Year 13 Bio - Periods 3-5

When pyruvate arrives in the matrix of a mitochondrion, what process occurs to remove carbon dioxide and hydrogen?

• Glycolysis

• Phosphorylation

• Decarboxylation and dehydrogenation

• Substrate-level phosphorylation

What molecule is formed when the remainder of the pyruvate combines with coenzyme A (CoA)?

• Pyruvate

• Acetyl CoA

• NAD

• ATP

What is the removal of hydrogen called?

• Decarboxylation

• Dehydrogenation

• Oxidation

• Reduction

What is coenzyme A (CoA)?

• A protein that acts as an enzyme.

• A complex molecule composed of a nucleoside (adenine plus ribose) combined with a vitamin.

• A substrate molecule.

• A product of the Krebs cycle.

What is the common name for the Krebs cycle?

• The glycolysis cycle

• The citric acid cycle

• The link reaction cycle

• The ATP cycle

Where does the Krebs cycle take place?

• Cytoplasm

• Nucleus

• Mitochondrial matrix

• Chloroplast

What happens to the acetyl CoA molecule when it enters the Krebs cycle?

• It is broken down into pyruvate.

• It combines with oxaloacetate (4C) to form citrate (6C).

• It is converted directly into ATP.

• It releases oxygen.

During the Krebs cycle, what gas is released as a waste product when citrate is decarboxylated and dehydrogenated?

• Oxygen

• Hydrogen

• Carbon dioxide

• Nitrogen

For each turn of the Krebs cycle, how many ATP molecules are directly produced?

• Zero

• One

• Two

• Three

What is the type of reaction that produces ATP directly from a phosphate group from one of the substrates in the reactions, as seen in the Krebs cycle?

• Oxidative phosphorylation

• Substrate-level phosphorylation

• Photophosphorylation

• Chemiosmosis