3.5.2 Respiration (Unit 5 Energy Transfers) Flashcards
1
Q
Identify the missing labels.
A
2
Q
Identify the missing label.
A
3
Q
Identify the missing labels.
A
4
Q
Identify the missing labels.
A
5
Q
Where does the link reaction occur?
A
Mitochondria (matrix)
6
Q
Identify the missing label.
A
7
Q
What are the products of glycolysis?
A
2 x Pyruvate
2 x (Net) ATP
2 x NADH
8
Q
Identify the process shown in the diagram.
A
Krebs Cycle (citric acid cycle)
9
Q
Identify the missing label.
A
10
Q
Identify the missing label.
A
11
Q
Identify the process shown in the diagram.
A
The link reaction of aerobic respiration
12
Q
FAD is reduced to make…
A
FADH2 (reduced FAD)
13
Q
Where does the Krebs cycle (citric acid cycle) occur?
A
Mitochondria (matrix)
14
Q
Describe what happens in the link reaction.
A
Oxidation of pyruvate (with NAD) to remove hydrogena nd release CO2
Addition of Coenzyme A to produce AcetylCoA
15
Q
Identify the missing label.
A
16
Q
Identify the missing labels.
A
17
Q
Identify the missing label.
A
18
Q
Which Coenzymes are involved in aerobic respiration?
A
NAD
FAD
Coenzyme A
19
Q
Where does glycolysis occur?
A
Cytoplasm
20
Q
Identify the missing label.
A
21
Q
How many electrons do NAD and FAD accept when they are reduced
A
Both accept 2
22
Q
Identify the missing label.
A
23
Q
Identify the missing labels.
A
24
Q
Identify the missing label.
A
25
Identify the missing label.
26
NAD is reduced to produce...
NADH
27
Identify the missing label.
28
Glycolysis is the breakdown of 1 x ________ into 2x \_\_\_\_\_\_\_\_\_
Glycolysis is the breakdown of 1 x **_glucose_** into 2 x **_pyruvate_**
29
Identify the missing label.
30
Identify the missing label.
31
Identify the missing labels.
32
Identify the 4 stages of aerobic respiration.
1. Glycolysis
2. Link Reaciton
3. Krebs Cycle (citric acid cycle)
4. Oxidative Phosphorylation
33
Identify the missing label.
34
What is a coenzyme?
A moelcule that works alongside an enzyme (usually dehydrogenase) to carry out a chemical process.
35
Where precisely does oxidative phosphorylation occur?
Cristae (inner membrane) of mitochondria
36
Identify the process.
Glycolysis
37
Identify the missing labels.
38
Describe Glycolysis
In the cytoplasm
Phosphorylation of glucose using ATP to make it more reactive;
Lysis of the phosphorylated glucose intermediate to form Triose Phosphate
Oxidation from TP to pyruvate by losing H+ and e-
Net gain of 2 ATP;
NAD reduced/NADH formed
39
Describe the link reaction
In the mitochondrial matrix
Pyruvate is oxidised using coenzyme A
CO2 released
NAD is reduced
Acetyl CoA is formed
40
Describe the krebs cycle
Acetyl CoA reacts with a 4C acceptor molecule
The 6C intermediate is decarboxylated and oxidised, removing CO2 and reducing NAD
The resulting 5C intermediate is also decarboxylated and oxidised removing CO2 and reducing 2xNAD, reducing FAD and generating 1x ATP in a series of REDOX reactions.
Until the original 4C acceptor is formed again.
41
Describe oxidative phosphorylation
FADH and NADH are oxidised and lose e- and H+
The e- are passed from carrier protein to carrier protein in the mitochondria inner membrane in a series of redox reactions
This releases energy
The energy is used to pump H+ through the membrane into the inner membrane space building a chemiosmotic gradient
H+ moves back through the membrane through ATP synthase
ADP + Pi ATP
Oxygen is the terminal electron acceptor forming water
42
Why is oxygen so important to aerobic respiration.
It is the final electron acceptor.
H+ and electron transport would stop.
NAD and FAD cannot be resynthesised as NADH and FADH2 cannot give up their H+ and electrons.
43
The energy not harvested during the electron transport chain is lost as...
heat
44
The enzyme that catalyses the reaction of ADP + Pi --\> ATP is...
ATP synthase
45
Many mitochondria are present in metabolically active cells such as...
Muscle (contraction)
Liver (detoxification)
Epithelial cells (secretion)
46
The mitochondria of metabolically active cells have more densely packed cristae. How does this help these cells?
A greater surface area of inner membrane is provided which include the enzymes and proteins involved in oxidative phosphorylation.
47
Why is it more useful to release energy in stages via an electron transport chain rather than all at once in one single step?
The transfer of electrons down an energy gradient allows energy to be released in a more gradual way.
This minimises energy wasted as heat.
48
Why does the electron transport chain, krebs cycle and link reaction stop in the absence of oxygen?
Oxygen is the final electron acceptor in the ETC.
Electrons 'back up' along ETC.
NADH and FADH2 are unable to become oxidised.
NAD and FAD are not regenerated.
NAD and FAD (Krebs only) needed to oxidise substrates of Krebs and link reactions.
49
Which reaction is the only source of ATP in anaerobic conditions?
Glycolysis
50
Can glucose cross the mitochondrial membrane?
No - glycolysis breaks it down into pyruvate, which is then transported across the membrane.
51
What is the equation for anaerobic respiration in plants/microorganisms.
Pyruvate + NADH --\> Ethanol + CO2 + NAD
52
Which equation is shown below:
Pyruvate + NADH --\> Ethanol + CO2 + NAD
Anaerobic respiration in plants/bacteria
Pyruvate + NADH --\> Ethanol + CO2 + NAD
53
Describe anaerobic respiration in mammals
Pyruvate is reduced to lactate
NADH is oxidised during this process
This prevents NAD running out and allows ATP to continue being made in glycolysis
54
Describe anaerobic respiration in yeast
Pyruvate is reduced to ethanal then ethanol
NADH is oxidised during this process
CO2 is produced
This prevents NAD running out and allows ATP to continue being made in glycolysis
55
