Cellular respiration

Question 1

what is the formula for cellular respiration?

Answer 1

C6H12O6 + 6O2 –> ATP + 6CO2 + 6H20

Question 2

what are the reactionsthat compose cellular respiration?

Answer 2

1. Glycolysis (cytoplasm)
2. Kreb’s cycle (matrix)
3. Hydrogen transport mechanism (inner membrane/cristae)

Question 3

Know the structure of a mitochondrion

Answer 3

see diagram

Question 4

What does ATP stand for?

Answer 4

Adenosine triphosphate

Question 5

what is ATP comprised of?

Answer 5

3 phosphate groups, a ribose sugar and an adenine

Question 6

what happens when you convert ATP to ADP + Pi ?

Answer 6

it is an exothermic reaction

energy is released to drive chemical and physical processes in cells

Question 7

what happens when you convert ADP + Pi to ATP?

Answer 7

endothermic reaction. it uses energy from cellular respiration.

Question 8

What Happens in glycolysis under aerobic conditions?

Answer 8

KNOW DIAGRAM

Question 9

What are the enzymes used in glycolysis under areobicconditions?

Answer 9

Hexokinase - converts glucose to glucose phosphate.

Glucose isomerase - converts glucose phosphate into fructose phosphate.

Question 10

What is the pathway of molecules in glycolysis under aerobic conditions?

Answer 10

glucose –> Glucose phosphate –> fructose phosphate –> Fructose biphosphate –> glycerate 3-phosphate –> phospho-glycerate –> pyruvate.

Question 11

what is the net productionof ATP in glycolysis under aerobic conditions?

Answer 11

2

Question 12

Know the Kreb’s cycle diagram.

Answer 12

See diagram

Question 13

wheredoes the Kreb’s cycle occur?

Answer 13

in the matrix

Question 14

what is therole of the Kreb’s cycle?

Answer 14

To generate 1 ATP molecule, and to generate hydrogen.

Question 15

what is the path way of the Kreb’s cycle?

Answer 15

Pyruvate (3C)–> Acetylcoenzyme A (2C) –> Citrate (6C) –> 5C compound –> 4C compound

Question 16

Know the hydrogen transport mechanism.

Answer 16

SEE DIAGRAM

Question 17

What is happening at site 1?

Answer 17

NADH delivers its hydrogen to the beginning of the enzyme/proton pump complex.

Question 18

What is happening at site 2?

Answer 18

electrons are stripped away from the hydrogen leaving a proton (H+)

Question 19

What is happening at site 3?

Answer 19

the electrons are passed down the complex in a series of oxidation/reduction reactions. These reactions release energy that drives the proton pumps.

Question 20

What is happening at site 4?

Answer 20

protons are pumped into the intermembrane space, creating a high concentration zone of H+. A diffusion gradient is established.

Question 21

What is happening at site 5?

Answer 21

H+ has a high tendency to move back into the matrix, but this can only occur via ATPase (which also includes a protein channel). AsH+ passes through ATPase, kinetic energy is released. This KE is used in conjunction with ATPase to synthesise the majority of the ATP that is produced in a cell (34 theorectically)

Question 22

What is happening at site 6?

Answer 22

Note that oxygen is critical to the whole process in that it is the final electron (and H+) acceptor. Oxygen combines with H+ and e- to form water.

Question 23

Describe Glycolysis under anaerobic conditions

Answer 23

SEE DIAGRAM.

In the absence of oxygen, e.g., intense exercise, pyruvate is temporarily converted to lactic acid. This lactic acid formation is termed as an ‘oxygen debt’, as we now owe our tissues (muscles) oxygen which is needed to break down the lactic acid.

Question 24

what is the pathway of glycolysis under anaerobic conditions?

Answer 24

Triose phosphate –> Glycerate 3-Phosphate –> Pyruvate –> lactic acid (lactate)

Question 25

What is NAD+ ?

Answer 25

it is a vitamin derivative, and it is called a co-enzyme

Question 26

what is an example of a co-enzyme? (not NAD+)

Answer 26

FAD (Kreb’s Cycle)