All of the following are true about Henderson-Hasselbalch equation except
If pKa < pH then A- > HA i.e. dissociated
if pKa > pH, then HA > A- i.e. not dissociated
When Concentration of A- and HA are equal then pH=pKa
None of the above
All of the following are sequence of events in the transport of bicarbonate
Tissues like liver generate CO2 by cellular respiration
CO2 + H2O in the presence of carbonic anhydrase in RBC results in H2CO3
H2CO3 dissociates into H+ and HCO3-
H+ is taken up by the Hemoglobin and HCO3- is exchanged for PO4-
All of the following regarding Oxy-Hb dissociation curve are true except?
Shift to the right means more O2 is released to the tissues
Low pH, high PCO2, increased H+ concentration and increased 2,3DPG all cause a shift to the right
Hemoglobin and Myoglobin both have the same type of curve
Proton binding by Hb reduces oxygen affinity is called the Bohr effect
Oxygen has >200 times greater affinity for Hb than CO
all of the following regarding enzymes are true except?
The velocity of all enzyme reactions is dependent on the concentration of the Substrate
The initial velocity of product formation (vi) proportional to Concentration of ES
Velocity continues to increase with increasing substrate concentration
In competitive inhibition Vmax is decreased and Km is unchanged, in noncompetitive inhibition Vmax remains unchanged and Km is changed
All of the following regarding allosteric enzyme are correct except
Regulation via allosterism can be more powerful since activators don't use catalytic site
Inhibitors have stronger effect than at active site
changes can be rapid
Allosteric enzyme has a sigmoid curve
all of the above
All of the following are irreversible steps in Glycolysis except
Glucose to Glucose 6 phosphate
Fructose 6 phosphate to Fructose 1,6 bisphosphate
PEP to Pyruvate
Glyceraldehyde 3 phosphate to 1,3 Bisphosphoglycerate
All of the following regarding Glucokinase are true except?
low Km for glucose
High Vmax for glucose
indirectly inhibited by fructose 6 phosphate and stimulated by glucose
Not inhibited by Glucose 6 phosphate
Mutation of this enzyme cause MODY 2 and also play a role in gestational diabetes
All of the following about PFK1 are true except
PFK 1 irreversibly commits G6P to glycolysis
PFK1 is allosterically inhibited by ATP
PFK1 is allosterically activated by AMP and fructose 2,6 bisphosphate
none of the above
Pyruvate Kinase deficiency causes hemolytic anemia
All of the following are true about Warburg effect except?
Proliferating cells get ATP from glycolysis not Oxidative Phosphorylation
Glycolysis is up regulated by oncogenes
Damaged mitochondria so no TCA cycle only glycolysis
Works for all body cancers including brain
All of the following about PDC (pyruvate dehydrogenase complex) are true except
Co factor for E1 is B1, Cofactor for E2 is lipoic acid and cofactor for E3 is FAD/NAD
E1 is X linked
PDH deficiency causes lactic acidosis and a type of subacute necrotizing encephalomyelopathy (Leigh disease)
Following all are the fates of pyruvate except
Transmination becomes Alanine
Dehydrogenation becomes acetyl CoA (by PDH in the presence of Oxygen)
In the absence of oxygen becomes lactate
Carboxylation to Oxaloacetate
PDH kinase inactivates PDC
The only substrate level ATP production in TCA cycle is from succinyl CoA to succinate
TCA cycle produces NADH for OxPhos, OxPhos produces ATP
All of the following about ETC is correct except?
Complex I cofactor is NADH
Complex II - Cofactor FADH2
CoQ only component of ETC not protein bound
Complex III - cytochrome b-c1
ETC reduces NADH and FADH2
All of the following statements are true except
Rotenone is inhibitor of complex 1 in ETC
Inhibition of Complex 1 causes a decrease in proton gradient
Oligomycin is an ATP synthase inhibitor - which increases the proton gradient
2,4 Dinitrophenol is an uncoupling agent - which increases proton gradient
The primary carbon-containing molecules that are substrates for gluconeogenesis are alanine from protein degradation, lactate from anaerobic glycolysis and glycerol from fat
All of the following are gluconeogenic enzymes except
Pyruvate carboxylase
PEP carboxykinase
Fructose 1,6 bisphosphatase
Glucose 6 phosphatase
All of the following are true about HMP shunt
Provides a source of NADPH and ribose
Oxidative (irreversible) reaction generates NADPH
Non oxidative (reversible) reaction generated Ribose 5 phosphate
1 and 2 only
All of the following are true about Reactive Oxygen Species
SOD, Catalase and Glutathione are all the enzymes that are used as a defense against oxygen toxicity
OH radicle attacks the C=C polyunsaturated lipid in membrane which yields malondialdehyde
Free radical production is part of host defense, intended to destroy microorganism and tumor cells
All of the above
Acetaminphen
Normal amounts of which are sulphated or glucuronated for excretion
Excess is oxidized by Cyp 2E1 to toxic NAPQI
NAPQI cannot be metabolized
N acetyl cysteine is the treatment for acetaminophen toxicity
Ethanol
Dehydrogenated to Acetaldehyde by ADH which is then dehydrogenated by ALDH to acetyl CoA
Pyruvate is converted to lactate to generate NAD+ which can be used in the above dehydrogenase reactions as Hydrogen acceptor
Lactic acidosis, gout, hypoglycemia and hyperlipidemia are all acute effects of ethanol metabolism
all of the above are correct
