Exam 4 Flashcards
1
Q
photoautotrophs
A
use co2 and light
2
Q
photoheterotrophs
A
use organics and light
3
Q
chemoautotrophs
A
use co2 and redox
4
Q
chemoheterotrophs
A
use organics and redox
5
Q
catabolism
A
degradative pathways, energy yielding
6
Q
anabolism
A
biosynthetic, energy requiring
7
Q
amphibolic
A
pathways with catabolism and anabolism
8
Q
common energetic product of protein, polysaccharide, and lipid breakdown
A
acetyl groups of acetyl coa
9
Q
common end products of protein, polysaccharide, and lipid breakdown
A
water, co2, ammonia
10
Q
collects electrons as hydride ions released during catabolism
A
NAD+ and turns into NADH
11
Q
provides reducing power for anabolic processes
A
NADPH
12
Q
fractionation of a cell extract
A
low speed, nuclei and unbroken cells. medium speed, mito, lysosomes. high speed, ribosomes.
13
Q
metabolome
A
set of low-molecular weight molecules present in an organism and excreted under a set of circumstances
14
Q
metabolomics
A
systematic identification of all these metabolites
15
Q
fluxomics
A
quantitative study of metabolite flow
16
Q
commits glucose to metabolism within cell
A
phosphorylation to G6P. cannot be transferred across plasma membrane
17
Q
function of adipose tissue and liver in glycolysis
A
source of glycerol 3 phosphate for TG synthesis. provides acetyl coa for FA synth
18
Q
where does glycolysis occur
A
all cell types in cytoplasm
19
Q
first committed step in glycolysis
A
2nd phosphorylation by PfK1
20
Q
insulin and glucagon mediated by this enzyme
A
PFK-1
21
Q
generates 1st mol of ATP in glycolysis. substrate level phosphorylation!
A
phosphoglycerate kinase
22
Q
glycolytic bypass used by RBCs
A
formation of 2,3 BPG from 1,3 BPG. lowers affinity of hemoglobin for o2
23
Q
forms 2nd mol of ATP in glycolysis
A
pyruvate kinase
24
Q
under aerobic conditions, NAD+ for glycolysis in regenerated from ?
A
ETC
25
regeneration of NAD+ under anaerobic conditions
lactate dehydrogenase reduces pyruvate to lactate
26
lactic acidemia
inadequate oxidation, overactive lactate production
27
glucose yield under anaerobic conditions
2 atp, 2 lactate
28
glucose yield under aerobic conditions
2 atp, 2 nadh, 2 pyruvate (total 30-32 atp)
29
major glycolytic enzymes regulated
hk, pfk1, and pk
30
hexokinase regulation (found in brain and muscle)
reversibly inhibited by its product G6P
31
glucokinase (replaces hexokinase in liver)
higher Km than hk. inhibited by F6P. always active
32
PK regulation
no regulation in brain and muscle. in liver, inhibited by ATP, alanine, and phosphorylation. activated by F6P (feed forward)
33
PFK1 activated by ?
amp, adp, F26BP
34
PFK1 inhibited by ?
ATP and citrate
35
unphosphorylated PFK2 effect
active kinase phosphorylates to increase F26BP. F26BP activates PFK1. increased glycolysis.
36
effect of starvation of PFK2
high glucagon > high cAMP > activation of protein kinase A > phosphorylates PFK2 > decreased F26BP > inhibits PFK1 > inhibits glycolysis
37
feeding effect on PFK2
high insulin > stimulates phosphatase > dephosphorylation of PFK2 > stimulates kinase > high F26BP > PFK1 activation > enhanced glycolysis
38
warburg effect
cancer cells divert glucose to pentose phosphate to produce NADPH for biosynthesis
39
tumor diagnosis using PET
radioactive glucose > positron emission > collision with electrons produce detectable gamma rays
40
generates acetyl coa from pyruvate
pyruvate dehydrogenase
41
acetyl coa contains a high energy ? linkage
thioester
42
conversion of 1 mol pyruvate to acetyl coa produces ? atp
2.5
43
pyruvate dehydrogenase is turned off when ?
energy level is high or oxygen is lacking
44
key regulatory enzymes of PDC
pdc kinase and phosphatase
45
location of TCA cycle
mitochondrion
46
? and ? initiate TCA cycle
acetyl coa and oxaloacetate
47
common limiting component of TCA cycle
oxaloacetate
48
oxidation of 1 mol of acetyl coa produces ? ATP
10
49
anaplerotic
replenish intermediates
50
pyruvate carboxylase
pyruvate to OAA
51
coenzyme of pyruvate carboxylase
biotin. activates and transfers CO2
52
PEP carboxylase
converts PEP to OAA
53
converts pyruvate to malate
malic enzyme
54
rate of TCA cycle is principally regulated by activity of ?
ETC. inhibition by high ATP and NADH
55
3 regulated steps of TCA cycle
citrate synthase, isocitrate dehydrogenase, and a-ketoglutarate
56
chemiosmotic hypthesis
coupling oxidation of NADH and FADH2 to synthesis of ATP
57
oxidative phosphorylation occurs where?
mitochondria
58
malate aspartate shuttle
cytoplasmic NADH > NAD+ > ETC
59
G3P shuttle
cytoplasmic NADH > FADH2 > ETC
60
ETC complexes that are proton pumps
1, 3 and 4. pump into intermembrane space
61
atp sythase structure
F0 in membrane is proton channel. F1 is the ATP sythesizing protein
62
binding change mechanism for ATP synthase
aenergy is required to bind ADP and phosphate and also to release ATP
63
MPTP
synthetic herion, inhibits complex 1
64
oligomycin
inhibits atp synthase
65
DNP
chemical uncoupler of ETC. destroys ph gradient, energy released as heat
66
thermogenesis
heat production by increasing metabolic rate. non shivering (uncoupling proteins), or shivering
67
synthesis of new glucose from noncarbohydrate precursors
gluconeogenesis
68
why does gluconeogenesis occur
some tissues can only run on glucose
69
where does gluconeogenesis primarily occur
liver
70
these tissues lack glucose 6 phosphatase which is required for release of glucose from cells
muscle and brain
71
precursors of glucose synthesis
lactate (from RBCs), glycerol (from adipose), amino acids (from muscle, especially alanine), propionate
72
catalyzes G6P to glucose
glucose 6 phosphatase
73
catalyzes fructose 1,6 phosphate to F6P
fructose bisphosphatase
74
catalyzes pyruvate to OAA
pyruvate carboxylase
75
catalyzes OAA to phosphoenolpyruvate
PEPCK (phosphoenolpyruvate carboxykinase)
76
what coenzyme does pyruvate carboxylase require
Biotin
77
conversion that contains a malate or aspartate intermediate. why?
OAA to phosphoenolpyruvate. necessary for transport out of mitochondrion. uses malate dehydrogenase or aspartate aminotransferase
78
where do galactose and glycogen enter gluconeogensis pathway
G6P
79
where dose fructose enter gluconeogensis pathway
DHAP
80
how does fat enter gluconeogenesis
fat > glycerol > G3P > DHAP
81
where do AA and lactate enter gluconeogenesis
as pyruvate
82
catalyzes lactate to pyruvate
lactate dehydrogenase
83
catalyzes alanine to pyruvate
alanine aminotransferase
84
catalyzes glycerol to G3P to DHAP
glycerol kinase and G3P dehydrogenase
85
additonal investment for entry into favorable gluconeogenesis over unfavorable reversal of glycolysis
4 high energy phosphate bonds
86
cori cycle
gluconeogenesis in liver produces glucose which is transported to RBCs. RBCs convert to lactate which is transferred to liver
87
alanine cycle
liver converts alanine to glucose. muscle converts glucose to alanine
88
Physiological conditions favoring gluconeogenesis
fasting, stress, exercise, low carb
89
stimulation of insulin
released by beta cells at high blood glucose
90
insulin functions
promotes fuel storage after food intake. promotes growth. binds receptors that: reverses glucagon stimulate phosphorylation, stimulates protein synth, and AA and glucose uptake into cells
91
stimulation of glucagon
released by alpha cells, repressed by glucose and insulin presence
92
glucagon functions
mobilizes stored food. maintains blood glucose. binds receptors that cause: glycogen degradation and inhibits synth, activates gluconeogenesis,
93
epinephrine function
mobilizes fuels during stress
94
cortisol function
increases blood glucose,
95
insulin synthesis
subunit peptides stored in pancreatic beta cells. initially pre-proinsulin. "pre" n term sequence is cleaved as enters RER. proinsulin transported to golgi. leaves golgi in vesicle and protease cleaves c-peptide to activate. glut2 mediated transport of glucose into beta cells stimulates exocytosis of insulin from vesicles
96
activates adenylate cyclase
glucagon (liver) and epinephrine (muscle)
97
adenylate cyclase function
converts atp to cyclic amp
98
cyclic amp function
activates protein kinase a
99
breaks down cAMP
phosphodiesterase
100
allosteric regulator of PFK1 and fructose bisphosphatase
fructose 2,6 bisphosphate
101
effect of phosphorylation on PFK2 in liver
inhibits kinase domain which converts F6P to F26BP. activates phosphatase domain which performs reverse
102
effect of F26BP on glycolysis
enhances
103
reverses PKA mediated phosphorylation
insulin
104
effect of phosphorylation on PFK2 in muscle
opposite the effect in liver
105
fructose derived from ?
sucrose
106
galactose derived from ?
lactose
107
mannose derived from ?
ingested polysaccharides
108
fructose entry into glycolysis and gluconeogenesis
fructose to F1P by fructokinase. to glyceraldehyde and DHAP by aldolase
109
mannose entry into glycolysis and gluconeogenesis
mannose to M6P by hexokinase. to F6P by isomerase
110
fructosuria
deficiency of fructokinase. relatively benign
111
fructose intolerance
deficiency of aldolase B. BAD!
112
galactose metabolism
to Galactose 1P by galactokinase. to glucose 1P by uridylyltransferase. to G6P by phosphoglucomutase
113
classical galactosemia
deficiency in uridylyltransferase
114
non classical galactosemia
deficiency in galactokinase
