Lecture 3 Flashcards
(115 cards)
1
Q
process of glycolysis
A
glucose is converted to pyruvate
2
Q
process of respiration
A
- pyruvate converted to 3 molecules of CO2
3
Q
3 pathways involved in cellular respiration
A
- pyruvate oxidation, CAC, and ETC
4
Q
process of fermentation
A
-converts pyruvate into lactic acid or ethyl alcohol
5
Q
is fermentation aerobic or anaerobic
A
anaerobic
6
Q
is cellular respirarion aerobic or anaerobic
A
aerobic
7
Q
Waste products in cellular respiration
A
H20 and CO2
8
Q
Waste products in fermentation
A
lactic acid or ethanol and CO2
9
Q
net energy trapped/glucose in cellular respiration
A
32 ATP
10
Q
net energy trapped/glucose in fermentation
A
2 ATP
11
Q
Where does glycolysis occur
A
in the cytosol
12
Q
what does glycolysis
A
converts glucose into 2 molecules of pyruvate
13
Q
end product of glycolysis
A
2 ATP and 2 NADH
14
Q
what do steps 1-5 of glycolysis require
A
ATP; energy investing reactions
15
Q
what do steps 1-6 of glycolysis yield
A
NADH and ATP (energy- harvesting rxns)
16
Q
preparation phase of glycolysis
A
conversion of glucose to G3P
17
Q
what is the second phase of glycolysis
A
G3P converted to pyruvate
18
Q
When are 2 ATP used in glycolysis
A
steps 1 and 3
19
Q
A
step 6
20
Q
A
steps
21
Q
each glucose molecule yields…
A
2 pyruvate, 2 NADH, 2H+ and 2 ATP
22
Q
Where does pyruvate oxidation occur
A
in the mitochondrial matrix
23
Q
what are products from pyruvate oxidation
A
acetate and CO2
24
Q
how is acetyl coA produced and during which process
A
when acetate binds to coenzyme A; pyruvate oxidation
25
pruvate oxidatio is a multistep rxn catalyzed by..
pyruvate dehydrogenase complex
26
what is glycogen
storage form of glucose, mainly in liver and muscle
27
when does glycogen release glucose
when energy demands are high
28
when is glucose polymerized to form glycogen
when the organism has no immediate need for energy from glucose breakdown
29
release of insulin is anabolic or catabolic
anabolic
30
release of glucagon is anabolic or catabolic
catabolic
31
what does glycogen synthase do
control enzyme for synthesis of glucose
32
what does glycogen phosphorylase do
control enzyme for breakdown of glucose
33
what is gluconeogenesis
conversion of glucose from pyruvate
34
what are the 3 irreversibel steps in glycolysis
- phosphoenolpyruvate --> pyruvate + ATP
- fructose-6 phosphae --> fructose- 1,6-bisphosphate
- glucose --> glucose - 6-phosphate
35
T or F: gluconeogenesis is NOT the exact reversal of glycolysis
true
36
what is the Cori Cycle
metabolic process and chemical pathway during which lactic acid produced in the muscles is converted to glucose by the liver and moved back to the muscles to be metabolized again.
37
pentose phosphate pathway is also known as...
hexose monophosphate shunt
38
PPP is an alternative to what
glycolysis BUT different in several ways
39
how is PPP different than glycolysis
- five-carbon sugars including ribose are produced from glucose
- oxidizing agent is NADP+ and reduced to NADPH
- begins with two oxidation steps to give ribulose-5-phosphate
40
what is starting point of CAC
acetyly coA
41
acetyl group is oxidized to what in CAC
2 molecules of CO2
42
what is released energy captured by in the CAC
ADP, NAD+, FAD, and GDP
43
pyruvate oxidation is endergonic or exergonic
exergonic
44
what happens in pyruvate oxidations
one NAD+ is reduced to NADH
45
pyruvate oxidation reaction
pyruvate + NAD+ + CoA --> NADH + H+ + CO2
46
for each molecule of glucose, how many times does CAC occur
2x
47
what are inputs of CAC
acetyl coA, water, oxidized electron carriers and GDP
48
what are oxidized electron carriers in CAC
3 NAD+ and FAD
49
what are outputs in CAC
2 CO2, reduced electron carriers and GTP
50
what are reduced electron carriers in CAC
3 NADH, 3 H+, and FADH2
51
What are important steps of CAC
- NAD+ is reduced to NADH + H+ ( steps 3,4,8)
- one GTP is produced (step 5)
- one FADH2 is produced (step 6)
- two CO2 produced (steps 3 and 4)
52
each acetyl coA yields...
3 NADH + 3H+ + FADH2 + 2 CO2 and ATP
53
pyruvate oxidation and CAC regulated by?
concentrations of starting molecules
54
what happens if O2 is present during pyruvate oxidation
oxygen accepts electrons and H2O it formed
55
what forms ATP in pyruvate oxidation
when energy is released by oxidation of electron carriers
56
What is ETC carried out by
four closely related multusubunit membrane bound complexes and two electron carriers: coenzyme Q and cytochrome c
57
what are the two electron carriers in the ETC
coenzyme Q and cytochrome C
58
what is oxygen reduced to in ETC
to water
59
what is result of protons in ETC
protons are pumped across the inner membrane to the intermembrane space which creates a pH gradient
60
where is ATP produced during oxidative phosphorylation
in the mitochondrion
61
what drives ATP production in chemiosmotic coupling
the flow of protons through the pore in the synthase drives ATP production
62
in conformational coupling, a change in the shape of the synthase causes what
releases bound ATP that has already been formed
63
P/O ratio
number of moles of Pi condumes in phosphorylation to the numebr of moles of oxygen atoms consumed in oxidation
64
when is P/O when NADH is oxidize
2.5
65
what is P/O when FADH2 is oxidized
1.5
66
phosphorylation process rxn
ADP + Pi --> ATP + H2O
67
oxidation process rxn
1/2O2 + 2H+ + 2e- --> H2O
68
what processes does corneal metabolism involve
aerobic oxidation, anaerobic glycolysis, and PPP
69
the lens mostly depends on what for ATP production
anaerobic metabolism
70
which processes are limited in the epithelium
aerobic glycolysis and Krebs cycle
71
under normal conditions, the retina will prefer which process
a high rate of anaerobic glycolysis
72
Where is PPP particularly active
in phosphoreceptors for rhodopsin regeneration and ribose prodution for nucleotide synthesis
73
how are lipids transported in the blood stream
through lipoproteins
74
which biomolecules are packaged into several classes of lipoproteins for transport
cholesterol and its fatty acid esters
75
how is each lipoprotein classified
by density; protein vs lipid content
76
function of chylomicrons
made in the intestine and transport dietary TGs from intestine to other tissues
77
VLDL
made in liver and transport lipids synthesized in the liver to other tissues
78
LDL
transport cholesterol to cells
79
when is LDL formed in the blood
when VLDLs lose TG and apoproteins
80
HDL
transports cholesterol from peripheral tissue to the liver for catabolism and excretion in bile
81
which cholesterol is considered good
HDL
82
HDL or LDL: high levels associated with INCREASED risk of heart disease
LDL
83
what are hormones
intracellular messenher produced in ductless gland of endocrine system
84
types of hormones
steroids, polypeptides, and amino acid derivativesster
85
examples of steroids
estrogen and androgen
86
examples of polypeptides
insulin and glucagon
87
examples of amino acid derivatives
epinephrine
88
roles of hormones
maintainance of homeostasis and regulation of growth and development
89
secondary messengers
hormone binds to receptor site on target cell to initiate series of rxns
90
binding of secondary messenger to receptor site causes what
triggers production of cAMP from ATP which is catalyzed by adenylate cyclase
91
ex of secondary messenger
cyclic AMP
92
what does cAMP do
causes actual changes
93
what are reactions of cyclic AMP mediated by
stimulatory G protein
94
G protein is bound to..
plasma membrane
95
G protein subunits
alpha, beta, and gamma
96
when is G protein inactive
when GDP is bound to alpha subunit
97
what activates G protein
binding of the hormone to its receptor which causes a GDP --> GTP exchange
98
active G protein stimulates ______ which catalyzes what
stimulates adenylate cyclase which catalyzes conversion of ATP to cAMP and pyrophosphate
99
Receptor tyrosine kinase
spans the membrane of the cell and has a hormone receptor on the outside and a tyrosine kinase portion on the inside
100
which hormones regulate carb metabolism
epinephrine and glucagon and insulin
101
epinephrine
- derived from tyrosine
- acts on muscle tissue to raise glucose levels
102
what is glucagon
polypeptide of 29 amino acid sequences
103
what allows the release of glucagon
alpha cells of the islets of langerhans
104
what does glucagon do
binds to specific receptor sites to set off chain of events to make glucose available to organism
105
hormone amplification
activation of G protein which stimulates adenylate cyclase several times and increases production of cAMP
106
what kind of hormone is insulin
peptide hormone released by liver
107
what does insulin do
stimulates anabolic pathway to store fuels
108
3 functions of glucose
- increase glucose uptake into cells via glucose transporter
- increase glycogen synthesis and decrease breakdown
- increase fatty acid synthesis
109
what are targets of insulin
muscle, liver, and adipose
110
diabetes mellitus
insulin either defective or insulin receptor is defective (or reduced in quantity)
111
transducin
g protein in the rod outer segment discs
112
what is transducin activated by
light activated rhodophsin (R*)
113
what does activated transducin do
activated transducin binds, and activates phosphodiesterase
114
what does phosphodiesterase do
an enzyme that lowers cGMP levels via the rxn cGMP --> GMP
115
what does cGMP do
controls ion channels of the cell involved in the visual signal
