Section 5: Chapter 12: Respiration

Question 1

What are the 4 stages of aerobic respiration?

Answer 1

Glycolysis.
Link reaction.
Krebs cycle.
Oxidative Phosphorylation.

Question 2

What are the end products of glycolysis?

Answer 2

2 ATP mols.
2 NADH mols.
2 Pyruvate mols.

Question 3

Why is glucose converted to phosphorylated glucose in glycolysis?

Answer 3

To make it more reactive.

Decrease activation energy.

Question 4

Draw the process of glycolysis.

Answer 4

Look in folder or desktop.
Should go Glucose → phosphorylated glucose → 2 TP → 2 Pyruvate.
Also show ATP and NAD and no. of carbons.

Question 5

Where does glycolysis take place?

Answer 5

Cytoplasm.

Question 6

Where does the link reaction take place?

Answer 6

Matrix.

Question 7

Where does the Krebs cycle take place?

Answer 7

Matrix.

Question 8

Where does oxidative phosphorylation take place?

Answer 8

Mitochondria.

Question 9

what is the name of the reaction taking place in the link reaction?

Answer 9

Oxidation.

Question 10

What are the products of the link reaction?

Answer 10

Acetyl CoA
NADH
CO2

Question 11

What is the name of the process that removes a carbon mol from pyruvate in the link reaction?

Answer 11

Decarboxylation.

Question 12

What is the name of the coenzyme used in the link reaction?

Answer 12

NAD (it’s reduced to NADH).

Question 13

Draw the link reaction.

Answer 13

In folder and desktop.

Pyruvate, acetyl, NAD, CO2, Acetyl CoA etc.

Question 14

Draw the Krebs cycle.

Answer 14

In folder and desktop.

Question 15

What are the products of the link reaction AND Krebs cycle?

Answer 15

4 NADH and 1 FADH (I think?).
1 mol of ATP.
3 mols of CO2.
REMEMBER THIS HAPPENS TWICE BECAUSE @ PYRUVATE MOLS.

Question 16

Explain the process of oxidative phosphorylation. (4 steps).

Answer 16

1) NADH and FADH donate electrons to electron transfer chain.
2) Electrons pass along chain, giving energy to H+ for AT.
3) H+ ions go from inter-membranal space back to matrix. Down chemiosmotic gradient. Through ATP synthase.
4) O2 is final electron acceptor in mitochondrial matrix. ½ O + 2H+ + 2e- → H2O.

Question 17

Draw oxidative phosphorylation.

Answer 17

In folder and desktop.

Question 18

How are lipids used as respiratory substances?

Answer 18

• Hydrolysed into glycerol and fatty acids.
• Glycerol - phosphorylated to TP.
• Fatty acids - broken down to 2C - then Acetyl CoA.
• Releases more than double energy than carbs.

Question 19

How are proteins used as respiratory substances?

Answer 19

• Hydrolysed to amino acids.
• Deamination (removing amine group).
• 3C’s are converted to pyruvate.
• 4C and 5C’s are used in Krebs cycle.

Question 20

What parts of respiration cannot happen without O2?

Answer 20

Krebs cycle.

Electron transfer chain / oxidative phosphorylation.

Question 21

How is glycolysis still able to work even without O2 (anaerobic respiration)?

Answer 21

Hydrogen immediately released so NADH can regenerate to NAD.

- Pyruvate accepts H+ from NADH.

Question 22

What is pyruvate turned into in anaerobic respiration in plants and yeast?

Answer 22

Ethanol, CO2 and oxidised NAD.

Question 23

What is pyruvate turned into in anaerobic respiration in animals?

Answer 23

Lactate and oxidised NAD.

Question 24

Why is anaerobic respiration advantageous to animals?

Answer 24

• Babies and baby mammals can survive in water straight after birth.
• In muscles to allow strenuous exercise.

Question 25

Why does lactate in humans have to be oxidised back into pyruvate asap?

Answer 25

It’s acidic so can cause pH changes and cramps.