1Where does glycolysis occur?
Cytoplasm.
2What is the first stage of glycolysis?
Phosphorylation of glucose to glucose phosphate using 2 ATP.
3What is the 6C compound split into?
Two molecules of triose phosphate (3C).
4What is the net yield of reduced NAD in glycolysis?
2 reduced NAD.
5Where does the Link Reaction occur?
Mitochondrial matrix.
6What happens during the Link Reaction?
Pyruvate is decarboxylated and dehydrogenated to form acetyl coenzyme A.
7How many CO₂ molecules are produced per glucose in the Link Reaction?
Two.
8What 4C compound does acetyl CoA combine with?
Oxaloacetate.
9What is the 6C compound formed in the Krebs cycle?
Citrate (citric acid).
10How many turns of the Krebs cycle occur per glucose molecule?
Two.
11Name the coenzymes used in the Krebs cycle.
NAD and FAD.
12Where is the Electron Transport Chain located?
On the cristae (inner mitochondrial membrane).
13What is the role of oxygen in aerobic respiration?
It is the final electron acceptor and forms water with protons and electrons.
14What is the theoretical total yield of ATP per glucose?
38 ATP.
15Why is the actual ATP yield often lower than 38?
ATP is used for transport, energy is lost as heat, and protons leak across the membrane.
16What is the product of anaerobic respiration in animals?
Lactate (lactic acid).
17What are the products of anaerobic respiration in yeast?
Ethanol and carbon dioxide.
18Why is the Krebs cycle necessary?
To produce reduced coenzymes for the ETC and ATP by substrate-level phosphorylation.
19Define Respiratory Quotient (RQ).
RQ = volume of CO₂ produced divided by volume of O₂ consumed.
20What is the RQ for carbohydrates?
1.0.
21Why do lipids have a lower RQ (about 0.7)?
They have more C–H bonds and require more oxygen for oxidation.
22What does an RQ greater than 1.0 indicate?
Anaerobic respiration is occurring.
23What enzyme removes CO₂?
Decarboxylase.
24What enzyme removes hydrogen?
Dehydrogenase.
25How is ATP made in the Krebs cycle?
By substrate-level phosphorylation.
26What happens to lactate after exercise?
It is converted back to pyruvate or glucose in the liver using oxygen.
27Why can’t the Krebs cycle happen without oxygen?
NAD and FAD cannot be regenerated because the ETC stops.
28What is the function of coenzyme A?
It carries the 2-carbon acetate group.
29How many CO₂ molecules are produced in one turn of the Krebs cycle?
Two.
30What is the total yield of reduced NAD from one glucose molecule?
10 (2 from glycolysis, 2 from the Link Reaction, 6 from the Krebs cycle).