Chapter 9: Cellular Respiration and Fermentation Flashcards
(104 cards)
1
Q
what do catabolic pathways do?
A
release stored energy by breaking down complex molecules
2
Q
The breakdown of organic molecules are ________
A
exergonic
3
Q
What does aerobic respiration consume and yield?
A
consumes: organic molecule + O2
yields: ATP
4
Q
What is fermentation?
A
a partial degradation of sugars that occurs without O2
5
Q
What is anaerobic respiration?
A
similar to aerobic respiration but consumes compounds other than O2 (inorganic molecule, nitrate, sulfate, ferric ions)
6
Q
What is used to trace cellular respiration
A
glucose
7
Q
What catabolic pathways are used in cellular respiration?
A
aerobic and anaerobic
but typically referred to as a aerobic process
8
Q
What are the 3 different types of catabolic pathways
A
- aerobic respiration
- fermentation
- anaerobic respiration
9
Q
How does transferring electrons during chemical reactions effect energy stored in organic molecules?
A
The transfer of electrons RELEASES stored energy
10
Q
What is a redox reaction?
A
chemical reactions that transfer electrons between reactants
11
Q
what is oxidation?
A
when a substance loses electrons
12
Q
what is reduction?
A
when a substance gains electrons
13
Q
What is a reducing agent?
A
an electron donor
14
Q
what is an oxidizing agent?
A
an electron receptor
15
Q
During cellular respiration glucose is (oxidized/reduced)?
A
oxidized
16
Q
During cellular respiration O2 is (oxidized/reduced)?
A
reduced
17
Q
The oxidation of C6H12O6 produces _______
A
6 CO2
18
Q
The reduction of 6 O2 produces __________
A
6 H2O
19
Q
Electrons from organic compounds are usually first transferred to _____
A
NAD+
20
Q
NAD+ is a _________
A
coenzyme
21
Q
NAD+ _______ electrons
A
accepts
22
Q
NAD+ is a __________ agent
A
oxidizing
23
Q
What is the reduced form of NAD+?
A
NADH
24
Q
NAD+ plus an electron is ________
A
NADH
25
What is the structural difference between NAD+ and NADH?
NADH has two hydrogens in its hexagonal structure vs. NAD+ which has 1
26
NADH passes the electrons to the _________
electron transport chain
27
What are the 3 stages of harvesting energy from glucose?
1. Glycolysis
2. Citric Acid
3. Oxidative Phosphorylation
28
Which stage of cellular respiration accounts for the most ATP production?
oxidative phosphorylation
29
What is oxidative phosphorylation powered by?
redox reactions
30
In glycolysis and the citric acid cycle, what process produces ATP?
substrate level phosphorylation
31
What transfers a phosphate group from an organic substance to ADP?
Enzymes
32
What is glycolysis?
The stage of cellular respiration that breaks down glucose into two pyruvate
33
What are the two major phases of glycolysis?
1. Energy Investment
| 2. Energy Payoff
34
How many ATP are used in the Energy Investment phase of Glycolysis?
2 are used
35
What is produced in the Energy Payoff Phase of glycolysis?
4 ATP
2 NADH
2 H+
36
What is the net production of ATP?
2 ATP
37
What are the molecular stages of glycolysis investment phase?
1. Glucose
2. Glucose 6-Phoshate
3. Fructose 6- Phosphate
4. Fructose 1, 6-phosphate
5. G3P (Glyceraldehyde 3- Phosphate)
DHAP (Dihydroxyacetone Phosphate)
38
What are the molecular stages of glycolysis payoff phase?
1. 1, 3-Biphospho-glycerate
2. 3-Phospho-Glycerate
3. 2-Phospho-Glycaerate
4. Phosphoenol-Pyruvate (PEP)
5. Pyruvate
39
What are the enzymatic stages of the glycolysis investment phase?
1. Hexokinase
2. Phosphoglyco-isomerase
3. Phospho-fructokinase
4. Aldolase
5. Isomerase
40
What are the enzymatic stages of the glycolysis payoff phase?
1. Tri-phosphate dehydronase
2. Phospho-glycerokinase
2. Phospho- glyceromutase
3. Enolase
4. Pyruvate kinase
41
What is step 1 of glycolysis?
Hexokinase changes Glucose into Glucose 6-Phosphate
42
How does Hexokinase change glucose into glucose 6-phosphate?
transfers a phosphate group from ATP to glucose
43
How does the charge on the transferred phosphate effect the Glucose molecule?
makes it more chemically reactive and traps the sugar in the cell
44
What is step 2 of the glycolysis?
Phosphoglyco-isomerase changes Glucose 6-Phosphate to Fructose 6-Phosphate
45
What is step 3 of the glycolysis?
Phospho-fructokinase changes Fructose 6-Phosphate into Fructose 1, 6-Phosphate
46
In step 3 of glycolysis, where is the phosphate group transferred?
The opposite end of the fructose molecule
47
What step in glycolysis is key for regulation?
Step 3
48
What is step 4 of glycolysis?
Aldolase splits Fructose 1, 6-Biphosphate into G3P and DHAP
49
G3P and DHAP are both _______ sugars
3 carbon
50
Of the two products produced in step 4 of glycolysis, which one continues on to the next step?
G3P
51
What is step 5 of glycolysis?
Conversion between G3P and DHAP
52
Will the reaction between G3P and DHAP ever reach equilibrium?
no
53
What is step 6 of glycolysis?
Triose Phosphate Dehydrogenase is used to transform G3P into 1, 3-Biphospho-glycerate
54
NAD+ acts as a ______ agent in step 6
oxidizing
55
G3P is (oxidized/reduced) by the transfer of electrons to NAD+
oxidized
56
What is the G3P oxidation energy used to do in step 6?
attach a phosphate group to the oxidized substrate
57
What is step 7 of glycolysis?
Phosphoglycerokinase transforms 1, 3-Biphospho-Glycerate into 3-Phosphoglycerate
58
What provides the energy for step 7 of glycolysis?
2 ATP
59
What happens to the carbonyl group of G3P is step 7 of glycolysis?
It is oxidized into a carboxyl group (COO-) of an organic acid
60
In step 7 of glycolysis, what happens to one of the phosphate groups in 1,3-Biphospho-glycerate?
It undergoes substrate level phosphorylation which means that the phosphate group is transferred to ADP producing 1 ATP
61
What is step 8 of glycolysis?
Phosphoglycomutase transforms 3-phospho-glucerate into 2-phospho-gluterate
62
What is the critical change in step 8 of glycolysis?
The phosphate is relocated from the end of the 3 carbon chain to the middle
63
What is step 9 of glycolysis?
Enolase converts 2-phospho-glycerate into phosphoenol-pyruvate (PEP)
64
What is produced in step 9?
water molecules
65
What happens to the structure of the molecule during step 9?
Enolase causes a double bond to form in the substrate by extracting a water molecule
66
What is the final step of glycolysis? (step 10)
Pyruvate kinase tranforms phosphoenol-pyruvate (PEP) into pyruvate
67
What happens to the final phosphate group in step 10 of glycolysis?
The final phosphate group is transferred from PEP to ADP producing one ATP
68
What is required for the pyruvate to enter the mitochandrion in eukaryotic cells
the presence of O2
69
Before the citric acid cycle can begin what must happen to the pyruvate?
pyruvate must transform into Acetyl CoA
70
What are the steps required for pyruvate to turn into acetyl CoA?
1. loss of CO2
2. oxidation of NAD+
3. Addition of Coenzyme A
71
What is the main difference between the structure of pyruvate and acetyl coA?
pyruvate has a 3 carbon backbone and Acetyl CoA has 2
72
What is the first step of the citric acid cycle?
Acetyl-CoA adds it two carbons acetyl group to oxaloacetate (3 carbons) to produce citrate
73
What is step 2 of the citric acid cycle?
Citrate is converted to its isomer, isocitrate, by loosing and gaining a water molecule
74
What is step 3 of the citric acid cycle?
Isocitrate is oxidized, reducing NAD+ to NADH and losing a CO2 molecule to form alpha-ketoglytarate
75
What is step 4 of the citric acid cycle?
Alpha-ketoglytarate loses CO2, a NAD+ is reduced into NADH, and the remaining molecule is attached to coenzyme A by an unstable bond which then forms Succinyl CoA
76
What is step 5 of the citric acid cycle?
The Co-enzyme is displaced by a phosphate group
77
What is step 6 of the citric acid cycle?
Succinate is oxidized by FADH2
78
What are the inputs/outputs of step 6 of the citric acid cycle?
input: FAD
output: FADH2
79
What is step 7 of the citric acid cycle?
Fumarate is converted to malate
80
What are the inputs and outputs of step 7 of the citric acid cycle?
input: H2O
81
What is step 8 of the Citric acid cycle?
Malate is transformed into oxaloacetate
82
How is malate is (oxidized/reduced)?
Oxidized
83
What are the inputs and outputs of step 8 of the citric acid cycle?
input- NAD
| output- NADH
84
Where is the phosphate group in step 5 of the citric acid cycle placed after its displacement?
A GDP molecule forming GTP
85
If ATP is generated in step 5 of the citric acid cycle why is it produced?
GTP transfers its phosphate group to ADP and then produces ATP and GDP
86
What is step 6 of the citric acid cycle?
Succinate looses two hydrogens and turns into Fumarate
87
Where does Succinate deposit its hydrogens?
The hydrogens are transferred from FAD which turns into FADH2
88
In step 6 of the citric acid cycle succinate is (oxidized/reduced)?
oxidized
89
What is step 7 of the citric acid cycle?
Fumarate uses H2O to rearrange its structure into Malate
90
What is step 8 of the citric acid cycle?
Malate turns into Oxaloacetate
91
Is malate (oxidized/reduced)?
oxidized
92
Where are the hydrogen ions transferred in step 8 of the citric acid cycle?
To an NAD+ ion
93
How many CO2 molecules are produced in one citric acid cycle?
2
94
How many NADH molecules are produced in one citric acid cycle?
3
95
How many H2O molecules are used in the citric acid cycle?
2
96
How many H2O molecules are produced in the citric acid cycle?
1
97
How many FADH2 molecules are produced in one citric acid cycle?
1
98
What are the products of the citric acid cycle?
```
2 coenzyme A
3 NADH
1 FADH2
2 CO2
1 ATP
```
99
How many ATP molecules per glucose molecule are produced in the citric acid cycle and glycolysis?
4 ATP
100
Where is the electron transport chain located?
the inner membrane
101
Electrons move from a (less/more) electronegative electron carrier to a (less/more) electronegative electron carrier
less
| more
102
What happens as electrons move from a less to more electronegative electron carrier? What is released?
Free energy
103
The proteins in the electron transport chain are grouped together in ________________
multiprotein complexes
104
What are prothetic groups?
nonprotein components such as cofactors and coenzymes
