Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AQA A Level Biology > 3.3.3 Respiration > Flashcards

3.3.3 Respiration Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What do both aerobic and anaerobic respiration start with?

A

Glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does glycolysis occur?

A

Happens in cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Is glycolysis are anaerobic or aerobic process?

A

Anaerobic process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the 2 stages in glycolysis

A
  1. Phosphorylation
  2. Oxidation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Glycolysis

Describe what happens in phosphorylation

A
  1. Glucose is phosphorylated using phosphate from a molecule of ATP
    • Creates 1 molecule of glucose phosphate and 1 molecule of ADP
  2. ATP is then used to add another phosphate = hexose bisphosphate
  3. Hexose bisphosphate is splits into 2 molecules of TP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Glycolysis

Describe what happens in oxidation

A
  1. TP is oxidised (loses H) = 2 molecules of pyruvate
  2. NAD collects H+ ions = 2 reduced NAD
  3. 4 ATP produced, but 2 used up in stage 1 ∴ net gain of 2 ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens to the products of glycolysis in aerobic respiration?

A
  • 2 molecules of reduced NAD go to oxidative phosphorylation
  • 2 pyruvate molecules are actively transported into matrix of mitochondria for link reaction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Anaerobic Respiration

Pyruvate is converted into ___ in plants and yeast

A

Ethanol

(Using reduced NAD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Anaerobic Respiration

Pyruvate is converted into ___ in animal cells and some bacteria

A

Lactate

(Using reduced NAD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Illustrate Alcoholic Fermentation

(i.e. write equation)

A

Reduced NAD reduces/donate H ions to pyruvate to ethanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Illustrate Lactate Fermentation

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name the 4 main stages in aerobic respiration

A
  1. Glycolysis
  2. Link Reaction
  3. Krebs Cycle
  4. Oxidative Phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the link reaction

A
  1. Pyruvate is decarboxylated
    • (1 C is removed in form of CO₂)
  2. Pyruvate is oxidised to form acetate
    • & NAD is reduced to form reduced NAD
  3. Acetate is combined with coenzyme A (CoA) to form acetyl coenzyme (acetyl CoA)
  4. No ATP produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

2 pyruvate molecules are made for every glucose molecule that enters glycolysis. This means that the ____ _____ and _____ _____ happens _____ for every glucose molecule.

A

2 pyruvate molecules are made for every glucose molecule that enters glycolysis. This means that the link reaction and Krebs cycle happens twice for every glucose molecule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

After Link Reaction

For each glucose molecule, state the quantity of each product and where they go

A
  1. 2 molecules of acetyl CoA go into the Krebs cycle
  2. 2 CO₂ molecules are released as waste product
  3. 2 molecules of reduced NAD are formed and go to oxidative phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Krebs cycle Involves a series of ________ reactions

A

oxidation-reduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where does the Krebs cycle takes place?

A

In matrix of mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Krebs cycle happens once for every ______ molecule & goes round 2x for every ______ molecule

A

Krebs cycle happens once for every pyruvate molecule & goes round 2x for every glucose molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the Krebs cycle

A
  1. Acetyl CoA combines with 4C to form 6C
    1. CoA A goes back to link reaction to be used again
  2. 6C → 5C
    1. Decarboxylation occurs
    2. Dehydrogenation occurs
    3. H is used to NAD → reduced NAD
  3. 5C → 4C
    1. Decarboxylation and dehydrogenation occur, produced 1x reduced FAD & 2x reduced NAD
    2. ATP is produced by direct transfer of phosphate group from intermediate compound to ADP
      1. Called substrate-level phosphorylation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Define oxidative phosphorylation

A
  • Process where energy carried by electrons, from reduced coenzymes (reduced NAD and reduced FAD), is used to make ATP
  • Involves electron transport chain and chemiosmosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe Oxidative Phosphorylation

A
  1. Reduced NAD → NAD & reduced FAD → FAD = releases H
    • H atoms split into protons and e−
  2. e− move down electron transport chain, losing energy at each carrier
  3. Energy is used to pump protons from mitochondrial matrix into intermembrane space
  4. Conc. of protons is now higher in intermembrane space than in mitochondrial matrix
    • Forms electrochemical gradient
  5. Protons move down electrochemical gradient into mitochondrial matrix via ATP synthase
    • Movement drives synthesis of ATP from ADP and P¡
  6. In mitochondrial matrix, at end of transport chain, protons, electrons and O₂ (from blood) combine to form water
    • O₂ = final electron acceptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

____ ATP are made from each reduced NAD and ___ ATP are made from each reduced FAD

A

2.5 ATP are made from each reduced NAD and 1.5 ATP are made from each reduced FAD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What do mitochondrial diseases affect?

A
  • Affect functioning of mitochondria
    • Affect how proteins involved in oxidative phosphorylation or Krebs cycle function = reducing ATP production
26
Q

Describe the effect of mitochondrial diseases

A
  1. May cause anaerobic respiration to increase, to try and make up some of the ATP shortage
  2. = lots of lactate being produced, which can cause muscle fatigue and weakness
  3. Some lactate will diffuse into bloodstream = high lactate concentrations in blood
27
Q

Describe how proteins can be used as respiratory substrates

A
  1. Amino acids used as respiratory substances
  2. Those not used for protein synthesis are deaminated in liver cells
  3. Remainder of molecule can be converted into glycogen or fat
  4. If there’s not enough carbohydrates, muscle proteins can be hydrolysed to amino acids
28
Q

Describe how glycerol can be used as a respiratory substrate

A

Glycerol oxidised and phosphorylated into TP and then enters end of glycolysis

29
Q

Describe how fatty acids can be used as a respiratory substrate

A

Fatty acids are broken down by process known as beta oxidation to produce acetyl CoA when then enters the Krebs cycle

30
Q

What is produced a lot in beta oxidation?

A

Large amounts of FADH2 and NADH

31
Q

Fatty acids can only be broken down _______

A

aerobically

32
Q

Why can fatty acids only be broken down aerobically?

A

∵ oxygen will be required as final electron acceptor

33
Q

Why do red blood cells only respire glucose?

A

Have no mitochondria - only respire anaerobically

(lipids and proteins require aerobic conditions)

34
Q

What is the respiratory quotient

A

Is the ratio of CO₂ to O₂ in relation to a given respiratory substrate

35
Q

Describe how RQ values can be determined experimentally

A

By measuring O₂ consumption and CO₂ production using a respirometer

36
Q

By calculating RQ value, what can you find out?

A
  • Substrates being used in respiration by an organism
  • Type of respiration being carried out can be deduced
37
Q

State the equation for calculating RQ

A

RQ = moles of CO₂ given out
—————————————
Moles of O₂ taken in

38
Q

Work out the RQ for glucose

A

RQ = 6CO2
———
6O2

oxidised and phosphorylated RQ = 1

39
Q

RQ < 1, it’s a ____ or ___

A

protein or lipid

40
Q

The production of ethanol or lactate regenerates oxidised NAD. Why is this good?

A
  • Means glycolysis can continue when there isn’t much oxygen around
  • ∴ small amount of ATP can be produced to keep some biological processes going
41
Q

Describe how you would investigate the effect of temperature on the rate of respiration of yeast

A
  1. Set water bath at 35°C
  2. Label 5 test tubes
  3. Shake yeast and glucose mixture
  4. Add 2 cm3 of yeast and glucose mixture to each test tube
  5. Place all test tubes in water bath and wait until their contents reach 35°C
  6. Add 1 cm3 of methylene blue to test tube 1
  7. Shake test tube for 10s
  8. Time how long it takes for solution to change from blue to colourless
  9. Repeat steps 6-8 for other 4 tubes
  10. Repeat steps 1-9, but use temperatures of 40°C, 45°C, 50°C, 55°C
42
Q

Explain why methylene blue changes from blue to colourless

A
  1. During aerobic respiration, transport of electrons is linked to synthesis of ATP
  2. Electrons are taken up by methylene blue
  3. When methylene blue is reduced, changes from blue to colourless
43
Q

What is a respirometer is used for?

A

Used to indicate rate of aerobic respiration by measuring amount of oxygen consumed by organism in one period of time

44
Q

Respirometer

What happens to the volume of air in test tube with e.g. woodlice & why?

A
  • Volume of air decreases due to oxygen consumed during respiration
  • All CO₂ absorbed by potassium hydroxide
45
Q

Respirometer

What happens when the volume of air in the test tube with e.g. woodlice decreases (as oxygen is taken up)?

A
  • Decrease pressure in test tube
  • Causes coloured fluid in capillary tube of manometer to move toward it
46
Q

Describe what happens to reduced NAD produced in Krebs cycle (3)

A
  • Enters mitochondria
  • NADH → oxidised to NAD
  • Used to produce ATP
47
Q

Describe the part played by the inner membrane of mitochondrion in producing ATP (3)

A
  • electrons transferred down electron transport chain
  • provides energy to take protons into intermembrane
  • protons pass through membrane, ATP synthase
48
Q

Glucose _______ ______ the mitochondrial _______

A

Glucose cannot cross the mitochondrial membrane

49
Q

Human synthesise more than their body mass of ATP each day. Explain why it is necessary for them to synthesise such a large amount of ATP. (2)

A
  • ATP cannot be stored/is an immediate source of energy
  • ATP only releases a small amount of energy at a time
50
Q

What measurements should the student have taken to calculate the rate of aerobic respiration in mm3 of oxygen g-1 h-1 (3)

A
  • Distance (drop moves) and time
  • Mass of organism
  • Diameter of tube
51
Q

Draw Glycolysis. Include no. of carbon.

A
52
Q

Draw the Link Reaction. Include no. of carbon.

A
53
Q

Draw the Krebs Cycle. Include no. of carbon.

A
54
Q

The mitochondria in muscles contain many cristae. Explain the advantage of this. (2)

A
  • Larger surface area for oxidative phosphorylation
  • Provide ATP / energy for contraction
55
Q

Explain why cells gain more energy from lipid than from carbohydrate (3)

A
  • More H in lipid
  • More protons so more reduced FAD/NAD/(more protons) move across inner mitochondrial membrane
  • More ATP produced
  • More electrons moving down ETC
56
Q

Explain why less energy is released in anaerobic respiration (1)

A

Glucose only partly broken down/broken down to lactate

57
Q

At the end of a sprint race, a runner continues to breathe rapidly for some time. Explain the advantage of this. (2)

A
  • Lactate built up
  • Oxygen used to break down lactate/convert it back to pyruvate
58
Q

Respiration Experiment

State how temperature could be controlled

A

Using a water bath

59
Q

Respiration Experiment

State how pH could be controlled

A

Using a buffer solution

60
Q

Explain why the scientist adds pyruvate rather than glucose to the isolated mitochondria (2)

A
  • Glycolysis occurs in cytoplasm
  • Glycolsis produces pyruvate
61
Q

Explain why muscles become fatigued when insufficient oxygen is available (2)

A
  • build up / increased concentration of lactate lowers pH / increases H / increases acidity
  • enzymes / named protein inhibited(not denatured)

AQA A Level Biology (41 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions