Cell Resp 1
FAD+/FADH and NAD+/NADH
What are electron transporters in cellular respiration?
What is the final electron acceptor in aerobic cellular respiration?
What is Oxygen?
A protein serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction.
What is an enzyme?
Chloroplasts
Where is photosynthesis occurring?
During Step 3 of the Krebs Cycle, the enzyme isocitrates dehydrogenase (IDH) catalyzed the conversion of isocitrate a(alpha)-ketoglutarate. IDH is allosterically activated by ADP at high concentrations. Which of the following best describes how this interaction helps regulate the Krebs Cycle?
A) Low levels of ADP inhibit the krebs cycle because IDH requires ADP as a substrate for the reaction it catalyzes
B) High levels of ADP inhibit the krebs cycle because ADP prevents IDH from catalyzing the conversion of isocitrate to alpha-ketoglutarate
C) High levels of ADP stimulate the krebs cycle, leading to the increase conversion of ADP to ATP during oxidative phosphorylation.
D) Low levels of ADP stimulate the Krebs Cycle, leading to the production of excess ATP that is stored for later use.
C: High levels of ADP stimulate the Krebs cycle, leading to the increased conversion of ADP to ATP during oxidative phosphorylation
Reasoning: At high concentrations, ADP allosterically activates IDH, promotive the conversion of isocitrate to alpha-ketoglutarate. This helps increase the overall rate of the krebs cycle, eventually leading to increased ATP production during oxidative phosphorylation.
Alcohol Fermentation, lactic acid fermentation
What are examples of anaerobic respiration?
Hydrogen/ Protons are Gained
Electrons are gained
What is reduction?
A temporary complex formed when an enzyme binds to its substrate molecule(s).
What is an enzyme-substrate complex?
What is the end result of photosynthesis?
Pepsin, a proteolytic enzyme found in the stomach, is essential for digestion. Pepsin functions optimally at approximately 37 degrees celsius. What would most likely result if pepsin's environmental temperature was lowered from 37 degrees celsius to 25 degrees celsius.
Answers vary but should be around : Pepsin would be less efficient at catalyzing reactions due to not being at optimal temperature.
When Oxygen is gained
Protons/ Hydrogens are lost
Electrons are Lost
What is oxidation?
What is the chemical equation of cellular respiration
C6H12O6 + O2 --> 6CO2 + 6H20
A reaction which releases energy
What is an exergonic reaction?
Input used for cellular respiration that is a product of photosynthesis
What is glucose?
The cytochrome b6f complex is an integral thylakoid membrane protein that forms an electrochemical gradient by pumping protons. In an experiment, researchers apply a toxin to a plant cell that inhibits the cytochrome b6f complex.
Which of the following explains the most likely effect of this toxin on the light reactions of photosynthesis?
A) NADP+ will not be reduced to NADPH
B) Hydrogen ions will move across the thylakoid membrane using simple diffusion
C) Carbohydrates will not be produces in the stroma
D) ATP synthesis will nto occur.
D) ATP synthesis will not occur
Reasoning: ATP synthesis requires an electrochemical gradient to form across the thylakoid membrane. The toxin prevents the cytochrome B6f complex from forming an electrochemical gradient, so ATP synthesis will not occur during the light reaction of photosynthesis.
This is the channel protein that allows for protons (H+) to move down the concentration gradient.
ATP synthase.
How many ATP molecules are produced as a result of aerobic cellular respiration?
What are, ideally, 38 ATP molecules?
The change in shape of the active site of an enzyme so that it binds more snugly to the substrate, induced by entry of the substrate.
What is induced fit?
What is the reaction for photosynthesis?
6CO2 + 6H2O --> C6H12O6 + 6O2
Methotrexate is a drug that is commonly used to treat cancers and autoimmune diseases in humans. It functions by binding to the active site of the enzyme DHFR, preventing both DNA synthesis and excess cell proliferation.
Which of the following terms best describes methotrexate?
A) Allosteric activator
B) Competitive Inhibitor
C) Cofactor
D) Noncompetitive inhibitor
B) Competitive inhibitor
Reasoning: According to the text, methotrexate binds to the active site of DHFR and inhibits its activity. This describes a competitive inhibitor, which functions by binding in place of an enzyme's typical substrate, there by limiting enzyme activity.
What are the parts of cellular respiration that is anaerobic?
What is glycolysis, the formation of Acetyl CoA, and the krebs cycle?
Where does the krebs cycle occur?
Where is the mitochondrial matrix?
A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.
What is a competitive inhibitor?
Where do the light dependent reactions of photosynthesis occur?
The formation of the amino acid tryptophan is catalyzed by the enzyme tryptophan synthase. This enzyme is made up of alpha and beta subunits.
Each type of subunit catalyzes a different step in the tryptophan biosynthesis pathway. The alpha subunit forms an indole molecule from indole-3-glycerol phosphate (IGP), and the beta subunit forms tryptophan from this indole.
Within the tryptophan synthase protein, the active sites of the alpha and beta subunits are connected by a hydrophobic channel. This channel allows the small, hydrophobic indole molecule to diffuse directly from the active site of an alpha subunit to the active site of a beta subunit.
Which of the following statements describes a likely effect of the channel on the process carried out by tryptophan synthase?
A) The indole molecule does not diffuse across the cell membrane before it can be used by the beta summit
B) The product of the reaction catalyzed by the alpha subunit can enter an alternative metabolic pathway occurring near tryptophan synthase in the cell.
C) The energy required to maintain the channel reduces the amount of tryptophan the enzyme can produce
D) The beta subunit's reaction product is transferred efficiently to the alpha subunit, where it serves as a reactant.
A) The indole molecule does not diffuse across the cell membrane before it can be used by the beta subunit
Reasoning: Without the channel in tryptophan synthase, the small, hydrophobic indole molecule could diffuse away from the enzyme and across the cell membrane. So, the channel ensure that the product of the alpha subunit is efficiently transferred to the beta subunit where it becomes a reactant in the fromation of tryptophan.