Glycolysis
Where in the cell does glycolysis occur?
Cytoplasm
Where does pyruvate oxidation occur?
Mitochondrial Matrix
What molecule enters the citric acid cycle?
Acetyl-CoA
Which enzyme is responsible for synthesizing ATP in oxidative phosphorylation?
ATP Synthase
Which condition leads cells to rely on fermentation instead of aerobic respiration?
Lack of oxygen
What are the net products of glycolysis per glucose molecule?
2 ATP, 2 NADH, 2 pyruvate
What molecule is pyruvate converted into?
Acetyl-CoA
How many turns of the citric acid cycle are required to fully metabolize one molecule of glucose?
2
What is the final electron acceptor in the ETC?
Oxygen, forming water
What are the two types of fermentation?
Lactic acid fermentation & alcoholic fermentation
One molecule of glucose is broken down into two molecules of what three-carbon compound at the end of glycolysis?
Pyruvate
What byproduct is released during pyruvate oxidation?
CO2
What are the total products of the citric acid cycle per glucose?
6 NADH, 2 FADH₂, 2 ATP, 4 CO₂
What is the role of ATP synthase?
Uses proton gradient to make ATP
What is the purpose of fermentation?
Regenerate NAD⁺ for glycolysis to continue
What molecule is the starting substrate for glycolysis?
Glucose
Which coenzyme is reduced during pyruvate oxidation?
NAD⁺ → NADH
Which molecule is regenerated at the end of the cycle to continue the process?
How many ATP are produced from oxidative phosphorylation per glucose?
26-28 ATP
Why do human muscle cells switch to lactic acid fermentation during strenuous exercise?
The demand for energy exceeds the available oxygen supply, the body cannot rely on aerobic respiration and must instead use an anaerobic pathway to produce ATP quickly.
What happens to ATP in the first few steps of glycolysis?
It is used to phosphorylate glucose and other intermediates.
How many times does pyruvate oxidation occur per glucose molecule?
Twice, once for each pyruvate.
What is the main function of the citric acid cycle?
Generate electron carriers NADH & FADH₂ for the ETC
What happens if oxygen is not available for oxidative phosphorylation?
The ETC shuts down, and ATP production stops
Why does fermentation produce less ATP than aerobic respiration?
It does not use the ETC, so only ATP from glycolysis is produced.