a cell membrane like humans do inside and outside of the body that let things pass through like water. We can use eggs to study the effect of changes in the external environment on the internal environment by having harsh environments like putting the egg in only alcohol and see what happens to the inside of the egg. Diffusion is the movement of a substance down its concentration gradient from a more to a less concentrated area. Meaning if there was more oxygen on one side of the membrane and the
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substances across the cell membrane without the use of energy by the cell. During passive transport‚ substances move down their concentration gradient‚ hence no energy is required. Passive transports can happen through three different channels‚ namely 1. lipid bilayer 2. pore protein 3. carrier protein SIMPLE DIFFUSION What is diffusion? Diffusion is the movement of particles from a high density region to a low density region. No energy is needed and no membrane involves in diffusion
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Osmosis is the spontaneous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration‚ in the direction that tends to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves‚ without input of energy‚ across a semipermeable membrane separating two solutions of different concentrations. Although osmosis does not require input of energy‚ it does use kinetic energy and
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respiration * N – Nutrition = synthesis of organic materials * R – Reproduction = asexual (cell division) * R – Response = to change (environmental) * * 2.1.4 * Compare relative sizes * 1 nm = molecule * 10nm = Membrane * 100nm = Virus * 1 um = Bacteria * 10um (or less) = organelle * 100um (or less) = cell * * 2.1.5 * Calculating Linear Magnification (answer = magnification) 1. Measure scale bar on page e.g. 15mm 2. Convert
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Communication‚ Homeostasis & Energy Communication & Homeostasis Outline the need for communication systems within multicellular organisms‚ with reference to the need to respond to changes in the internal and external environment and to co-ordinate the activities of different organs. Organisms need to respond to external stimuli‚ e.g. temperature‚ oxygen concentration and levels of sunlight. These may be over time‚ e.g. winter fur to summer fur‚ or quickly‚ e.g. changing size of pupils. Internal
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neuron and another cell. Chemical messengers must fulfill four criteria to be considered a transmitter. These four steps include the synthesis of a transmitter substance‚ the storage and release of the substance‚ its interaction with a receptor in the membrane‚ and the removal of the transmitter form the synaptic cleft. The nervous system makes use of two types of neurotransmitters: small-molecule transmitters (acetylcholine‚ amines and A.A) and neuroactive transmitters(peptides) 2. Neurons have developed
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the plasma membrane‚ and to indicate the driving force for each. 3. To determine which way substances will move passively through a dif- ferentially permeable membrane (given the appropriate information on concentration differences). 01_001_016_PhyEx8_AP_Ch01 1/10/08 5:27 PM Page 1 The diffusion of solute particles dissolved in water through a differentially permeable membrane is called simple diffu- sion. The diffusion of water through a differentially perme- able membrane is called
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energy Diversity of animals…more than 1 million species on earth Unifying themes that apply to all physiological processes Physiological Processes Chemical & Physical Laws Rooted in the laws of physics & chemistry Nerve conduction‚ action potentials & ionic currents Gas exchange Animal locomotion and blood flow Muscle contraction and limb movement Anabolic and catabolic metabolism What is Animal Physiology? (continued) Animal Physiology includes behavior‚ ecology‚ anatomy‚ evolution
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the selective diffusion of water and other molecules across membranes‚ which in the case of living organisms‚ the solvent (water) would have net movement across a selective permeable membrane. Osmosis only occurs when a membrane such as that of a cell is permeable to water molecules but not to specific solutes (Tortora & Derrickson 2014). Certain simple molecules such as oxygen‚ water and carbon dioxide can travel across the cell membrane by osmosis‚ a passive process similar to other forms of diffusion
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Instructor: Alan Byboth‚ M.S. 10/4/12 Abstract- The cell is invaluable building block of all biological life on this planet‚ and one of its most important and unique characteristics is its ability to be selectively permeable with its plasma membrane. This outer membrane’s sophisticated mechanisms of transport through its bilayer are vital in maintaining homeostasis in the cell and the entire body. To further understand these mechanisms‚ which can be further described as passive and active
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