L15-18: respiration

Question 1

Respiration

Answer 1

Process which occurs in all living cells by which chemical energy is released from cells and used to regenerate high-energy molecules.

Glucose+Oxygen –> carbon dioxide+Water

The energy produced is used to sythesize ATP:

ADP + Pi –> ATP

Question 2

Glycolysis

Answer 2

The breakdown of glucose to pyruvate in the cytoplasm

Question 3

Glycolysis phase 1

Answer 3

Energy investment phase
2ATP –> 2ADP + 2Pi

provides energy for conversion of glucose to intermediate molecules

Question 4

Glycolysis phase 2

Answer 4

Energy pay-off phase

intemidiate molecules converted into pyruvate molecules. Net gain of 2ATP molecules.

Question 5

phase 3 (anaerobic conditions)

Answer 5

Fermentation takes place. Only the 2ATP molecules released in glycolysis are produced.

In plants: pyruvate –> ethanol and carbon dioxide

in animals: pyruvate latic acid

Question 6

phase 3 (aerobic conditions)

Answer 6

Cytric acid cycle takes place in the matrix of mitochondria.

Question 7

Cytric acid cycle

Answer 7

• Pyruvate is broken down into carbondioxide and an acetyl group
• The acetyle group combins with coenzyme A forming acetyle coenzyme A
• The acetyle group in acetyle conenzyme A joins with oxalocetate to produce citrate
• As the cycle proceeds carbondioxide is released and dehydrogenase enzymes remove H ions and electrons which are passed to coenzyme NAD to form NADH
• During a series of enzyme controlled steps citrate is gradually converted back into oxaloacetate which produces ATP and releases carbon dioxide

Question 8

Where doe the Electron Transport Chain occur

Answer 8

Occurs at the cistae, a series of carrier proteins attached to the mitochondrial membrane.

Question 9

Electron Transport Chain

Answer 9

• Electrons are transfered from NADH to the electron transport chain.
• As electrons are passed down the chain energy is released, this energy allows H ions to be pumped from the matrix to the the inner mitochondrial membrane, causing a concentration gradient to develop.
• H ions return to the matrix through a channel in the enzyme ATP synthase.
• The flow of H ions changes the shape of the enzymes active site and converts ADP + Pi into ATP
• Finally H ions + electrons + oxygen –> water

Question 10

Electron Transport Chain total ATP production

Answer 10

• A pair of hydrogen ions passing through the electron transport chain produces 3ATP molecules.
• Overall the Electron transport chain produces 36 molecules.