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15 Cards in this Set
- Front
- Back
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Why do all organisms rely on photosynthesis either directly or indirectly |
All living organisms require a continuous supply of energy to stay alive. The process of photosynthesis transfers light energy to chemical potential energy. Photosynthesis supplies living organisms with two essential requirements: an energy supply and usable. |
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Why do all living organisms need a source of carbon? |
All biological molecules (carbohydrates, lipids, proteins, and nucleic acid) contain carbon An organic molecule is a compound including carbon and hydrogen. |
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What can organic molecules be used for? |
Can be used as building bricks for making other organic molecules that are essential to the organism. Can represent chemical potential energy that can be releases by breaking down the molecules in resperation |
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What is the difference between autotrophs and heterotrophs? |
Autotrophs are organisms that can use inorganic carbon source in the form of carbon dioxide Heterotrophs are organisms that need a ready-made supply organic supply of carbon. Heterotrophs depend on autotrophs for both materials and energy |
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What does work in living organism includes: |
The synthesis of complex substances from simpler ones (anabolic reactions) such as the synthesis of polysaccharides from monosaccharides, lipids from glycerol and fatty acids, polypeptide from amino acids, and nucleic acids from nucleotides. The active transport of substances against a diffusion gradient, such as the activity of the sodium potassium pump.
Mechanical work such as muscle contraction and other cellular movements; for example, the movement of cilia and flagella, amoeboid movement and the movement of vesicles through cytoplasm In a few organisms, bioluminescence and electrical discharge |
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Describe the difference between ectotherms and endotherms |
Ectotherms get the thermal energy that warms them from outside their body. Endotherms (Mammals and birds) use thermal energy that is released from within their body (through metabolic reactions) to maintain constant body temperature. Endotherms also maintain a constant body temperature through negative feedback loops. |
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Why is it useful for the reaction involving the complete oxidation of glucose in aerobic conditions to take place in a series of small steps?
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Allow precise control via feedbakc mechanisms. Cell can more usefully harness total available energy than if it were made available at one instant. |
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Why is the reaction to oxidize glucose to carbon dioxide and water difficult to initiate? |
Glucose is a very stable molecule because of the activation energy that has to be added before any reaction takes place. This activation energy is overcome by: Lowering the activation energy using enzymes Raising the energy level of glucose by phosphorylation. |
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Write down the complete reaction for oxidizing glucose into carbon and hydrogen |
C(6)H(12)O(6) + 6CO(2) ---> 6H(2)O + 2870 kJ |
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What happens when ATP is converted into ADP? ADP to AMP? AMP to adenosine? |
ATP ---> ADP o Phosphate group removed o 30.5 kJmol^-1 energy produced ADP ---> AMP o Phosphate group removed o 30.5 kJmol^-1 energy produced AMP ---> adenosine o Phosphate group removed o 14.2 kJmol^-1 energy prodyced o The energy from removing phosohate groups comes from changes in chemical potential energy inthe system. |
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Are the reactions for ATP, ADP, AMP, and adenosine all reversible? |
o These reactions are all reversible. The interconversion of ATP to ADP is all-important in providing energy for the cell. oThe rate of interconversion is enoirmous. In humans, ATP breakdown can be as much as 0.5 kg per minute during strenuous exercise. |
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Describe the role of ATP in cells. |
ATP is said to be the 'energy currency' of the cell. The cell's energy-yielding reactions are linked to ATP synthesis. It is used by the cell in all forms of work ATP is the universal intermediary molecule between energy yielding and energy requiring reactions in the cell. Cells 'trade' in ATP, rather than making use of a number of different intermediates. |
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How is ATP synthesized in the body? |
In respiration, energy released by reorganizing chemical bonds during glycoysis and the krebs cycle is used to make some ATP. Most ATP, however, is generated using electrical potential energy. This energy is from the transfer of electrons by electron carriers in mitochondria and chloroplast. It is stored as a difference in proton concentration across some phospholipid membranes in Mitochondria and chloroplast, which are essentially impermeable to protons. Protons are allowed to flow down their concentration gradient (by facilitated diffusion) through a protein that spans the phospholipid bilayer. Part of this protein acts as an enzyme called ATP synthase. The transfer of three protons allows for the production of one ATP molecule, provided that there is an ADP and inorganic phosphate group available. |
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What is chemiosmosis? Where does it take place? |
A process in which ATP is synthesized. It takes place within the chloroplasts and mitochondria. |
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What does a hydrogen ion consist of? |
One proton and one electron. The loss of an electron leads to a hydrogen ion, which is a single proton. |
