Respiration Flashcards
(92 cards)
1
Q
What is respiration?
A
The process by which complex organic molecules, such as carbohydrates, are broken down to release energy which is then used to make ATP
2
Q
Where does aerobic respiration mainly occur?
A
Mitochondria
3
Q
Where does anaerobic respiration occur?
A
Cytoplasm
4
Q
What requires energy?
A
Anabolic reactions
Movement
Active transport
5
Q
What are the 4 stages of respiration?
A
Glycolysis
Link reaction
Kreb’s cycle
Oxidative phosphorylation
6
Q
Where does glycolysis occur?
A
Cytoplasm
7
Q
Where does the link reaction occur?
A
Matrix
8
Q
Where does the Kreb’s cycle occur?
A
Matrix
9
Q
Where does oxidative phosphorylation occur?
A
Inner membrane
10
Q
What gets oxidised in respiration?
A
Glucose (goes to carbon dioxide)
11
Q
What gets reduced in respiration?
A
Oxygen (goes to water)
12
Q
What enzymes are used in respiration?
A
Dehydrogenase enzymes
13
Q
What do dehydrogenase enzymes do?
A
Remove hydrogen
14
Q
What coenzymes are used in respiration?
A
NAD
FAD
CoA
(ATP)
15
Q
What is the diameter of a mitochondria?
A
0.5-1 micrometers
16
Q
What is the length of a mitochondria?
A
2-5 micrometers
17
Q
What does glycolysis mean?
A
Splitting carbohydrates
18
Q
What type of respiration does glycolysis happen in?
A
Aerobic and anaerobic as it doesn’t require oxygen
19
Q
What organisms do glycolysis?
A
Eukaryotes and prokaryotes
20
Q
What does glycolysis form?
A
2 molecules of pyruvate from one glucose molecule
2 ATP
2 reduced FAD
21
Q
What happens to glucose in the first step of glycolysis?
A
2 ATP is used (dephosphorylation) to form hexose bisphosphate
22
Q
What happens to hexose bisphosphate is glycolysis?
A
Lysis as it is unstable
Forms 2 triose phosphates
23
Q
What happens to the 2 triose phosphates in glycolysis?
A
Gets phosphorylated using phosphate in the cytoplasm to form 2 triose bisphosphate
24
Q
What happens to the 2 triose bisphosphate in glycolysis?
A
Phosphates are used to make 4 ATP
Uses hydrogen to reduce 2 NAD
Forms 2 pyruvate molecules
25
What is dephosphorylated in glycolysis?
ATP, Triose bisphosphate
26
What is lysed in glycolysis?
Hexose bisphosphate
27
What is dehydrogenated in glycolysis?
Triose bisphosphate
28
What is reduced in glycolysis?
NAD
29
What is oxidised in glycolysis?
Triose bisphosphate
30
What is phosphorylated in glycolysis?
ADP, Glucose, Triose phosphate
31
What is a coenzyme?
Something that helps an enzyme to function
| In respiration they are required for dehydrogenase enzymes to remove the hydrogen
32
What is substrate-level phosphorylation?
Using phosphate that is removed from an organic molecule to produce ATP from ADP+Pi
33
What is another name for the link reaction?
Oxidative decarboxylation
34
How does pyruvate enter the mitochondrial matrix?
Through membrane proteins by active transport. requires ATP produced by aerobic respiration
35
What is the name given to the process that removes carbon dioxide?
Decarboxylation
36
What is removed from pyruvate in the link reaction?
Carbon dioxide
Hydrogen (in order to reduce 2 NAD)
This forms acetate
37
What is joined to acetate in the link reaction?
Coenzyme A
| This forms Acetyl CoA
38
What are the organic and inorganic products formed in the link reaction?
Inorganic - Carbon dioxide
| Organic - Acetyl CoA
39
Why does glycolysis occur in the cytoplasm instead of in the mitochondria?
Glycolysis came before mitochondria
| Mitochondria only came later - after endosymbiosis
40
How does a multi-enzyme complex increase the efficiency in a metabolic pathway?
Requires lots of different enzymes as there are lots of different substrates
All enzymes are closer together so speeds up the process (less time to get from one enzyme to another)
41
How many molecules of ATP are produced in the link reaction per glucose?
0
42
How many molecules of reduced NAD are produced in the link reaction per glucose?
2 (1 from each pyruvate)
43
How many molecules of carbon dioxide are produced in the link reaction per glucose?
2 (1 from each pyruvate)
44
How do you remember the Kreb's cycle?
DeNA DeNA A FANA
45
What does DeNA DeNA A FANA mean?
```
Decarboxylation
NAD is reduced
Decarboxylation
NAD is reduced
ATP produced
FAD reduced
NAD reduced
```
46
What does the Kreb's cycle start with?
Oxaloacetate + Acetyl CoA
47
What occurs to allow reduction to occur in the Kreb's cycle?
Dehydrogenation (removed H and adds it to NAD/FAD)
| Also, oxidation
48
How is ATP produced in the Kreb's cycle?
Substrate level phosphorylation
| Phosphate comes from substrate
49
What does Acetyl CoA + oxaloacetate form in the Kreb's cycle?
Citrate (before first carboxylation)
50
What is Decarboxylation?
Removal of carbon dioxide
51
Where does the Kreb's cycle happen?
Matrix of mitochondria
52
What is the main purpose of the Kreb's cycle?
Reduce coenzymes
53
How many times does the Kreb's cycle turn per glucose molecule?
2
54
Why is ATP counted as a coenzyme?
It is required for enzymes to work as it moves phosphate groups between reactions
55
Why is FAD used in one specific step of the Kreb's cycle rather than NAD?
It is a coenzyme for a different enzyme that is used in that one specific step
56
What occurs to the reduced FAD/NAD in oxidative phosphorylation?
They are oxidised
57
What happens to ADP in oxidative phosphorylation?
Phosphorylated by chemiosmosis to produce large quantities of ATP
58
Where does oxidative phosphorylation occur?
Membrane in cristae in mitochondria
59
What happens to the electrons that are released by oxidising NADH and FADH in oxidative phosphorylation?
They go through the ETC using mobile electron carriers.
| This releases energy to power proton pumps
60
What do the proton pumps do in oxidative phosphorylation?
Pump H+ ions from the mitochondrial matrix to the intermembrane space.
61
What does the pumping of protons produce in oxidative phosphorylation??
An electrochemical gradient
62
What is oxygen known as in oxidative phosphorylation?
The final electron acceptor
63
What happens to the electrons at the end of the ETC in oxidative phosphorylation?
They are accepted by oxygen. This also combines with H+ ions to form water
64
What happens due to the electrochemical gradient in oxidative phosphorylation?
H+ ions in the intermembrane space flow through ATP synthase into the mitochondrial matrix which joins ADP+Pi to form lots of ATP
65
How is anaerobic respiration different?
Doesn't use oxygen
Doesn't involve Link reaction, Kreb's cycle or oxidative phosphorylation
Doesn't involve mitochondria (in cytoplasm)
Final electron acceptor is pyruvate
Lower ATP yield as only 1 stage - glycolysis
66
What are the 2 types of anaerobic respiration?
Alcoholic fermentation
| Lactate fermentation
67
What is produced it lactate fermentation?
Lactate and NAD
68
What happens in lactate fermentation?
Reduced NAD from glycolysis transfers hydrogen to pyruvate to form lactate and NAD
NAD is then reused in glycolysis
69
What are the positives of lactate fermentation?
Glycolysis can continue when oxygen is low so small amounts of ATP can be made to keep some biological processes going.
Cells can tolerate high levels of lactate
Lactate converted back to glucose by gluconeogenesis
70
What are the negatives of lactate fermentation?
Only small amounts of ATP are produced.
| Lactate is toxic.
71
Where does alcoholic fermentation occur?
In yeast
72
What does alcoholic fermentation produce?
Carbon dioxide, ethanol and NAD
73
What happens in alcoholic fermentation?
CO2 is removed from pyruvate to form ethanal.
Reduced NAD from glycolysis transfers hydrogen to ethanal to form ethanol and NAD
NAD is then reused in glycolysis
74
What are the positives of alcoholic fermentation?
Produces some ATP by glycolysis when Oxygen is low
75
What are the similarities between lactate fermentation and alcoholic fermentation?
Takes place in cytoplasm
Starts with glycolysis (produces pyruvate)
Regenerates NAD
Releases less energy than aerobic respiration
No oxygen
76
What are the differences between lactate fermentation and alcoholic fermentation?
LF - Mammals (some bacteria), produces lactate, 1 step, No other products
AF - Yeast cells (some plants), produces ethanol, 2 steps, also produces CO2
77
What is the definition of respiratory substrate?
An organic molecule that can be broken down in respiration to release energy
78
What is the primary respiratory substrate?
Glucose
79
What respiratory substrate releases the most energy?>
Lipids
80
Why do lipids release the most energy?
They have the most hydrogen atoms per unit mass, so they produce more reduced coenzymes in respiration so more ATP is produced.
81
Why do organisms not respire lipids or proteins first?
They have other functions. Fats - insulation, Protein in muscles so respire glucose then fats then protein
82
What does the RQ value show?
What respiratory substrate is being respired and therefore what type of metabolism the organism has
83
How do you work out the RQ value?
Volume or moles of CO2 produced / Volume or moles of oxygen produced
84
What are the units for RQ?
No units
85
What is the RQ for carbohydrates?
1.0
86
What is the RQ for proteins?
0.9
87
What is the RQ for fats?
0.7
88
When can the RQ be more than 1.0?
When using carbohydrates and anaerobic respiration
89
With respirometers, what is used as a control test?
Glass beads with the same mass as the thing you are measuring. Makes sure any changes are due to the respiration of the thing you're testing
90
With respirometers, what causes the fluid to move?
The uptake of oxygen as the CO2 is removed by the soda lime
91
How do you calculate the volume of oxygen used?
Measure how far the fluid moved
| Pi X r squared X h
92
How would you calculate the rate of oxygen consumption?
Volume used / time
