TOPIC 7 RESPIRATION 7.1 - 7.6

Question 1

What are the Requirements of glycolysis

Answer 1

Not oxygen
First step of aerobic and anaerobic respiration

Question 2

Steps of glycolysis - phosphorylation of glucose

Answer 2

two molecules of ATP are required to provide two phosphate needed for phosphorylation of glucose

Question 3

Steps of glycolysis - phosphorylation of glucose
What does it produces

Answer 3

Two molecules of triose phosphates

Question 4

Steps of glycolysis - oxidation of triose phosphate

Answer 4

After triose phosphate loses hydrogen it forms two molecules of pyruvate

The hydrogen ion are collected by NAD which reduces coenzyme

Question 5

Steps of glycolysis - oxidation of triose phosphate what does it produces

Answer 5

Two reduced NAD
*even tho total of 4 ATP Were produced

Question 6

Where does glycolysis

Answer 6

Cytoplasm

Question 7

Where does link reaction occur

Answer 7

Mitochondrial matrix

Question 8

Link reaction process

Answer 8

The pyruvate(3C) made in glycolysis is oxidised to acetate (2C)
—> decarboxylase remove carbon dioxide (1C)

NAD picks up hydrogen and becomes NADH —> dehydrogenase

Acetate(2C) the combines with coenzyme A in to produce acetylcoenzyme A (2C)

Question 9

Products of link reaction occurs twice for every glucose molecules

Answer 9

2x acetyl CoA
2x CO2 released
2 NADH

Question 10

Kreb cycle process

Answer 10

1) acetyl coenzyme A (product from link reaction) is combined with 4C molecules

2) 6C molecule undergoes oxidation as hydrogen atoms reduce 3x NAD and 1x FAD

3) two molecules of CO2 are released

4) phosphorylation of ADP produces ATP

Question 11

Kreb cycle input

Answer 11

2x acetyl coenzyme A
6x NAD
2x FAD
2x ADP

Question 12

Kreb cycle output

Answer 12

4x CO2
6X NADH
2X FADH2
2x ATP

Question 13

Electron transport chain process

Answer 13

1) hydrogen atoms are donated by NADH and FADH2 from kreb
—> hydrogen atoms splits protons and electrons

2) high energy electron enters the ETC and release energy as they move through ETC

3)the energy released transport protons across the inner mitochondrial membrane from the matrix into the inter membrane space

4) a concentration gradient of proton is established between the inter membrane space and the matrix

5) chemiosmosis occurs - diffusion/net movement of protons down the electrochemical gradient through ATP synthase the proton return to the matrix via facilitated diffusion through the channel enzyme ATP synthase

6)movement of protons down their concentration gradient provide energy for for ATP synthasis
—> to bring ADP + Pi = ATP

7) oxygen acts as the ‘final electron acceptor’ and combines with proton and electron at the end of ETC to form H2O

Question 14

Describe the role of the H+ gradient in making ATP

Answer 14

• H+ are more concentrated intermembranal space compared to the matrix into the intermembranal space by protein in the inner membrane of mitochondria
• H+ travel down their electrochemical gradient via the ATP synthase channel

-movement of H+ provides energy for the phosphorylation of ADP to form ATP

Question 15

Electron transport chain input

Answer 15

10x NADH
2X FADH2
6X O2
~ 36X ADP

Question 16

Electron transport chain output

Answer 16

10x NAD
2X FAD
6X H2O
~ 36X ATP

Question 17

Process of glycolysis

Answer 17

1) phosphorylation
- glucose is phosphorylation to glucose phosphate using ATP (which gets converted into ADP)
- glucose phosphate is then phosphorylation to hexose biphosphate using another ATP molecules
-the or biphosphate is the hydrolysis into 2 molecules of triose phosphate

OXIDATION
-2 triose phosphate are oxidised forming 2 molecules of pyruvate
-NAD collects 2H+ ions forming 2 NADH
- 4 ATP are produced, but 2 were used up in phosphorylation so there is a net gain 2 ATP in glycolysis

Question 18

Lactate fermentation animals formula

Answer 18

Pyruvate —> lactate —> glucose

Question 19

Anaerobic respiration in mammals

Answer 19

Glucose —> lactic acid
C6H12O6 —> 2C3H6O3

Question 20

Anaerobic respiration in plants and fungi

Answer 20

C6H12O6 —> 2C2H5OH + 2CO2
Glucose —> ethanol + carbon dioxide

Question 21

Anaerobic respiration consequences
Little or no oxygen

Answer 21

There is no final acceptor of electron from the ETC
Electron transport chain stops functioning
No more ATP is produced via oxidative phosphorylation
NADH and FAH2 aren’t oxidised by an electron carrier
No oxidised NAD and FAD are available for dehydrogenation in the Kreb cycle
The Kreb cycle stops
Link reaction stops

Question 22

Advantage of lactate

Answer 22

Can survive temporarily shoRage of oxygen

Used in strenuous exercise when the oxygen supply doesn’t match the demand

Question 23

How does pyruvate form lactate

Answer 23

Each pyruvate molecules takes two hydrogen from NADH oxidising to NAD to form lactate
Pyruvate is reduced to lactate by enzyme lactate dehydrogenase

Pyruvate + NADH = lactate + NAD

Question 24

Production of lactate

Answer 24

Once oxygen is available again

The lactate can be oxidised back into pyruvate

This can be further oxidised to release energy or converted into glycogen

Question 25

How does lactate effect in muscle

Answer 25

Lactate caused cramp and muscle fatigue if left in the muscle tissue

Lactate is an acid, so changes the pH

pH changes effect the enzyme

Muscle has some tolerance to lactate but it still need to be removed by the blood taken to the liver and converted into glycogen

Lactate is carried to the liver in blood
Converted back to pyruvate and respires in the liver cells
Oxygen is needed to oxidise the pyruvate made from the accumulated lactate

Question 26

.

Question 27

How to make ethanol

Answer 27

Each pyruvate molecules lose a molecule of carbon dioxide (decarboxylated) to ethanal by pyruvate decarboxylase

NADH transfer H to ethanal to form ethanol alcohol dehydrogenase

Question 28

Processing lactate

Answer 28

After lactate is produced:
-oxidised back to pyruvate which is then channelled into the Kreb cycle for ATP production
-can be converted into glucose by the liver cell for use during respiration or for storage

Oxidation of lactate back to pyruvate needs oxygen
-this extra oxygen is referred as oxygen debt
—> breathe deeper and faster after exercise