BIO 172 EXAM 2 QUESTIONS AND ANSWERS
What are three ways energy is extracted from glucose?
Glycolysis, Citric Acid Cylce, Oxidative Phosphorylation
What enzyme in the investment phase of glycolysis is responsible for cosumeing ATP to
break down carbohydrates?
Phosphofruktokinase
How many binding sites does phosphfruktokinase have? What binds there?
It has a regulatory and active site. Both bind to ATP.
When ATP binds at phosphfruktokinase's regulatory site, what happens to the reaction
rate?
It decreases, ATP inhibits phosphfruktokinase
Feedback inhibition
When the product of a sequence of reactions can be used to allosterically inhibit on of the
enzymes catalyzing the reaction.
Phase 1 Glycolysis
The energy investment phase. Two ATP are consumed. Fructose-1,6-Biphosphate is the product.
Phase 2 glycolysis
The Cleavage phase. Fructose-1,6-Biphosphate is cleaved into two glyceraldehyde-3-phosphates.
No ATP consumption.
Phase 3 Glycolysis
The Payoff phase. 2 NADH and 4 ATP produced. Pyruvate formed.
Net Products of Glycolysis
2 Pyruvate
2 NADH
2 ATP
How is ATP created in Glycolysis?
Substrate Level Phosphorylation
Substrate Level Phosphorylation
The use of a chemical substrate to transfer a phosphate directly to an ADP molecule and form
ATP.
, Net Equation for Glycolysis
C₆H₁₂0₆ + 2 NAD⁺ + 2 ADP + P → 2 Pyruvate + 2 NADH + 2 H⁺ + 2 ATP
Where does Glycolysis Occur?
The Cytosol
Where does pyruvate go what oxygen is present?
To Acetyl-CoA synthesis and then to the Citric Acid Cycle
Where does pyruvate go when oxygen isn't present?
To fermentation
How is glycolysis linked to the citric acid cycle?
Acetyl-CoA synthesis
What are the products of Acetyl-CoA synthesis?
2 Acetyl-CoA
2 CO₂
2 NADH
Starting materials for Acetyl-Coa Synthesis
2 Pyruvate
2 NAD⁺
2 Coenzyme A
Where does Acetly-CoA synthesis take place?
Intermembrane Space
What is the Purpose of the Citric Acid Cycle?
To extract energy from pyruvate and form high energy electron carriers
Where does the citric acid cycle occur?
Mitochondrial Matrix (Eukaryotes)
Cytosol (Prokaryotes)
Products of Citric Acid Cycle
6 NADH
2 FADH₂
4 CO₂
2 ATP
Citric Acid Cycle Reactants
What are three ways energy is extracted from glucose?
Glycolysis, Citric Acid Cylce, Oxidative Phosphorylation
What enzyme in the investment phase of glycolysis is responsible for cosumeing ATP to
break down carbohydrates?
Phosphofruktokinase
How many binding sites does phosphfruktokinase have? What binds there?
It has a regulatory and active site. Both bind to ATP.
When ATP binds at phosphfruktokinase's regulatory site, what happens to the reaction
rate?
It decreases, ATP inhibits phosphfruktokinase
Feedback inhibition
When the product of a sequence of reactions can be used to allosterically inhibit on of the
enzymes catalyzing the reaction.
Phase 1 Glycolysis
The energy investment phase. Two ATP are consumed. Fructose-1,6-Biphosphate is the product.
Phase 2 glycolysis
The Cleavage phase. Fructose-1,6-Biphosphate is cleaved into two glyceraldehyde-3-phosphates.
No ATP consumption.
Phase 3 Glycolysis
The Payoff phase. 2 NADH and 4 ATP produced. Pyruvate formed.
Net Products of Glycolysis
2 Pyruvate
2 NADH
2 ATP
How is ATP created in Glycolysis?
Substrate Level Phosphorylation
Substrate Level Phosphorylation
The use of a chemical substrate to transfer a phosphate directly to an ADP molecule and form
ATP.
, Net Equation for Glycolysis
C₆H₁₂0₆ + 2 NAD⁺ + 2 ADP + P → 2 Pyruvate + 2 NADH + 2 H⁺ + 2 ATP
Where does Glycolysis Occur?
The Cytosol
Where does pyruvate go what oxygen is present?
To Acetyl-CoA synthesis and then to the Citric Acid Cycle
Where does pyruvate go when oxygen isn't present?
To fermentation
How is glycolysis linked to the citric acid cycle?
Acetyl-CoA synthesis
What are the products of Acetyl-CoA synthesis?
2 Acetyl-CoA
2 CO₂
2 NADH
Starting materials for Acetyl-Coa Synthesis
2 Pyruvate
2 NAD⁺
2 Coenzyme A
Where does Acetly-CoA synthesis take place?
Intermembrane Space
What is the Purpose of the Citric Acid Cycle?
To extract energy from pyruvate and form high energy electron carriers
Where does the citric acid cycle occur?
Mitochondrial Matrix (Eukaryotes)
Cytosol (Prokaryotes)
Products of Citric Acid Cycle
6 NADH
2 FADH₂
4 CO₂
2 ATP
Citric Acid Cycle Reactants
