Cliff's - Chapter 3 - Cellular Respiration Flashcards
(94 cards)
1
Q
Cellular Respiration
(definition)
A
ATP-generating process
occurs within cells
2
Q
How is ATP formed? (simple)
A
energy extracted from glucose
forms ATP from ADP and Pi
3
Q
Chemical Equation
(energy production, cellular respiration)
A
C6H12O6 + 6 O2 –> 6 CO2 + 6 H2O + energy
4
Q
molecular formula glucose
A
C6H12O
5
Q
general molec formula glucose or carb
A
CH2O
(CH2O)n
6
Q
aerobic respiration
(definition)
A
cellular respiration in presence of O2
7
Q
Cellular respiration components
A
- Glycolysis
- Krebs cycle
- Oxidative phosphorylation
8
Q
Glycolysis
(definition)
A
glucose —> pyruvate
(decomposition)
9
Q
lysis (synonym)
A
decomposition
10
Q
intermediate products formed during glycolysis (how many?)
A
9
11
Q
each intermediate product of glycolysis is catalyzed by an
A
enzyme
12
Q
in 6 of the steps of glycosylation, magnesium ions are
A
cofactors that promote enzyme activity
13
Q
summary of glycoslyation
A
2 ATP added
2 NADH produced
4 ATP produced
2 Pyruvate formed
14
Q
why are 2 ATP added for glycosylation?
A
first several steps require input of energy
alters glucose in prep for subsequent steps
15
Q
how are NADH produced in glycosylation?
A
NAD+ + 2e- + H+ —> NADH
16
Q
NADH is a type of
A
coenzyme
17
Q
H+ to form NADH is obtained from
A
intermediate molecule during breakdown of glucose
18
Q
net ATP from glycolysis
A
2
(4 produced but 2 used)
19
Q
glycosylation occurs in the
A
cytosol
20
Q
Krebs Cycle
(definition)
A
details what occurs to pyruvate produced during glycosylation
(2 pyruvate produced during glycosylation)
multiply products of krebs cycle x2 to account for 2 pyruvate
21
Q
step leading to krebs cycle
A
pyruvate + CoA —> acetyl CoA
also produced: 1 NADH, 1 CO2
22
Q
CoA
A
coenzyme A
23
Q
initiating step of krebs cycle
A
acetyl CoA + oxaloacetate —> citrate
24
Q
7 intermediate products of krebs cycle
A
- citrate (3-carbon citrate)
- 3 NADH
- 1 FADH2
- CO2
- 1 ATP
25
FADH2
coenzyme, like NADH
accepts electrons during rxn
26
krebs cycle aka
citric acid cycle
or
tricarboxylic acid (TCA) cycle
27
TCA
tricarboxyclic acid
28
OAA
oxaloacetate
29
CO2 produced by krebs cycle is
CO2 animals exhale
30
memorize fig 4.1
cellular respiration
31
Oxidative Phosphorylation
extracting ATP form NADH + FADH2
32
electrons from NADH and FADH2 pass along the
(oxidative phosph)
electron transport chain (etc)
33
ETC consists of
proteins that pass electrons
carrier protein --\> carrier protein ---\> carrier protein
34
cytochromes
carrier proteins
include nonprotein parts containing iron
35
along each step of chain, electrons give up energy used to
phosphorylate ADP to ATP
36
NADH provides electrons --\> enough energy to generate
3 ATP
37
FADH2 ---\>
2 ATP
38
final electron acceptor of ETC
oxygen
39
1/2 O2 accepts two electrons and
forms H2O with 2 H+
40
cytochrome c
carrier proteins in ETC
so ubiquitous among living organisms that protein comapred among species to compare genetic relatedness
100-amino-acid sequence protein
41
glycolysis occurs in the
cytosol
42
1 glucose = how many ATP
(theoretically)
glycolysis
glycolysis (cytoplasm)
2 NADH
2 ATP
2 pyruvate
net: 2 ATP
43
1 glucose = how many ATP
(bw glycolysis and krebs)
2 pyruvate ---\> 2 acetyl CoA
2 NADH
44
1 glucose = how many ATP?
Krebs
2 acetyl CoA ---\>
6 NADH
2 FADH2
2 ATP
45
1 glucose = how many ATP
oxidative phosphorylation
1 NADH ---\> 3 ATP (x6)
1 FADH2 --\> 2 ATP (x2)
net: 38 ATP
butttttttttt
46
1 glucose = how many ATP
energy needed for ox. phosph.
2 NADH produced in cytoplasm during glycolysis transported to mitochondria for oxidative phosphorylation
thus
1 NADH ---\> 2 ATP (x6
47
Mitochondria is the site of
| (cellular respiration)
krebs cycle
oxidative phosphorylation
48
4 distinct areas of mitochondrion
1. outer membrane
2. intermembrane space
3. inner membrane
4. matrix
49
outer membrane
| (mitochondrion)
like plasma membrane
phosopholipid bilayer
50
intermembrane space
| (mitochondrion)
narrow area bw inner and outer membranes
H+ ions accumulate here
51
Inner membrane
form
(mitochondrion)
second membrane
phospholipid bilayer
convulations called cristae
52
inner membrane
fxn
(mitochondrion)
xite of oxidative phosophorylation
ETC removes electrons form NADH and FADH2
then transports H+ from matrix to intermembrane space
53
electron transport chain consists of
series of protein complexes
54
5 examples of protein complexes (ETC)
1. PC I
2. PC II
3. PC III
4. PC IV
5. ATP synthase
55
ATP synthase
protein complex in ETC
site of phosphorylation
ADP --\> ATP
56
Matrix
form
fxn (site of 2 processes of cellular respiration)
(mitochondrion)
fluid material
fills area inside inner membrane
site of:
1. Krebs cycle
2. pyruvate ---\> acetyl CoA
57
figure 4-2
chemiosmois in mitochondria
58
chemiosmosis is ATP generation when
energy stored in form of proton concentration gradient across membrane
59
chemiosmosis in mitochondria occurs during
oxidative phosphorylation
60
5 steps of chemiosmosis in mitochondria
1. krebs cycle ---\> NADH, FADH2 in matrix
2. electrons removed from NADH, FADH2
3. protons transported from matrix --\> intermembrane space
4. pH & electrical gradient across inner membrane created
5. ATP synthase generates ATP
61
1. Krebs cycle
| (chemiosmosis)
produces
NADH, FADH2 in matrix
CO2 generated
substrate-level phosphorylation produces ATP
62
2. oxidative phosphorylation
(chemiosmosis)
electrons removed from NADH, FADH2
by protein complexes in inner membrane
electrons move along ETC
63
3. protons transported from matrix to intermembrane compartment
(chemiosmosis)
transported via protein complexes
matrix --\> inner membrane ---\> intermebrane space
64
4. pH and electrical gradient across inner membrane created
(chemiosmosis)
conc. protons increases in intermembrane space --\> pH decreases
conc protons decreases in matrix ---\> pH increases
conc protons in matrix further decreases ---\>
electrons from ETC combine with H+ and O ---\> H2O
result:
proton gradient
electric charge gradient
65
proton and electric charge gradients in mitochondrion serve as
(chemiosmosis)
potential energy reserves
66
5. ATP synthase generates ATP
| (chemiosmosis)
ATP synthase allows protons in intermembrane compartment ---\> matrix
protons moving through channel generate energy --\>
ATP synthase --\> ATP
67
two types of phosphorylation
1. substrate-level phosphorylation
2. oxidative phosphorylation
68
ATP synthase
channel protein in inner membrane (part of ETC)
69
phosphorylation
metabolic process for generating ATP
70
substrate level phosphorylation
ADP + Pi ----\> ATP
substrate molecule donates high energy phosphate group
occurs durying glycolysis
71
substrate molecule
| (substrate level phosphorylation)
molecule with phosphate group
72
Oxidative phosphorylation
ADP + Pi ---\> ATP
Pi does not include energy for bond
electrons from ETC provide energy
energy electrons ---\> generate H+ gradient ---\> energy to ATP synthase ---\> energy to form ATP from ADP + Pi
73
Anaerobic Respiration
cellular respiration in the absence of oxygen
74
What is not going on in anaerobic respiration?
no electron acceptor to accept electrons at end of ETC
75
if no electrons at end of ETC
| (anaerobic respiration)
all NAD+ ---\> NADH
NADH accumulates
krebs cycle, glycolysis halt
no new ATP produced
cell dies
76
in order to proceed, krebs cycle and glycolysis both need
(anaerobic respiration)
NAD+ to accept electrons
77
anaerobic respiration prevents cell death due to lack of oxygen by
replenishing NAD+
so glycolysis can proceed
78
two common metabolic pathways
anaerobic respiration
alcohol
lactic fermentation
79
anaerobic respiration occurs in the
cytosol
| (alongside glycolysis)
80
Alcohol Fermentation
occurs in
plants
fungi (yeast)
bacteria
81
Steps of alcohol fermentation
1. Pyruvate --\> acetaldehyde
2. Acetaldehyde ---\> ethanol
82
pyruvate ---\> acetaldehyde
| (alcohol fermentation)
pyruvate ---\> CO2 + acetaldehyde
83
CO2 formed in first step of alcohol fermentation is source of
(pyruvate --\> acetaldehyde)
carbonation in fermented drinks (beer, champagne)
84
acetaldehyde ---\> ethanol
| (alcohol fermentation)
rxn driven by energy in NADH
releases NAD+
acetaldehyde ---\> ethanol + NAD+
85
ethanol produced in second step of alcohol fermentation is source of
acetaldehyde ---\> ethanol
alcohol in beer, wine
86
NAD+ is freed from NADH by this process
(alcohol fermentation)
energy from NADH drives rxn
acetaldehyde ---\> ethanol
NAD+ released
87
NAD+ released during alcohol fermentation allows
glycolysis to continue
88
in absence of O2, all NAD+ is bottled up in
NADH
89
without oxygen, oxidative phosphorylation cannot
accept electrons from NADH
90
ATP yield
alcohol fermentation
2 ATP
from glycolysis, for each 2 converted pyruvate
91
Lactic acid fermentation
pyruvate ---\> lactic acid (lactate)
in process
NADH ---\> NAD+
(NADH gives up electron)
92
NAD+ produced in lactic acid fermentation and alcohol fermentation used for
glycolysis
93
in humans + mammals
most lactate transported to...
liver
94
lactate that is transported to the liver of humans and other mammals is...
converted to glucose when surplus ATP available
