Respiration

Question 1

Respiration definition.

Answer 1

The process that occurs in living cells and releases the energy stored in glucose

Question 2

Examples of uses of ATP?

Answer 2

Active and bulk transport
Protein synthesis
DNA replication
Cell division

Question 3

What are metabolic reactions?

Answer 3

Chemical reactions which take place inside living cells

Question 4

Difference between anabolic and catabolic reactions?

Answer 4

Anabolic large molecules are synthesised from smaller ones

Catabolic involves the breakdown of larger molecules to smaller ones

Question 5

Structure of ATP?

Answer 5

Adenine
5 carbon sugar
3 phosphate groups

Question 6

How does ATP release energy?

Answer 6

When it is hydrolysed to ADP

Question 7

Structure of Adenosine?

Answer 7

Adenine and ribose

Question 8

Difference between AMP and ADP?

Answer 8

AMP has 1 phosphate group, ADP has 2

Question 9

How much energy is released when ATP is hydrolysed?

Answer 9

30.5 kJ mol-1

Question 10

How much energy is released when ADP is hydrolysed?

Answer 10

30.5 kJ mol-1

Question 11

How much energy is released when AMP is hydrolysed?

Answer 11

13.8 kJ mol-1

Question 12

Glycolysis definition?

Answer 12

The first stage of respiration, a 10 stage metabolic pathway that converts glucose to pyruvate

Question 13

What are the 3 main stages of glycolysis?

Answer 13

Phosphorylation of glucose
Spitting of hexose biphosphate
Oxidation of triose phosphate

Question 14

What happens in the phosphorylation of glucose?

Answer 14

2 molecules of ATP are hydrolysed and the released phosphate group is added to hexose to form hexose monophosphate. ATP hydrolysed again to form hexose biphosphate

Question 15

Structure of hexose biphosphate

Answer 15

6 carbon compound

1 phosphate group at carbon 1 and another at carbon 6

Question 16

What is NAD?

Answer 16

A non protein molecule that helps dehydrogenase enzymes carry out oxidation reactions

Question 17

Structure of NAD?

Answer 17

Nicotinamide
Ribose
Adenine
2 phosphoryl groups

Question 18

How does NAD become reduced NAD?

Answer 18

By the nicotinamide accepting 2 hydrogen atoms

Question 19

What is hexose biphosphate split into?

Answer 19

Two 3 carbon molecules called triose phosphate

Each triose phosphate has a phosphate group attached

Question 20

What happens in the oxidation of triose phosphate?

Answer 20

Dehydrogenase enzymes remove hydrogen atoms from triose phosphate.

Question 21

Why are the 4 stages of respiration?

Answer 21

Glycolysis
The link reaction
Krebs cycle
Oxidative phosphorylation

Question 22

Which stage is anaerobic?

Answer 22

Glycolysis

Question 23

Products of glycolysis?

Answer 23

4 ATP- 2 net gain
2 reduced NAD
2 pyruvate molecules

Question 24

When is active transport used after glycolysis?

Answer 24

To transport pyruvate across the outer and inner mitochondrial membrane

Question 25

What happens in the mitochondrial matrix?

Answer 25

Link reaction | Krebs cycle

Question 26

What happens in the link reaction?

Answer 26

Pyruvate is decarboxylated and dehydrogenated

Question 27

What enzyme catalyses the link reaction?

Answer 27

Pyruvate dehydrogenase

Question 28

Is any ATP produced in the Link reaction?

Answer 28

No

Question 29

Product of the link reaction?

Answer 29

Acetyl co enzyme A

Question 30

How is acetyl CoA produced?

Answer 30

Carboxyl group removed from pyruvate Produces acetyl group Combines with Co enzyme

Question 31

Where do the hydrogen atoms removed from triose phosphate go?

Answer 31

The two molecules of NAD accepts the hydrogen atoms. This reduces NAD

Question 32

How to remember oxidation and reduction.

Answer 32

OILRIG Oxidation is lost Reduction is gained

Question 33

Role of NAD in glycolysis?

Answer 33

Aids dehydrogenase enzymes to remove hydrogen atoms from triose phosphate.

Question 34

Describe the shape of mitochondria?

Answer 34

Rod- shaped Diameter of 0.5-1 micrometer Length of 2-5 micrometers but up to 10

Question 35

How many membranes do mitochondria have?

Answer 35

2- inner and outer | Makes up the envelope

Question 36

What is the differences in the membranes of the mitochondria?

Answer 36

The outer membrane is smooth and the inner is folded into cristae Inner membrane is less permeable to small ions

Question 37

What is an advantage of cristae?

Answer 37

Gives a large surface area

Question 38

What is found in the inner membrane?

Answer 38

Proteins that transport electrons | Protein channels associated with ATP synthase enzyme

Question 39

What is the space between the membranes?

Answer 39

Intermembrane space

Question 40

Describe the mitochondrial matrix

Answer 40

Semi rigid, gel like and fluid filled

Question 41

What does the mitochondrial matrix contain?

Answer 41

Mitochondrial ribosomes Looped mitochondrial DNA Enzymes

Question 42

What takes place in the matrix?

Answer 42

Link reaction and krebs cycle

Question 43

Where does glycolysis take place?

Answer 43

In the cytoplasm

Question 44

What does the matrix contain for those processes?

Answer 44

Enzymes Molecules of NAD and FAD Oxaloacetate

Question 45

What is the Krebs cycle?

Answer 45

A series of enzyme catalysed reactions that oxidise the acetate from the link reaction

Question 46

Step 1 of Krebs cycle?

Answer 46

Acetyl group (2c) combines with oxaloacetate (4c) to form citrate (6c)

Question 47

Step 2 of Krebs cycle?

Answer 47

Citrate is decarboxylated and dehydrogenated producing a 5c. 2H, CO2 and reduced NAD is released.

Question 48

Step 3 of Krebs cycle?

Answer 48

Repeat it step 2 to produce a 4c. 2H, CO2 and reduced NAD is released

Question 49

Step 4 of Krebs cycle?

Answer 49

4c combines temporarily and is then released from Coenzyme A. Substrate phosphorylation occurs to release ATP.

Question 50

Step 5 of Krebs cycle?

Answer 50

4c is dehydrogenated. Reduced FAD released

Question 51

Step 6 of Krebs cycle?

Answer 51

Further dehydrogenation. 2H and reduced NAD.

Question 52

How is oxalocacetate regenerated?

Answer 52

By rearrangement of atoms in the 4c, catalysed by an isomerase enzyme.

Question 53

How much ATP is produced in the Krebs cyle?

Answer 53

For 1 molecule of glucose there are 2 turns of the Krebs cyle. So two molecules of ATP per glucose is produced.

Question 54

What is chemiosmosis?

Answer 54

The flow of protons, down their conc gradient through a channel associated with atp synthase

Question 55

What is oxidative phosphorylation?

Answer 55

The formation of ATP using energy released in the electron transport chain and in the presence of oxygen. The final stage in aerobic respiration

Question 56

Where do the protons come from?

Answer 56

When reduced FAD and reduced NAD deliver their hydrogen atoms to the electron transport chain. They then split into protons and electrons.

Question 57

What happens along the electron transport chain?

Answer 57

The electrons from the splitting of the hydrogen atom is passed along the electron carrier chain. As electrons are passed along the chain, some of their energy is used to pump the protons into the intermembane space.

Question 58

Where is the electron transport chain?

Answer 58

Embedded in the inner mitochondrial membrane (cristae)

Question 59

What does each electron carrier have?

Answer 59

An iron ion at it's core

Question 60

How is the proton gradient caused?

Answer 60

The accumulation of protons cause a proton gradient.

Question 61

What does the proton gradient generate?

Answer 61

A chemiosmotic potential also known as a proton motive force (pmf)

Question 62

How is ATP generates from pmf?

Answer 62

The inner membrane is impermeable to protons and the outer membrane has low permeability to protons. Protons can diffuse through a protein channel associated with ATP synthase enzymes.