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30 Cards in this Set
- Front
- Back
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How many calories of energy does the sun flow to the earth each year
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13 x 10^23 calories
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How much the the energy from the sun is reflected back into space?
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30%
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How much of the energy from the sun is absorbed by the atmosphere?
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20%
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How much of the energy from the sun reaches the surface of the earth and is converted to heat?
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50%
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What is energy?
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Energy is the ability to do work.
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What kind of system is the earth?
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The earth is an open system.
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What is the first law of thermodynamics?
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Energy can be changed from one form to another, but it cannot be created or destroyed.
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What is the second law of thermodynamics?
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Ø In all energy exchanges and conversions – if no energy leaver or enters the system under study – the potential energy of the final state will always be less than the potential energy of the initial state.
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A system without energy input will always seek _____.
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the lowest energy state
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What is the exergonic process?
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· A process in which the potential energy of the final state is less than that of the initial state is one that releases energy.
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What is the endergonic process?
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If the potential energy of the products is higher than the potential energy of the reactants.
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Whend does the endergonic process happen?
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When there is energy input.
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All natural process proceed towards what?
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Entropy
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Cells ______, _______, and ______ energy.
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capture, convert, store
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At each transformation, what happens to heat energy?
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Heat energy is dissipated.
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what is oxidation?
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oxidation is the loss of an electron, which is often accompanied by a proton.
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what is reduction?
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reduction is the gain of an electron, which is often accompanied by a proton.
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what are three examples of oxidation/reduction reactions?
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respiration, glycolysis, photosynthesis
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why is energy activation important?
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overcomes repulsion between molecules' electrons, and breaks chemical bonds.
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as catalysts, enzymes:
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lower energy of activation, speed up checmical reactions, are not permanantly altered in the process, largely determine the activities of cells, and react with one or more substrates
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most enzymes are _____.
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large globular proteins
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most enzymes contain a ______ ______ _______ site.
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groove shaped active
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what are cofactors?
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nonprotein substances required by enzymes
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what are some types of cofactors?
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ions such as magnesium, conenzymes such as vitamins, nonprotein organic molecules
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what are biochemical pathways made of?
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enzymes working in series
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what are advantages of grouping enzymes in pathways?
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enzymes in a pathway can be segregated in the cell, intermediate products tend not to accumulate, exergonic reactions pull preceding reactions forward
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what is atp made of?
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adenine, ribose, and three phosphate groups, high energy bonds joined by phosphate groups
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what are the most common interconversions are the most common in cells?
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ATP-ADP
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ATP is hydrolyzed to ADP by:
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the removal of a phosphate group, and the release of 7kcal/mol
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Exergonic reactions are linked to:
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endergonic reactions
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