Respiration Flashcards
1
Q
Metabolism
A
chemical reactions that occur in a cell
(Enzymes work together in metabolic pathways)
2
Q
Metabolic pathway:
A
– A series of reactions
– Each catalyzed by a different enzyme
– To build biological molecules
3
Q
Cellular respiration is:
A
– a set of reactions that produces ATP using an electron
transport chain
* Aerobic respiration
* Anaerobic respiration
4
Q
Aerobic respiration
A
electron acceptor is oxygen, very common,
the most efficient way to produce ATP
5
Q
Anaerobic respiration
A
electron acceptor is not oxygen, occurs
only in selected prokaryotes
6
Q
Metabolic pathways that produce ATP are:
A
cellular respiration
fermentation
7
Q
Fermentation is:
A
a set of reactions that produces ATP without oxygen
and an electron transport chain (ETC)
(very common as cells often limited by oxygen availability, inefficient way to produce ATP)
8
Q
ATP
A
adenosine triphosphate
9
Q
The electrons in ATP have high potential energy because
A
4 negative charges in its 3 phosphate groups repel each other
10
Q
Hydrolysis of ATP results in:
A
the transfer of the released phosphate group to a
different molecule and formation of high potential
energy bond
11
Q
Which cells in a human body perform cellular
respiration?
A
all
12
Q
What happens during cellular respiration?
A
- through a long series of carefully controlled redox
reactions - Carbon atoms of glucose are oxidized to form carbon
dioxide - Oxygen is reduced and forms water.
- The resulting change in Gibbs free energy is used to
synthesize ATP from ADP and Pi
13
Q
Redox reaction
A
an electron is transferred
from one molecule to another
– Reduced molecule gains electrons
– Oxidized molecule losses electrons
electrons can
– Be transferred completely from one atom to another
– Or simply shift their position in covalent bonds
14
Q
4 steps of cellular respiration
A
- glycolysis
- pyruvate processing
- citric acid cycle (krebs cycle)
- electron transport and chemiosmosis
15
Q
Is fermentation effective?
A
no
16
Q
How much ATP does each glucose molecule produce?
A
29
17
Q
How much ATP does fermentation produce?
A
2
18
Q
Byproducts of ethanol fermentation
A
CO2, ethanol, and NAD+
19
Q
What utilizes ethanol fermentation?
A
yeast
20
Q
Ethanol fermentation location
A
cytosol
21
Q
Byproduct of lactic acid fermentation
A
2 lactate
22
Q
Location of lactic acid fermentation
A
cytosol
23
Q
Lactic acid fermentation
A
Pyruvate accepts electrons from NADH
24
Q
What is used to regenerate NAD+?
A
- Lactic fermentation
- Ethanol fermentation
25
Why is NAD+ the limiting factor for glycolysis in the absence of oxygen?
NADH cannot be oxidized without oxygen
26
What is the limiting factor for glycolysis in the absence of oxygen?
NAD+
27
What can Glycolysis produce in the absence of oxygen?
ATP
28
What are the steps of fermentation?
1. Glycolysis
2. Fermentation
29
What is fermentation?
The production of ATP with the Electron Transport Chain
30
Why do cells that use anaerobic respiration make less ATP?
They cannot generate a large potential energy difference because they lack oxygen as an electron acceptor
31
Why is oxygen the most effective electron acceptor?
It is highly electronegative
32
What is the most effective electron acceptor?
Oxygen
33
Where did mitochondria originate from?
Bacteria
34
Can fats and proteins be used for cellular respiration?
yes
35
What produces glucose?
hydrolysis of sugars
36
What is the primary substrate for cellular respiration?
glucose
37
How much ATP is created through the Electron Transport Chain and Chemiosmosis?
25
38
How much ATP is created through glycolysis and the Citric Acid Cycle?
2 ATP and 2 GTP
39
What processes utilize oxidative phosphorylation?
The Electron Transport Chain and Chemiosmosis
40
What processes utilize substrate-level phosphorylation?
Glycolysis and the Citric Acid Cycle
41
What are the 2 methods of producing ATP?
1. Substrate-level phosphorylation
2. Oxidative phosphorylation
42
What is the purpose of ATP synthase?
Catalyze the phosphorylation of ADP and ATP
43
What spins ATP synthase?
The flow of protons
44
What is ATP synthase?
A large membrane-bound protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
45
What step used the proton gradient from the Electron Transport Chain to synthesize ATP?
CHEMIOSMOSIS
46
The proton gradient from the Electron Transport Chain is used to synthesize
ATP
47
What is created by the Electron Transport Chain?
Proton gradient
48
Gradients of ions are
form of potential energy
49
Where is the intermembrane space in the Electron Transport Chain?
Inside the cristae of the mitochondria
50
What is formed when protons are pumped into the intermembrane space?
A strong electrochemical gradient
51
What pumps the protons into the intermembrane space?
The energy released as electrons move through the Electron Transport Chain
52
Byproduct of the Electron Transport Chain
Water
53
Electron acceptor of the Electron Transport Chain
Oxygen
54
What is the function of protein complex IV?
Transfer electrons to oxygen and pump H+ from the matrix to the intermembrane space
55
What type of molecule is Cytochrome C?
Protein that contains a heme group
56
What molecule transfers electrons between protein complex III and protein complex IV?
Cytochrome C
57
Where does Ubiquinone transfer electrons to?
Protein complex III
58
How does Ubiquinone move?
Easily through the membrane to transfer electons
59
Where does Ubiquinone transfer H+ to?
The intermembrane space
60
What type of molecule in Ubiquinone?
lipid
61
Where do protein complexes I and II transfer electrons?
Ubiquinone
62
What byproduct is created when FADH2 donates electrons to the protein complex II?
FAD
63
What type of reaction occurs when FADH2 donates electrons to the protein complex II?
Redox reaction
64
Protein complex II
Not a proton pump
65
Where does FADH2 donate electrons to in electron transport?
Protein complex II
66
What byproduct is created when NADH donates electrons to the protein complex I?
NAD+
67
What type of reaction occurs when NADH donates electrons to the protein complex I?
Redox reaction
68
Protein Complex I
A proton pump that moves protons into intermembrane space against the gradient
69
Where does NADH donate electrons to in electron transport?
Protein complex I
70
All but one protein in the Electron Transport Chain are embedded where?
Inner mitochondrial membrane
71
Most Electron Transport Chain molecules are
Proteins containing chemical groups that facilitate redox reactions
72
How many high-energy molecules are used in the Electron Transport Chain?
10 NADH and 2 FADH2
73
What is the Electron Transport Chain?
The extraction of energy from high energy molecules formed during glycolysis, pyruvate processing, and the Citric Acid Cycle
74
How are ATP and GTP formed?
Substrate level phosphorylation
75
What is gradually converted into energy of NADH, FADH2, and ATP in the Citric Acid Cycle?
Potential energy of C-H bonds
76
Steps 1-3 of the Citric Acid Cycle
Oxidation of carbon atoms
77
What regulates the steps of the Citric Acid Cycle?
NADH and ATP via feedback inhibition
78
What regulates the creation of citrate?
ATP
79
What happens to the Citric Acid Cycle when energy supplies are high?
The cycle slows down
80
4 products of the Citric Acid Cycle
1. 2CO2
2. 3NADH
3. FADH
4. GTP
81
Substrate in the Citric Acid Cycle
Acetyl CoA
82
How many reactions occur in the Citric Acid Cycle?
8
83
What happens during the Citric Acid Cycle?
Oxidation and recycling of carboxylic acids
84
What is citrate formed from?
Acetyl CoA and oxaloacetate
85
Substrate in pyruvate processing
Coenzyme A
86
What happens during pyruvate processing?
Another molecule of NADH is synthesized and one of the carbon atoms is oxidized to CO2
87
What enzyme catalyzes pyruvate?
Pyruvate dehydrogenase
88
Where is pyruvate that is produced during glycolysis transported to?
Into the mitochondria
89
Location of the Electron Transport Chain in prokaryotes
Plasma membrane
90
Location of the Citric Acid Cycle in prokaryotes
Cytoplasm
91
Location of pyruvate processing in prokaryotes
Cytoplasm
92
Location of glycolysis in prokaryotes
Cytoplasm
93
Location of the Electron Transport Chain in eukaryotes
Inner mitocondrial membrane
94
Location of the Citric Acid Cycle in eukaryotes
Mitocondrial matrix
95
Location of pyruvate processing in eukaryotes
Mitocondrial matriX
96
Location of glycolysis in eukaryotes
Cytoplasm
97
What is the only step in cellular respiration that uses O2?
The Electron Transport Chain
98
What does the H+ gradient produce?
Lots of ATP
99
Electron Transport Chain
NADH and FADH2 are oxidized to build the H+ gradient
100
What is created during the Citric Acid Cycle?
A lot of NADH and FADH2, and some ATP
101
Another name for the Citric Acid Cycle
Krebs Cycle
102
Citric Acid Cycle
Acetyl CoA is oxidized to CO2
103
What is created in pyruvate processing?
NADH
104
Pyruvate processing
Pyruvate is oxidized to form acetyl CoA and CO2
105
Most potential energy contained in glucose is retained in
The 2 pyruvate molecules
106
ATP in phosphofructokinase
Acts as an allosteric regulator
107
High ATP concentrations cause
1. ATP to bind to the regulatory site
2. Change in the enzyme shape
3. Decrease in reaction rate at the active site
108
Phosphofructokinase binding sites for ATP
1. Active site (high affinity)
2. Regulatory site (low affinity)
109
High levels of ATP during glycolysis inhibit
The enzyme phosphofructokinase
110
When do cells stop glycolysis?
When ATP is abundant
111
Feedback inhibition
An enzyme in the pathway is inhibited by the product of that pathway
112
Glycolysis is regulated by
feedback inhibition
113
The speed of glycolysis depends on
the need for ATP
114
Glycolysis occurs when
A cell needs ATP
115
When does substrate-level phosphorylation occur?
Glycolysis and the Citric Acid Cycle
116
Substrate-level phosphorylation
ATP is produced by the enzyme-catalyzed transfer of a phosphate group from an intermediate substrate to ADP
117
Energy payoff phase
Sugar splits into 2 pyruvate molecules, 2 molecules of NAD+ are reduced to NADH, and 4 molecules of ATP are formed by substrate-level phosphorylation
118
Energy investment phase
2 molecules of ATP are consumed and glucose is phosphorylated twice
(NOTHING IS OXIDIZED OR REDUCED IN THIS PHASE)
119
Glycolysis consists of
1. Energy investment phase (3 reactions)
2. Energy payoff phase (7 reactions)
120
Glucose is broken down into
2 molecules of pyruvate
121
Where are all of the enzymes needed for glycolysis found?
Cytoplasm
122
How many enzymes are required for glycolysis?
10
123
What is not created by glycolysis?
CO2
124
What is not used during glycolysis?
Oxygen
125
Molecules that readily donate electrons to other molecules in cellular respiration
NADH and FADH2
126
Energy flow during respiration
GLUCOSE to NADH/FADH2 to ATP
127
Potential energy of NADH and FADH2
High potential energy
128
Electron carriers in cellular respiration
NADH and FADH2
129
In cellular respiration what is oxidized and what is reduced?
Carbon is oxidized
Oxygen is reduced
130
Fuel for most cellular activities
ATP
131
Hydrolysis of ATP products
Formation of ADP, inorganic phosphate, and energy
132
What type of reaction is Hydrolysis?
Highly exergonic
133
Why do the electrons in ATP have high potential energy?
The 4 negative charges in the 3 phosphate groups repel each other
134
Aerobic respiration
Respiration that requires oxygen
135
Anaerobic respiration
Respiration the does not require oxygen
136
Aerobic respiration electron acceptor
Oxygen
137
Anaerobic respiration electron acceptor
A molecule that is not oxygen
138
Fermentation
Set of reactions that produce ATP without oxygen and the electron transport chain
