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Bio 110
Purdue University Exam 2
61
Science
Undergraduate 1
10/09/2012

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Term
potential energy
Definition
energy not doing work, such as energy stored in chemical bonds
Term
kinetic energy
Definition
energy associated with movement
Term
free energy
Definition
(G) energy that is available for doing useful work after there has been allowance for the increase or decrease of disorder
Term
entropy
Definition
(S) a measure of the degree of disorder in any system
Term
spontaneous reactions in a closed system are always accompanied by an increase in ______.
Definition
entropy
Term
enthalpy
Definition
(H) the total energy of a system
Term
endergonic
Definition
a chemical reaction in which the products have higher free energy than the reactants, thereby requiring free energy input to occur.
Term
exergonic
Definition
a chemical reaction in which the products of the reaction have lower free energy than the reactants, resulting in a release of free energy
Term
activation energy
Definition
the energy barrier that blocks the tendency for a chemical reaction to occur, this is the amount of energy needed for the reaction to begin
Term
catalyst
Definition
a substance that accelerates a reaction without being consumed in the overall course
Term
What is used to lower activation energy?
Definition
catalyst
Term
Biological catalyst
Definition
enzyme
Term
enzyme
Definition
a catalyst, protein, speeds up reaction
Term
What is the relationship between enzymes and activation energy?
Definition
Enzymes lower the activation energy
Term
coenzyme
Definition
a non-protein organic molecule that plays a role in catalysis by an enzyme
Term
prosthetic group
Definition
any non-protein part of an enzyme
Term
Kinetic energy vs. Potential Energy
Definition
Kinetic energy is in movement and potential energy is stored energy.  The two types of energy can be converted back and forth
Term
cofactor
Definition
an inorganic ion that is weakly bound to an enzyme and required for its activity
Term
substrate
Definition
the molecule on which an enzyme exerts catalytic action
Term
Energy is...
Definition
the ability to do work, the capacity for change, usually related to the changes in the chemical composition and propertied of molecules
Term
Different forms of energy
Definition
chemical, electrical, heat, light, and mechanical
Term
Two basic types of energy?
Definition
potential and kinetic
Term
What do the laws of thermodynamics help us do?
Definition
understand how organisms and cells harvest and transform energy to sustain life
Term
What are the laws of thermodynamics?
Definition

1. energy is neither created nor destroyed

2. Disorder tends to increase

Term
Explain the first law of thermodynamics.
Definition
Energy can not be created or destroyed but it can be converted between different types of energy
Term
Explain the second law of thermodynamics.
Definition
Although the first law is true some of the energy becomes unavailable, no physical process or reaction is perfect, unusable energy increases in every reaction
Term
What is the function of active site?
Definition
the place where the substrate connects to the enzyme
Term
thylakoid
Definition
a sac within a chloraplast that contains all the chlorophyll as well as the electron carriers of photophosphorylation.
Term
grana
Definition
stack of thylakoids
Term
stroma
Definition
small opening in the plant epidermis that permits gas exchange, bounded by cells that control the opening size
Term
Pigment absorbs____
Definition
Light
Term
What type of pigment is associated with chloroplasts?
Definition
chlorophyll, it is green
Term
What is the job of chlorophyll?
Definition
traps light energy for photosynthesis
Term
photosystem
Definition
a light-harvesting complex in the chloroplasts thylakoid composed of pigaments and proteins
Term
Antenna complex also known as the light harvesting complex
Definition
a group of molecules that absorb light energy and transfer it to a reaction center
Term
reaction center
Definition
a group of electron transfer proteins that receive energy from light absorbing pigments and convert them to chemical energy by redox reactions
Term
light reactions
Definition
the initial phase of photosynthesis, light energy is converted into chemical energy
Term
catabolic vs anabolic
Definition
catabolic break down and anabolic build up
Term
What is the difference between an enzyme and most other catalysts
Definition
it is specific, it usually recognizes and binds to only one or a few closely related reactants and catalyizes only a single chemical reaction
Term
The reactants of an enzyme are called____.
Definition
substrates
Term
Where does the specificity of an enzyme come from?
Definition
the exact shape and chemical properties of its active site
Term
What are the nonprotein partners for an enzyme?
Definition

cofactor- inorganic ions that bind to certain enzymes

coenzyme- carbon containing molecule that that adds or removes chemical groups from the substrate

prosthetic groups- permanently bound to enzyme

Term
metabolic pathway
Definition
product of one reaction is the substrate for the next
Term
How are metabolic pathways regulated?
Definition

1. control the amount of an enzyme

2. regulate enzyme activity

3. feedback inhibition

Term
How are enzymes regulated?
Definition
inhibitors
Term
irreversible inhibitor
Definition
covalently bonds to an amino acid chain at the active site of an enzyme, the enzyme is permanetly inactive
Term
What is a reversible inhibitors and what are the two types?
Definition
can be undone, competitive and non competitive
Term
Competitive inhibitor vs noncompetitive inhibitior
Definition

competitive- a substrate that fits into the active site but does not activate it, like a key that fits into the lock but does not unlock it, these can be pulled out of the enzyme when there is low concentrations of the substrate

noncompetitive- binds to an enzyme that causes a change in the active site so it may no longer bind, they can also become unbound

Term
feedback inhibition
Definition
the final product inhibits the enzyme that catalyzes the commitment step, high concentrations of the end product shuts off the enzyme. The cookie example in class.
Term
In what two ways are enzymes affected by the environment?
Definition

pH- Can change the shape of proteins, enzymes, H+ concentration, different enzymes work better at different pH levels

Temperature- enzymes generally increase reaction speed as the temperature increases, but if the temperature is too high enzymes can become inactive

Term
ATP is used in a cell as
Definition
an energy currency
Term
ATP is made up of...
Definition
nitrogenous base adenine bonded to ribose which is attached to a sequence of three phosphate groups
Term
The hydrolysis of one ATP molecule results in___.
Definition
free energy, ADP and inorganic phosphate ion
Term
Where does the light reaction take place?
Definition
thylakoid membrane
Term
Where does the dark reaction take place?
Definition
stroma
Term
What are the inputs and outputs for the light reactions?
Definition

input: light, water, NADP+, ADP, Pi

output: O2, NADPH, ATP

Term
What is photosystem II job?
Definition
absorbs light energy and oxidizes water
Term
What is the purpose of photosystem I?
Definition
absorb light energy and energize electrons, reduces NADP+
Term
What are the three phases of the dark reactions?
Definition
Carbon fixation, reduction, and regeneration
Term
Oxidation and Reduction
Definition

Leo says Ger

Loss of electrons oxidized

Gain of electrons reduced

Term
the reaction center
Definition
collects energy and stores it in an electron
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