What are the main stages of cellular respiration

glycolysis, pyruvate oxidation, citric acid cycle, and oxidative phosphorylation

How are aerobic and anaerobic respiration different

aerobic uses oxygen as final electron acceptor while anaerobic uses an inorganic molecule. Aerobic respiration makes more ATP.

What is glycolysis and where does it happen in prokaryotic and eukaryotic organisms

Glycolysis is first series of reactions that begin breaking down glucose into two molecules of pyruvate. Produces small amount of ATP and NADH. Occurs in the cytoplasm for both prokaryotic an eukaryotic organisms.

Describe the energy investment phase of glycolysis.

Glucose is broken down to make it less stable/ reactive. The cell spends ATP to breakdown glucose. 2 ATP is lost. At the end of phase 6 carbon glucose molecule converted into 3 carbon molecules (G3P)

What happens during the energy payoff phase

Two 3 carbon molecules are oxidized and turned into into pyruvate, producing energy. the cell makes 4 ATP (by substrate-level phosphorylation) and 2 NADH.

What are the main events in pyruvate oxidation

• Pyruvate is transported into the mitochondrion (in eukaryotes)

• Each pyruvate (3 carbons) is converted into a 2-carbon acetyl group

• CO₂ is released (one carbon is removed)

• NAD⁺ is reduced to NADH

• The 2-carbon acetyl group is attached to coenzyme A, forming acetyl-CoA

For one glucose molecule, what are the products after pyruvate oxidation

• 2 acetyl-CoA

• 2 NADH

• 2 CO₂

Where does pyruvate oxidation happen in prokaryotes and eukaryotes?

• Eukaryotes: in the mitochondrial matrix

• Prokaryotes: in the cytoplasm

What are the main events and products of the citric acid cycle; how many products

• Acetyl-CoA (2 carbons) enters the cycle

• It combines with a 4-carbon molecule to form a 6-carbon compound

• The compound is oxidized, releasing carbon as CO₂

• Energy is captured in the form of NADH and FADH₂

• A small amount of ATP (or GTP) is made

• The original 4-carbon molecule is regenerated to keep the cycle going

Per one acetyl-CoA:

• 2 CO₂

• 3 NADH

• 1 FADH₂

• 1 ATP (or GTP)

👉 Per one glucose (2 acetyl-CoA):

• 4 CO₂

• 6 NADH

• 2 FADH₂

• 2 ATP