Brainscape's Knowledge GenomeTM

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


See full index

BIOLOGY > Respiration 5.2 > Flashcards

Respiration 5.2 Flashcards

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

How does 2x pyruvate from glycolysis enter the mitochondria?

A

Via active transport

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

Describe the process of glycolysis

A

• Phosphorylation of glucose using energy from ATP;
• Oxidation of triose phosphate to pyruvate;
• Net gain of (+2) ATP;
• NAD reduced

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

Describe how oxidation takes place in glycolysis and in the Krebs cycle.

A

• Dehydrogenation (removal of H);
• by enzymes/dehydrogenases;
• NAD carrier is reduced;
• FAD carrier used in Krebs cycle

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

Water is a waste product of aerobic respiration. Describe how water is formed at the end of aerobic respiration (2)

A

• Oxygen is final/terminal electron acceptor;
• Combines with electrons and protons to form water

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

Explain how the amount of ATP is increased by reactions occurring inside a mitochondrion

A

• oxidation of pyruvate (removes e- and H+)
• Acetyl Co-enzyme A / 6C compound
• Substrate level phosphorylation of ATP (in Krebs cycle);
• Production of REDUCED NAD + FAD;
• in matrix of mitochondria;
• electrons fed into electron transport chain;
• through series of redox reactions releasing energy;
• Protons move into intermembrane space;
• ADP + Pi by ATP synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the events of oxidative phosphorylation
OR
Describe the roles of the co-enzymes and carrier proteins in the synthesis of ATP

A

• NAD/FAD reduced (H+)
• H+ ions/electrons transferred from coenzyme to coenzyme / carrier to carrier (ETC on cristae of inner membrane);
• energy released through series of redox reactions;
• energy released used to pump H+ into intermembrane space forming an electro-chemical gradient;
• Protons flow back through ATP synthase to produce ATP from ADP + Pi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

I’m many mammals ‘uncoupling proteins’ help to maintain a constant body temperature during hibernation.
Suggest and explain how (2)

A
  1. Allow passage of protons/H+
  2. (Energy) released as heat.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

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

A

• Larger surface area for electron carrier system / MORE oxidative phosphorylation;
• provide MORE ATP / energy for contraction

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

Give two reasons why the respirometer was left for 10 minutes when it was first placed in the water bath (3)

A
  1. Equilibrium reached;
  2. Allow for expansion (gases/liquids) / pressure change in apparatus;
  3. Allow respiration rate of seeds to stabilise.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain why a log scale is used to record the number of cells/bacteria (2)

A
  1. Large range/difference/increase in numbers;
  2. Accept reference to exponential (increase)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain why converting pyruvate to lactate allows the continued production of ATP by anaerobic respiration (2)

A
  1. Regenerates NAD / Oxidises reduced NAD;
  2. (So) glycolysis continues;
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Malonate inhibits a reaction in the Krebs cycle.
Explain why malonate would decrease the uptake of oxygen in a respiring cell (2)

A
  1. Less/no reduced NAD/coenzymes OR Fewer/no hydrogens/electrons removed (and passed to electron transfer chain);
  2. Oxygen is the final/terminal electron acceptor;
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name the 4 stages in respiration and where they occur

A

Glycolysis: cytoplasm
Link reaction: mitochondrial matrix
Krebs cycle: mitochondrial matrix
Oxidative phosphorylation via electron transport chain: membrane of cristae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Outline the stages of glycolysis

A
  1. glucose is phosphorylated to glucose phosphate by 2x ATP
  2. glucose phosphate splits into 2x triose phosphate
    (ТР)
  3. 2x TP is oxidised to 2x pyruvate
    Net gain of 2x reduced NAD & 2x ATP per glucose.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does pyruvate from glycolysis enter the mitochondria?

A

via active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens during the link reaction?

A
  1. Oxidation of pyruvate to acetate.
    Per pyruvate molecule: net gain of 1xCO. (decarboxylation) & 2H atoms (used to reduce 1xNAD).
  2. Acetate combines with coenzyme A (CoA) to form acetylcoenzyme A.
17
Q

Give a summary equation for the link reaction

A

pyruvate + NAD + CoA —> acetyl CoA + reduced NAD + CO,

18
Q

What happens in the Krebs cycle?

A

series of redox reactions produces:
• ATP by substrate-level phosphorylation.
• Reduced coenzymes.
• CO, from decarboxylation.

19
Q

What is the electron transfer chain? (ETC) (2)

A
  1. Series of carrier proteins embedded in membrane of the cristae of mitochondria.
  2. Produces ATP through oxidative phosphorylation via chemiosmosis during aerobic respiration.
20
Q

What happens in the electron transport chain? (ETC) (3)

A
  1. Electrons released from reduced NAD & FAD undergo successive redox reactions.
  2. The energy released is coupled to maintaining proton gradient or released as heat.
  3. Oxygen acts as final electron acceptor.
21
Q

How is a proton concentration gradient established during chemiosmosis in aerobic respiration?

A

Some energy released from the ETC is coupled to the active transport of H* ions (protons) from the mitochondrial matrix into the intermembrane space.

22
Q

How does chemiosmosis produce ATP during aerobic respiration? (3)

A
  1. H* ions (protons) move down their concentration gradient from the intermembrane space into the mitochondrial matrix
  2. via the channel protein ATP synthase.
  3. ATP synthase catalyses ADP + Pi -> ATP.
23
Q

State the role of oxygen in aerobic respiration.

A

Final electron acceptor in electron transfer chain.
(produces water as a byproduct)

24
Q

What is the benefit of an electron transfer chain rather than a single reaction? (2)

A

• energy is released gradually
• less energy is released as heat

25
Q

Name 2 types of molecule that can be used as alternative respiratory substrates

A

• (amino acids from) proteins
• (glycerol and fatty acids from) lipids

26
Q

How can lipids act as an alternative respiratory substrate?

A

lipid -> glycerol + fatty acids

  1. Phosphorylation of glycerol -› TP for glycolysis.
  2. Fatty acid -> acetate.
    a) acetate enters link reaction.
    b) H atoms produced for oxidative phosphorylation.
27
Q

How can amino acids act as an alternative respiratory substrate?

A

Deamination produces:
1. 3C compounds -> pyruvate for link reaction.
2. 4C/ 5C compounds -> intermediates in
Krebs cycle.

28
Q

Name the stages in respiration that produce ATP by substrate-level phosphorylation (2)

A

• Glycolysis (anaerobic)
• Krebs cycle (aerobic)

29
Q

What happens during anaerobic respiration in animals? (3)

A

• Only glycolysis continues
• Pyruvate acts as hydrogen acceptor (NADH + pyruvate)
Produces —>
• oxidised NAD (for further glycolysis) +
lactate

30
Q

What happens to the lactate produced in anaerobic respiration? (2)

A

• Transported to liver via bloodstream, where it is oxidised to pyruvate.
• Can enter link reaction in liver cells or be converted to glycogen.

31
Q

What is the advantage of producing ethanol/lactate during anaerobic respiration?

A

• Converts reduced NAD back into NAD so glycolysis can continue.

32
Q

What is the disadvantage of producing ethanol during anaerobic respiration?

A

• Cells die when ethanol concentration is above 12%.
• Ethanol dissolves cell membranes.

33
Q

What is the disadvantage of producing lactate during anaerobic respiration?

A

• Acidic, so decreases pH.
• Results in muscle fatigue.

34
Q

Compare aerobic and anaerobic respiration.

A

• Both involve glycolysis
• Both require NAD
• Both produce ATP

35
Q

Contrast aerobic and anaerobic respiration.

A

Aerobic:
• Produces ATP by substrate-level phosphorylation AND oxidative phosphorylation
• produces much more ATP
• does not produce ethanol or lactate

Anaerobic:
• Substrate-level phosphorylation
• Produces fewer ATP (only 2 from glycolysis)
• produces ethanol/lactate

36
Q

Suggest how a student could investigate the effect of a named variable on the rate of respiration of a single-celled organism.

A
  1. Use respirometer (pressure changes in boiling tube cause a drop of coloured liquid to move).
  2. Use a dye as the terminal electron acceptor for the ETC
37
Q

What is the purpose of sodium hydroxide solution in a respirometer set up to measure the rate of aerobic respiration?

A

Absorbs CO, so that there is a net decrease in pressure as O, is consumed.

38
Q

How could a student calculate the rate of respiration using a respirometer?

A

• Volume of O2 produced or CO, consumed/ time x mass of sample
• Volume = distance moved by coloured drop x (0.5 x capillary tube diameter)2 x Tr

BIOLOGY (28 decks)

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