Cellular Respiration 2.2

Question 1

What are the three metabolic pathways in cellular respiration ?

Question 2

What is glycolysis?

Answer 2

Glycolysis is the breakdown of glucose to pyruvate in the cytoplasm.

Question 3

What phase in glycolysis is ATP required for?

Answer 3

ATP is required for the Phosphorylation of glucose and intermediates during the
Energy Investment Phase of glycolysis.

Question 4

What is the energy pay-off stage?

Answer 4

the generation of more ATP during the Energy Pay-Off stage and results in a net gain of ATP.

Question 5

What happens in aerobic conditions in glycolysis?

Answer 5

In aerobic conditions, Pyruvate is broken down to an Acetyl Group that combines with Coenzyme A forming Acetyl Coenzyme A.

Question 6

What happens in the first phase of the citric acid cycle?

Answer 6

In the Citric Acid Cycle the acetyl group from acetyl coenzyme A combines with Oxaloacetate to form Citrate.

Question 7

What happens in the second stage of the citric acid cycle?

Answer 7

During a series of enzyme-controlled steps, Citrate is gradually converted back into
Oxaloacetate which results in the generation of ATP and release of CO 2 .

Question 8

Where does the citric acid cycle occur?

Answer 8

The citric acid cycle occurs in the Matrix of the Mitochondria.

Question 9

What is the role of dehydrogenase enzymes?

Answer 9

Dehydrogenase Enzymes remove Hydrogen and Electrons and pass them to the
coenzyme NAD, forming NADH

Question 10

What happens to the hydrogen ions and electrons from the NADH?

Answer 10

The hydrogen ions and electrons from NADH are passed to the electron transport chain on the inner mitochondrial membrane.

Question 11

What is the electron transport chain?

Answer 11

The Electron Transport Chain is a series of Carrier Proteins attached to the inner mitochondrial membrane.

Question 12

Where does the electron transport chain take place?

Answer 12

Inner Mitochondrial Membrane.

Question 13

What happens to the electrons and hydrogen ions in the Electron Transport Chain?

Answer 13

Electrons are passed along the electron transport chain releasing energy. This energy pumps hydrogen ions across the Inner Mitochondrial Membrane.

Question 14

The flow of these ions back through the membrane protein ATP Synthase results in the production of what?

Answer 14

The flow of these ions back through the membrane protein ATP Synthase results in
the production of ATP.

Question 15

What do hydrogen ions and electrons combine with to produce water?

Answer 15

Finally, hydrogen ions and electrons combine with oxygen to produce water.

Question 16

When and does fermentation take place?

Answer 16

Fermentation takes place in the cytoplasm and in absence of oxygen.

Question 17

What happens during fermentation in animal cells?

Answer 17

In animal cells, Pyruvate is converted to Lactate in a reversible reaction.

Question 18

What happens during fermentation in plant cells?

Answer 18

In plants and yeast, Ethanol and CO 2 are produced in an irreversible reaction.

Question 19

Which produces more ATP: Fermentation or aerobic respiration?

Answer 19

Fermentation results in much less ATP being produced than in aerobic respiration.

Question 20

What is ATP used for?

Answer 20

ATP is used to transfer energy to cellular processes which require energy.