Comp 1

Question 1

What are the 4 stages of aerobic respiration

Answer 1

Glycolysis
The link reaction
The Krebs cycle
The electron transport chain

Question 2

What are the 3 net products of glycolysis

Answer 2

2 Pyruvate
2 ATP
2 Reduced NAD

Question 3

What are the 5 steps for glycolysis

Answer 3

1. Glucose molecule is phosphorylated by adding 2 phosphate groups via 2 molecules of atp, producing glucose diphosphate
2. The glucose diphosphate splits into 2 molecules of triose phosphate
3. The 2 TP is dehydrogenated, oxidising them into pyruvate
4. The hydrogen atoms are transferred into NAD making reduced NAD
5. These steps are enough to synthesis 4 molecules of ATP by substrate level phosphorylation

Question 4

What happens to the 2 products of ATP in glycolysis

Answer 4

Is used by the cell

Question 5

What happens to the 2 products of reduced NAD in glycolysis

Answer 5

Transported indirectly by a pathway into the inner mitochondrial membrane to make more ATP

Question 6

What happens to the products of 2 pyruvate in glycolysis

Answer 6

Are actively transported into the mitochondrial matrix in aerobic conditions to contue to be broken down

Question 7

Where does the link reaction take place In

Answer 7

Mitochondrial matrix

Question 8

What are the 3 steps for the link reaction in aerobic respiration

Answer 8

1. Pyruvate enters the mitochondrial matrix by diffusion
2. Pyruvate is dehydrogenated so hydrogen is released and accepted by NAD to form reduced NAD
3. Pyruvate is decarboxylated so a 2 carbon acetyl group remains and combines with coenzyme A to form acetyl coenzyme A which enters the Krebs cycle

Question 9

Where does the Krebs cycle take place

Answer 9

Mitochondrial matrix

Question 10

What 3 things does the Krebs cycle generate of

Answer 10

Carbon dioxide
Reduced NAD
FAD

Question 11

What are the 4 products of krebs cycle

Answer 11

1 ATP produced by substrate level phosphorylation

3 reduced NAD

1 reduced FAD

2 carbon dioxide

Question 12

How many times does decarboxylation happen in Krebs cycle

Answer 12

2 Times

Question 13

How many times does dehydrogenation happen in Krebs cycle

Answer 13

4 times

Question 14

What are the 4 steps of Krebs cycle

Answer 14

1. Acetyl CoA enters by combining 4 carbon acid to form a 6 carbon compound and CoA is regenerated
2. 6 carbon acid is dehydrogenated making reduced NAD and decarboxylated to make carbon dioxide and 5 carbon acid
3. 5 carbon acid is dehydrogenated to make reduced NAD and FAD and decarboxylated to make carbon dioxide and regenerate 4 carbon acid
4. 4 carbon acid can be combined with more AcCoA and repeat cycle

Question 15

Where is the electron transport chain located on

Answer 15

Cristae of inner mitochondria membrane

Question 16

Define photolysis

Answer 16

Splitting of water molecules by light producing hydrogen ions, electrons and oxygen

Question 17

Why is ATP described as a universal energy currency

Answer 17

Used in all cells to drive their reactions

Question 18

What are 3 types of phosphorylation

Answer 18

Oxidative phosphorylation
Photo phosphorylation
Substrate level phosphorylation

Question 19

Describe oxidative phosphorylation

Answer 19

The energy for making ATP comes from oxidation reduction reactions and is released in the transfer of electrons along a chain of electron carrier molecules

Question 20

Where does photo phosphorylation occur on

Answer 20

the thylakoid membrane of the chloroplasts in light dependent stages of photosynthesis

Question 21

Where does oxidative phosphorylation occur in

Answer 21

the inner membrane of mitochondria in aerobic respiration

Question 22

How are hydrogen ions transported through ETC in oxidative phosphorylation

Answer 22

Via active transport

Question 23

What do the free electrons, oxygen and hydrogen ions do in oxidative phosphorylation

Answer 23

Join to form water

Question 24

What happens in lactate fermentation

Answer 24

Pyruvate is used to make lactate acid by enzyme lactate dehydrogenase, which produces a molecule of NAD from reduced NAD

Question 25

What does the lactate do after from being converted from pyruvate

Answer 25

Is converted to glucose via oxygen debt by oxygen in the liver

Question 26

What is the net loss of ATP in lactate fermentation

Answer 26

4

Question 27

Why is lactate fermentation not sustainable

Answer 27

Has a net loss of 4 ATP

Question 28

What happens In alcohol fermentation

Answer 28

Pyruvate is used to make Ethanal by enzyme pyruvate decarboxylase and then that is converted to ethanol by the enzyme ethanol dehydrogenase

Question 29

Why is beer fizzy

Answer 29

The Carbon dioxide is dissolved in the liquid ans isn’t escaped

Question 30

Why is wine flat

Answer 30

The carbon dioxide is escaped

Question 31

Why is wine not toxic

Answer 31

The yeast is killed by the ethanol

Question 32

What does bread rise from

Answer 32

The carbon dioxide from the yeast

Question 33

Why is bread not alcohol

Answer 33

Ethanol is dissolved when put in high temperatures

Question 34

Name 2 respiratory substrates

Answer 34

Triglyceride Protiens

Question 35

Describe hoe reduced FAD and reduced NAD is used to create an electrochemical gradient

Answer 35

The reduced FAD and NAD passes electrons to the ETC The high energy electrons is used to power the proton pumps on the cristae This pumps the hydrogen ions into the inner membrane space and relates a concentration gradient

Question 36

Describe what happens to a molecule of carbon dioxide when it is removed in humans

Answer 36

It is diffused out of the mitochondria and is carried by hydrogen carbonate ions. Then it is breathed out

Question 37

Explain the reasons for reduced NAD being required to maintain a proton gradient

Answer 37

Supplies protons and brings high energy for the proton pumps which actively transports hydrogen ions into the inner membrane space