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Bio Test 3
SEXCELLENCE
67
Biology
Undergraduate 1
03/28/2010

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Term
Metabolic Pathway
Definition
A series of chemical reactions that either builds a complex molecules (anabolic pathway) or breaks down a complex molecule into simpler compounds (catabolic pathway).
Term
Entropy
Definition
A measure of disorder, or randomness.
Term
The 2 Laws of Thermodynamics
Definition
1: Conservation of Energy.

2: The Principle that every energy transfer or transformation increases the entropy of the Universe.
Term
Energy Coupling
Definition
In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction. (ATP cycle)
Term
Phosphorylation
Definition
Covalent bonding of molecules to a phosphate group.
OR (her def) Transfer of a Phosphate Group.
Term
Induced Fit
Definition
Induced by entry of the substrate, the change in shape of the active site of an enzyme so that it binds more snugly to the substrate.
Term
Coenzyme
Definition
An organic molecule serving as a cofactor. Most vitamins function as coenzymes in metabolic reactions.
Term
Competitive Inhibitor
vs
Noncompetitive Inhibitors
Definition
Competitive-A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.

vs

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzyme’s shape so that the active site no longer functions effectively.
Term
Allosteric Regulation (activators & inhibitors)
Definition
The binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site. Can activate OR inhibit an enzyme.
Term
What are the three types of cellular work?
Definition
Transport- Sodium Potassium Pump

Mechanical- Sperm Swimming

Chemical- Production of molecules
Term
How do enzymes lower the activation energy of reactions?
Definition
They put stress on the bonds (weaken them).
Term
Cofactors
Definition
Regulate Enzymes & are Non-protein helper molecules that attach to enzymes.
Term
What is the other name for activation energy?
Definition
Free Energy of Activation
Term
Active Site
Definition
Site where a substrate binds to an enzyme.
Term
Cellular Respiration
Definition
The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules for the production of ATP
Term
Fermentation
Definition
A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
Term
How does carbon monoxide kill you?
Definition
It bonds to hemoglobin better than O2 but does not fulfill its role.
Term
Where are chloroplasts mostly located within leaves?
Definition
The mesophyll
Term
Which stage of aerobic cellular respiration also occurs in fermentation?
Definition
Glycolysis
Term
What is the total number of ATP’s produced from the complete combustion of one glucose molecule during cellular respiration?
Definition
36 to 38 ATP molecules.
Term
What are the three main steps of cellular respiration, and where does each of these events occur?
Definition
Glycolysis- Cytosol of Cell

Citric Acid Cycle- Matrix of Mitochondria

Oxidative Phosphorylation- Cristae of Mitochondria
Term
What are the two phases of glycolysis?
Definition
Energy investment phase, Energy payoff phase
Term
What is the intermediate product that is formed by the end of the 1st phase of glycolysis?
Definition
G3P
Term
G3P (glyceradlehyde-3-phosphate)
Definition
A three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis.
Term
What are the five products of glycolysis and how many of each are produced (net) from one molecule of glucose?
Definition
2 Pyruvate
2 H2O
2 ATP
2 NADH
2 H+
Term
Pyruvate goes to what Ion which then combines with x to form final product y?
Definition
Pyruvate → Acetate Ion + Coenzyme A → Acetyl CoA
Term
What are the net products of the citric acid cycle?
Definition
2CO2
1 ATP
3 NADH
FADH2
Term
Chemiosmosis
Definition
An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Most ATP synthesis in cells occurs by chemiosmosis.
Term
Use ATP as an example in energy coupling.
Definition
In the ATP cycle, energy is put into ADP and a Phosphate group to produce ATP and H2O, which then releases energy when the hydrolysis of ATP occurs.
Term
C4 Plant
Definition
A plant in which the Calvin cycle is preceded by reactions that incorporate CO2 into a four-carbon compound, the end product of which supplies CO2 for the Calvin cycle.
Term
Acetyl CoA
Definition
The entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.
Term
Alcohol Fermentation
Definition
Glycolysis followed by the conversion of pyruvate to carbon dioxide and ethyl alcohol.
Term
Catalyst
vs
Enzyme
Definition
A chemical agent that increases the rate of a reaction without being consumed by the reaction.
vs
A macromolecule serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.
Term
Lactic Acid Fermentation
Definition
Glycolysis followed by the conversion of pyruvate to lactate, with no release of carbon dioxide.
Term
Alcohol Fermentation
Definition
Glycolysis followed by the conversion of pyruvate to carbon dioxide and ethyl alcohol.
Term
Glycolysis
Definition
The splitting of glucose into pyruvate. Glycolysis occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration.
Term
Electron Transport Chain
Definition
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
Term
NAD+ & NADH
Definition
Nicotinamide adenine dinucleotide, A coenzyme that can accept An electron and acts as An electron carrier in the electron transport chain.
Term
Oxidative Phosphorylation
Definition
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.
Term
Substrate-Level Phosphorylation
Definition
The formation of ATP by an enzyme directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.
Term
Citric Acid Cycle
Definition
A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing pyruvate to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; the second major stage in cellular respiration.
Term
What are the three uses/functions of glucose in plants?
Definition
Cellular Respiration, Building Cellulose, Food storage as starch
Term
ATP Synthase
Definition
A complex of several membrane proteins that provide a port through which protons diffuse. This complex functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. ATP synthases are found in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotes.
Term
Transpiration
Definition
How water goes up plants. --
Term
Calvin Cycle
Definition
The second of two major stages in photosynthesis (following the light reactions), involving (carbon) fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate.
Term
CAM Plant
Definition
A plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. In this process, carbon dioxide entering open stomata during the night is converted to organic acids, which release CO2 for the Calvin cycle during the day, when stomata are closed.
Term
Carbon Fixation
Definition
The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, another photosynthetic organism, or a chemoautotrophic prokaryote).
Term
Mesophyll
Definition
The ground tissue of a leaf, sandwiched between the upper and lower epidermis and specialized for photosynthesis. Where CO2 is incorporated into the four carbon compound in C4 plants.
Term
NADP+ & NADPH
Definition
Nicotinamide adenine dinucleotide phosphate, An electron acceptor that, as NADPH, temporarily stores energized electrons produced during the light reactions.
Term
Photosystem (in general)
Definition
A light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. There are two types of photosystems, I and II; they absorb light best at different wavelengths.
Term
Photosystem I
Definition
One of two light-capturing units in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P700 chlorophyll a at its reaction center.
Term
Photosystem II
Definition
One of two light-capturing units in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll a at its reaction center.
Term
Photophosphorylation
Definition
The process of generating ATP from ADP and phosphate by means of a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis.
Term
Reaction-center Complex
Definition
A complex of proteins associated with a special pair of chlorophyll a molecules and a primary electron acceptor. Located centrally in a photosystem, this complex triggers the light reactions of photosynthesis. Excited by light energy, the pair of chlorophylls donates an electron to the primary electron acceptor, which passes an electron to an electron transport chain.
Term
Light-harvesting Complex
Definition
A complex of proteins associated with pigment molecules (including chlorophyll a, chlorophyll b, and carotenoids) that captures light energy and transfers it to reaction-center pigments in a photosystem.
Term
Primary Electron Acceptor
Definition
In the thylakoid membrane of a chloroplast or in the membrane of some prokaryotes, a specialized molecule that shares the reaction-center complex with a pair of chlorophyll a molecules and that accepts an electron from them.
Term
Light Reactions
Definition
The first of two major stages in photosynthesis (preceding the Calvin cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process.
Term
Chlorophyll a
Definition
A photosynthetic pigment that participates directly in the light reactions, which convert solar energy to chemical energy.
Term
Carotenoid
Definition
An accessory pigment, either yellow or orange, in the chloroplasts of plants and in some prokaryotes. By absorbing wavelengths of light that chlorophyll cannot, carotenoids broaden the spectrum of colors that can drive photosynthesis.
Term
Chlorophyll b
Definition
An accessory photosynthetic pigment that transfers energy to chlorophyll a.
Term
What byproduct of cellular respiration is first produced during the pyruvate conversion?
Definition
CO2
Term
What happens as a result of anaerobic cellular respiration that causes muscles to burn?
Definition
Too much lactic acid which causes an increase in K+ ions.
Term
How is lactate from fermentation recycled?
Definition
It is turned back into pyruvate in the liver, which is used in the citric acid cycle.
Term
Bundle Sheath Cells
Definition
In C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of A leaf. Where the calvin cycle takes place in C4 plants.
Term
The 8 Steps of the Citric Acid Cycle
Definition
1. Acetyl CoA adds its two-carbon acetyl group to oxaoacetate, producing citrate.

2. Citrate is converted to its isomer, isocitrate, by removal of one water molecule and addition of another.

3. Isocitrate is oxidized, reducing NAD+ to NADH. Then the resulting compound loses a CO2 molecule.

4. Another CO2 is lost, and the resulting compound is oxidized, reducing NAD+ to NADH. The remaining molecule is then attached to coenzyme A by an unstable bond.

5. CoA is displaced by a phosphate group, which is transferred to GDP forming GTP, a molecule with functions similar to ATP that, in some cases, is used to generate ATP.

6. Two hydrogens are transferred to FAD, forming FADH2 and oxidizing succinate.

7. Addition of a water molecule rearranges bonds in the substrate.

8. The substrate is oxidized reducing NAD+ to NADH and regenerating oxaloacetate.
Term
What are the reactants in glycolysis? (5)
Definition
1 Glucose
2 NAD+
2 ATP
4 Electrons
4 Hydrogen Ions
Term
Pigment
Definition
Substance that absorbs visible light.
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