactic acid is alsooften formed heavily exercise muscle cells. Strenuous activity uses up more oxygen. When there is a shortage of oxygen, lactic acid formation following glycolysis results, and its accumulation in a muscle cell causes fatigue.

The Electron Acceptors

Under certain conditions, photo excited electrons flow, which uses photo system I (as electron acceptors) but not photo systems II. You can see that cyclic flow is a short circuit: the electron cycle back to the P700 chlorophyll via the same electron transport chain that function in noncyclic flow.. There is no production of NADPH does, however, generate ATP. This is called cyclic photophosphorylation, to distinguish it from photophosphorylation.

The electron acceptor in aerobic respiration is oxygen ang the electron acceptor in fermentation is pyruvic acid.

`

REFERENCE

Atienza V. (et. al). (2012). Biological Science. Text workbook 1st Edition

Bojo P. (2007). Biological Science LET reviewer. C&E Publishing Inc.

Campbell A (1996). Biology Fourth Edition. Corn Lily, Eastern Sierra Nevada, California.

Capco M. (et.al.) (2001). Science and Technology 2nd year. Phoenix Publishing house Inc.

CApco M. (et. Al) (2001). Science and Technology 2nd edition. SIBS Publishing House Inc.

Guinto A. (2012). Practical Biology. A Modular Approach 2nd edition. Manila Phillipines

Hickman Jr. Biology of Animals 6th Edition

Martinez (et. Al) (1995). Biology. St. Bernadette publication Inc.

Ramos B. (et. Al) (2006). Science Fundamentals for HS II. Trinitas Publishing Inc.

Vendivil S. (2000). Bilogy. St. Agustine Publishing Inc.