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43 Cards in this Set
- Front
- Back
What is energy
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The capacity to do work
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What is kinetic energy? give an example on the cellular level
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The energy ffrom anything that is in motion.
EX: Lysosomes move during the recycling process. They are performing work |
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What is potential energy? give an example on the cellular level
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Stored energy or the potential to do work
EX: Cells store energy obtained through food to use for activities later. |
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What is the relationship between kinetic and potential energy?
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Potential energy is needed for kinetic energy
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What is the first law of thermodynamics? Give an example in a living system
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Energy can bo transferred and transformed but not created of destroyed.
EX: a plant consume light energy and uses that energy to grow |
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If energy cannot be destroyed why do living organisms need a constant input of energy?
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Our energy is released when we use it to to work. We then need to replenish that energy inorder to perform more work
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What is the second law of thermodynamics?
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Every energy transformation increases entropy in the universe.
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What is entropy
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Disorder or randomness
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Describe a specific spontaneous event in terms of total energy and entropy changes.
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In a spontaneous even, total energy is given up and entropy increases
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Edfine free energy , what is the equation and what do the two terms represent
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The portion of a systme's energy that can perform work when temperature in uniform throughtout.
Change G= (Change H) - T(Change S) H: systems total energy G: Free energy S: entropy |
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Describe a specific spontaneous even in terms of the free energy of the initial and final states
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In a spontanious reactions, freee energy is given up in the final state
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What is Change G and is the value positive or negative in a spontaneous reaction?
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This is the difference in the amount of free energy in the final and initial states of a reaction. If it is negative then the reaction is spontaneous
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Define exergonic
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A net release of energy. Change G is less than 0
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Define endergonic
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a net absorption of energy. Change G is positive
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What is the relationship b/w the change in G of a reaction and it's displacement from equillibrium
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When the change in G is = 0, it has reached equillibrium. If a cell has reached metabolic equillibrium it is dead.
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What is metabolism
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the totality of an organisms chemical reactions
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What is catabolism
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the breaking down of complex substances to simple products with a net release of energy. This is exergonic and spontaneous
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What is anabolism
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the building of complex molecules from simpler ones. A net absorption of energy. This is endergonic and nonspontaneous.
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What is meant by coupling in refernece to catabolic and anabolic processes?
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Catabolism is a spontaneous reaction. When catabolsm finishes, it releases energy. This energy is used to start the reactions of the anabolic pathways. So, one reaction loss of energy is another reactions gain.
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What molecule transfers energy b/w catabolic and anabolic reactions
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ATP
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desrcibe the structure of ATP
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There are 3 phospates groups attached to the ribose, which is bonded to adenine
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what is an enzyme
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a catalytic protein
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Wht is the activation energy and how does it affect the rate of a reaction
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Ther energy for starting a reaction that is needed to break bonds in the reactant molecule. This speeds the rate of reaction.
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what is the transition state
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This is the point wen the free energy of a reaction is increaseing and has reached the point where it will start to decrease
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Why should cells need enzymes
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an enzyme speeds a reaction by lowering the activation energy barrier so that the transition state can be reached
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What is a substrate
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the reactant an enzyme acts on
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Describe the induced fit model of substrate binding
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as the substrate binds to the protien, the protein induces a change in the shape of the protein that xauses the active site to embrace
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list the steps in the catalytic cycle
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1. Substrate binds to the active site creating weak
2. Substrate is converted to products 3. Products are released frm enzyme 4. Active site is available for another molecule of substrate |
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What happens to enzyme activity when substrate concentration increases
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There is more of a chance for substrates to bind to enzymes so therefor enzyme activity increases
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What happens to enzyme activity when temperature increases
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Molecules move more rapidly causing substrate binding to occur more frequently
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What happens to enzyme activity when temperature increases dramatically
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enzyme activity decreases because the bonds are disrupted by the high temperatures. This causes denaturation
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What is the optimum pH for enzyme activity
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6-8
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Where do competitive inhibitors bind on an enzyme
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at the active site, permanently blocking any substrates from binding
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Where do non competitive inhibitors bind on an enzyme
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not at the active site
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What happens to an enzyme when a non competitive inhibitor binds to an enzyme
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it causes the enzyme to changes shape, making the active site less receptive to the substrates
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Competitive inhibitors are _____________ inhibitors
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non reversible
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non competitive inhibitors are _____________ inhibitors
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reversible
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What type of bond is involved in competitive inhibitor binding
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covalent
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what is an allosteric site
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a site on an enzyme remote from the active site. This is where a non competitive inhibitor binds
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Catbolism:anabolism :: exergonic:____________
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endergonic
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Most cells connot harness heat to perform work because....
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termperature is usually uniform throughout the cell
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if an enzyme solution is saturate with substrate, the most effective way to obtain an even faster yield of product is to add more ________
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enzymes
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how does ATP transfer energy from exergonic to endergonic processes in the cell
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BY phosphorylation. The addition of phosphate groups which transfers the energy to endergonic processes by phosphorylating other molecules
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