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biochem test 2-3
lectures 20-22
86
Biochemistry
Graduate
02/24/2011

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Term
what does negative delta G mean
Definition
reaction is spontaneous; releases heat (exergonic)
Term
what does positive delta G mean
Definition
reaction isn't spontaneous; absorbs heat (endergonic)
Term
what does it mean when delta G equals 0
Definition
reaction is at equilibrium and no energy change occurs
Term
what is maximum work equal to?
Definition
Delta G
Term
what is standard T
Definition
25C
Term
what is delta G for hydrolysis of ATP forming ADP
Definition
-32 kJ/mol 1 mol of ATP has 32 more kJ of stored energy than ADP
Term
what is delta G for hydrolysis of ATP forming AMP
Definition
-45 kJ/mol
Term
Why is detla G of ATP>AMP more exergonic?
Definition
PPi is rapidly degraded by pyrophosphatase, so the conc of PPi is very low, so that drives the reaction
Term
energy released by catalysis is stored in the chemical form of
Definition
NADH, NADPH, ATP
Term
how is anabolism characterized
Definition
reduction and hydration
Term
where are reducing equivalents from nutrients stored in oxidation reactions of catabolism?
Definition
NADPH, NADH, FADH2
Term
what is the source of reducing equivalents for the reduction reactions of anabolism?
Definition
NADPH
Term
What is the maintained NAD+/NADH ratio
Definition
100/1
Term
What is the maintained NADP+/NADPH ratio?
Definition
1/100
Term
What is the maintained ATP/(ADP+AMP) ratio
Definition
4/1
Term
Describe Delta G and Delta Go in and out of equilibrium
Definition
They will be equal in equilibrium and not out of equilibrium
Term
describe phosphate transfer potential
Definition
A com[pound with a more negative Delta Go can transfera phosphate to a compound with a more positive Delta Go
Term
in catabolism, what are nutrients oxidized with?
Definition
NAD+ and FAD

CAT = NAD and FAD
Term
the energy released in catabolism of stored nutrients is stored in:
Definition
reducing cofactors: NADH and FADH2
Term
2 examples of oxidized form?
Definition
NAD+
NADP+
Term
2 examples of reduced form?
Definition
NADH
NADPH
Term
why do you want a lot of NAD+ comopared to NADH?
Definition
so you have enough NAD+ for catabolism of nutrients
Term
why do u want a lot of NADPH compared to NADP+
Definition
so you have enough for anabolism
Term
reducing equivalents have:
Definition
The H attached
Term
reducing equivalents are for:
Definition
anabolism
Term
what is the overall glycolysis reaction
Definition
glucose+2 ADP + 2 Pi + 2 NAD+ >>> 2 pyruvate + 2 ATP + 2 NADH
Term
under what conditions is glycolysis the main energy provider
Definition
anaerobic
Term
what is required to get energy from pyruvate?
Definition
oxygen
Term
why do R BCs use only glucose for energy
Definition
they have no mitochondria
Term
what is the first reaction in glycolysis and why does it happen
Definition
glucose>>>glucose-6-phosphate
to prevent diffusion of glucose out of GLUT
Term
what are the first 3 reactions of glycolysis called
Definition
"energy-input stage"
Term
what happens in the first 3 reactions of glycolysis?
Definition
2 ATP are used to form fructose-1,6 biphosphate (a more reactive molecule)
Term
what are the last 7 reactions called (of glycolysis)
Definition
"energy output stage"
Term
what is the first step of the energy output stage of glyc?
Definition
cleave hexose to 2 triose
Term
what happens to the 2 phosphate groups on 1,3-BPG
Definition
transferred to ADP to make ATP
Term
what happens to pyruvate?
Definition
oxidation (catabolism) to CO2 in TCA cycle
Term
what is the major energy producing pathwya in anaerobic cells?
Definition
oxidation of pyruvate to CO2 in TCA cycle
Term
what happens to pyruvate in anaerobic conditions/cells without a mitochondria?
Definition
pyruvate is reduced to lactate
Term
what is the reducing agent when pyruvate is reduced to lactate?
Definition
NADH
Term
What must be regenerated under anaerobic conditions?
Definition
NAD+
Term
in yeast and some bacteria, what happens to pyruvate?
Definition
pyruvate is reduced to ethanol to regenerate NAD+
Term
ATP using reactions use what as substrates
Definition
hexose
Term
ATP producing reactions use what as substrates
Definition
triose
Term
Total number of ATP produced in glycolysis? Net?
Definition
4; 2
Term
Delta G for glycolysis in cells?
Definition
-72
Term
which reactions are exergonic in glycolysis?
Definition
1,3,10
Term
All reactions (other than 1,3,10) have what delta G?
Definition
0
Term
what glycolysis steps are regulated
Definition
1,3,10 (they are ireversible)
Term
how are the 3 regulated steps kinases? names?
Definition
allosterically regulated by kinases
hexokinase
PFK-1
pyruvatekinase
Term
Significance of PFK-1?
Definition
catalyzes committed step of glycolysis and is the regulated step
Term
3rd step of glycoslys:
Definition
fructose-6-phosphate to fructose-1,6-biphosphate (useing PFK-1)
Term
write out steps of glycolysis
Definition
Term
what does pyruvate recycle?
Definition
NAD+
Term
under aerobic conditions, how is NAD+ regnerated
Definition
oxidative phosphorylation in the mitochondria
Term
which 2 steps produce ATP in stage 1?
Definition
glucose>glucose-6-P
fructose-6-P>fructose-1,6-bisP
Term
which enzymes catalyze reactions that use ATP as a substrate?
Definition
hexokinase, glucose-6 phosphate isomerase , PFK-1
Term
which enzyme catalyzes the reaction that produces NADH
Definition
G3P (glyceraldehyde3-phosphate)
Term
what does pyruvate dehydrogenase do?
Definition
converts pyruvate into acetyl CoA and CO2
Term
What does Thrymine Pyrophosphate do? TPP
Definition
attacks pyruvate and causes CO2 to leave
and carries hydroxyethyl to lipoamide
Term
what does lipoamide do?
Definition
oxidyzes hydroethyl to acetyl and carries to to CoA
Term
what does CoA do?
Definition
carries aceetyl to TCA cycle
Term
describe structure and placement of UQ
Definition
hydrophobic: membrane
Term
where is pyruvate produced
Definition
cytosol
Term
what are the substrates for the electron transport chain?
Definition
NADH and UQH2
Term
what is the first reaction of the TCA cycle?
Definition
combines acetyl CoA and oxaloacetate to form citrate
Term
what does the second part of the TCA cycle do?
Definition
converts citrate back to oxaloacetate and CO2
Term
Delta G for TCA cycle?
Definition
-54.8
Term
citrate can be converted to:
Definition
fatty acids
Term
alpha-ketoglutarate can be converted to:
Definition
amino acids
Term
succinyl Co-A can be converted to:
Definition
heme
Term
oxaloacetate can be converted to:
Definition
sugars
Term
total oxidation of glucose to CO2 yields how much ATP
Definition
32
Term
what produces most of the energy for aerobic cells?
Definition
oxidation of acetyl coA
Term
5 required cofactors for PDH
Definition
Thiamine Pyrophosphate
Lipamide
FAD/FADH2
CoA
NAD+/NADH
Term
describe NAD+/NADH
Definition
polar and cytosolic
Term
what is the primary use of NADH and CoEnzA in TCA
Definition
energy production of ATP
Term
draw out citric acid cycle
Definition
Term
what 3 reactions of the citric acid cycle are irreversible/regulated?
Definition
Acetyl CoA>citrate
isocitrate>alpha-ketoglutarate
slpha-ketoglutarate>succinyl CoA
Term
what bond provides the energy for substrate level phosphorylation
Definition
thioester bond of succinyl CoA
Term
what is succinatedehydrogenase
Definition
complex 2 of the electron transport chain
Term
which reaction of the citric acid cycle has a postive delta G
Definition
maleatedehydrogenase
Term
what does pyruvate carboxylate do?
Definition
pyruvate+bicarbonate=oxaloacetate
Term
what is the overall reaction catalyzed by PDH:
Definition
pyruvate + NAD+ + CoA >>> Acetyl CoA + Co2 + NADH
Term
which reaction of TCA cycle is used for substrate level phosphorylation
Definition
succinyl CoA >>> Succinate
Term
wha tkey metabolite ratio is responsible for moving maleate in forward direction?
Definition
NADH/NAD+<<<<0
Term
important anaplerotic reactoin?
Definition
using pyruvate carboxylase to change pyrufate and bicarbonate into acetyl CoA
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