87 - lactose build up in the muscle during vigorous activity causes muscle fatigue and soreness .
the above statement is false . it is glycolytically generated acid that causes muscle fatigue and soreness .
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88 - when NADPH is needed from the pentose phosphate pathway , excess ________ is converted to glycolytic intermediates by a sequence of reactions which can operate in reverse .
ribulose - 5 - phosphate .
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89 - which state of PFK , does AMP preferentially bind ?
a- to the R state
b- to the T state
c- to both states without any preference
d- to neither
answer is a . to the R state .
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90 - yeast alcohol dehydrogenase and mammalian liver alcohol dehydrogenase , both require ____
a- Mg + 2
b- Zn + 2
c- calcium
d- iron
answer is b . ZINC .
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91 - glyceraldehyde 3 phosphate is phosphorylated to produce 1 , 3 bisphosphoglycerate to produce one molecule of NADH in the presence of the enzyme GA3P dehydrogenase .
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92 - alcoholic fermentation results in the regenration of NAD + along with the conversion of pyruvate to _______ and CO2 .
answer is ethanol.
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93 - the deficiency of which vitamine results in a condition called beri beri ?
thiamine is the answer .
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94 - transketolase has a thiamine pyrophosphate cofactor and catalyses the transfer of a c2 unit from XU5P to R5P .
true .
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95 - the three products of glycolysis are ATP , NADH and pyruvate .
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96 - what does ATP do to PFK , at high concentrations?
- it acts as an allosteric inhibitor , by binding to the T state .
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97 - the level of available ______, regulates hemoglobin's oxygen affinity ?
answer is 2 ,3 BPG.
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
TO KNOW MORE ABOUT HMP SHUNT CLICK HERE
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Showing posts with label glycolysis. Show all posts
Showing posts with label glycolysis. Show all posts
Tuesday, January 8, 2008
11 - biochemistry mcqs - 76 to 86 - glycolysis
76 - an enzyme that transfers phosphoryl groups between ATP and a metabolite ?
a- kinase
b- aldolase
c- enolase
d- mutase
answer is a .
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77 - the ion essential for kinase activity ?
answer - magnesium .
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78 - the enzyme which catalyses the transfer of a functional group from one position to other ?
a- mutase
b- enolase
c- aldolase
d- kinase
answer is a . mutase . phosphoglycero mutase converts the 3 phosphoglycerate to 2 phosphoglycerate .
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79 - compounds with high phosphoryl group transfer potentials are formed during glycolysis .
the above statement is true .
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80 - when the need for ribose 5 phosphate exceeds that of NADPH , reversal of the transaldolase and transketolase reactions , diverts ribose 5 phosphate from the glycolytic pathway .
the above statement is true .
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81 - after phosphorylation , galactose reacts with the UDPG to form glucose 1 phosphate and ___________ before an epimerization reaction ?
answer is UDP - GALACTOSE
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82 - fructose metabolism in muscle requires only one step before it can enter into glycolysis ?
the above statement is true .
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83 - it has been demonstrated that triose phosphate isomerase has a reaction rate that is diffusion controlled and is therefore an example an enzyme that has reached catalytic perfection ?
the above statement is true .
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84 - enolase catalyses a reaction that results in the formation of a high energy intermediate .
the above statement is true . the enzyme enolase catalyses the conversion of the 2 - phosphoglycerate to phosphoenolpyruvate .
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85 - the statement which describes glycolysis stage II , the stage of energy recovery are ?
answer is --- two molecules of glyceraldehyde 3 phosphate are converted to pyruvate and four molecules of ATP are generated .
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86 - ribulose 5 phosphate is converted to xylulose 5 phosphate by the action of the enzyme ?
a- isomerase
b- epimerase
c- kinase
d- aldolase
answer is b .
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
TO KNOW MORE ABOUT HMP SHUNT CLICK HERE
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a- kinase
b- aldolase
c- enolase
d- mutase
answer is a .
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77 - the ion essential for kinase activity ?
answer - magnesium .
-----------------------------------------------------------------------------------
78 - the enzyme which catalyses the transfer of a functional group from one position to other ?
a- mutase
b- enolase
c- aldolase
d- kinase
answer is a . mutase . phosphoglycero mutase converts the 3 phosphoglycerate to 2 phosphoglycerate .
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79 - compounds with high phosphoryl group transfer potentials are formed during glycolysis .
the above statement is true .
----------------------------------------------------------------------------------
80 - when the need for ribose 5 phosphate exceeds that of NADPH , reversal of the transaldolase and transketolase reactions , diverts ribose 5 phosphate from the glycolytic pathway .
the above statement is true .
---------------------------------------------------------------------------------
81 - after phosphorylation , galactose reacts with the UDPG to form glucose 1 phosphate and ___________ before an epimerization reaction ?
answer is UDP - GALACTOSE
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82 - fructose metabolism in muscle requires only one step before it can enter into glycolysis ?
the above statement is true .
-----------------------------------------------------------------------------
83 - it has been demonstrated that triose phosphate isomerase has a reaction rate that is diffusion controlled and is therefore an example an enzyme that has reached catalytic perfection ?
the above statement is true .
------------------------------------------------------------------------------
84 - enolase catalyses a reaction that results in the formation of a high energy intermediate .
the above statement is true . the enzyme enolase catalyses the conversion of the 2 - phosphoglycerate to phosphoenolpyruvate .
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85 - the statement which describes glycolysis stage II , the stage of energy recovery are ?
answer is --- two molecules of glyceraldehyde 3 phosphate are converted to pyruvate and four molecules of ATP are generated .
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86 - ribulose 5 phosphate is converted to xylulose 5 phosphate by the action of the enzyme ?
a- isomerase
b- epimerase
c- kinase
d- aldolase
answer is b .
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
TO KNOW MORE ABOUT HMP SHUNT CLICK HERE
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9 - biochemistry mcqs - 65 to 75 - glycolysis
65 - which enzyme is the major control point for glycolysis in muscle under most conditions .
a- glucokinase
b- hexokinase
c- phosphofructokinase
d- pyruvate kinase
answer is c .
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66 - ATP in fast twitch muscle fibres is supplied predominantly by which type of glycolysis
a- aerobic
b- anaerobic
answer is b . anaerobic glycolysis .
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67 - the rate of ATP production by anaerobic glycolysis can be upto 100 times faster than that of oxidative phosphorylation .
the above statement is true .
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68 - under which conditions is the complete oxidation of pyruvate mediated by citric acid cycle ?
a- aerobic
b- anaerobic
answer is a .
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69 - impaired substrate cycling may lead to a lack of nonshivering thermogenesis and result in cold sensitivity in obese individuals .
the above statement is true .
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70 - which molecule acts as a signal amplifier when concentrations of ATP are low to increase the phosphofructokinase activity ?
a- ADP
b- ATP
c- AMP
d- NADH
answer is c . AMP .
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71 - Ribulose 5 phosphate ( RU5P ) is converted to ribose 5 phosphate ( R5P ) by the enzyme ?
a- ribulose 5 phosphate dehydrogenase
b- ribose 5 phosphate dehydrogenase
c- RU5P ISOMERASE
d- R5P ISOMERASE
the answer is C .
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72 - which aminoacid side chain forms the schiff base with the substrate in the aldolase reaction ?
a- arginine
b- serine
c- tyrosine
d- lysine
answer is d.
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73 - lactate formed in skeletal muscle cells during anaerobic glycolysis is carried back to the liver , where it is used to synthesize
a- glucose
b- fructose
c- fatty acids
d- amino acids
answer is a .
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74 - flouride ion inhibits glycolysis by inhibiting the action of which enzyme ?
answer - enolase
aldolase
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75 - what is the enzyme which catalyses the formation of glyceraldehyde 3 phosphate and dihydroxy acetone phosphate ?
a- aldolase
b- enolase
c- kinase
d- mutase
answer is a . aldolase .
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
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a- glucokinase
b- hexokinase
c- phosphofructokinase
d- pyruvate kinase
answer is c .
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66 - ATP in fast twitch muscle fibres is supplied predominantly by which type of glycolysis
a- aerobic
b- anaerobic
answer is b . anaerobic glycolysis .
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67 - the rate of ATP production by anaerobic glycolysis can be upto 100 times faster than that of oxidative phosphorylation .
the above statement is true .
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68 - under which conditions is the complete oxidation of pyruvate mediated by citric acid cycle ?
a- aerobic
b- anaerobic
answer is a .
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69 - impaired substrate cycling may lead to a lack of nonshivering thermogenesis and result in cold sensitivity in obese individuals .
the above statement is true .
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70 - which molecule acts as a signal amplifier when concentrations of ATP are low to increase the phosphofructokinase activity ?
a- ADP
b- ATP
c- AMP
d- NADH
answer is c . AMP .
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71 - Ribulose 5 phosphate ( RU5P ) is converted to ribose 5 phosphate ( R5P ) by the enzyme ?
a- ribulose 5 phosphate dehydrogenase
b- ribose 5 phosphate dehydrogenase
c- RU5P ISOMERASE
d- R5P ISOMERASE
the answer is C .
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72 - which aminoacid side chain forms the schiff base with the substrate in the aldolase reaction ?
a- arginine
b- serine
c- tyrosine
d- lysine
answer is d.
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73 - lactate formed in skeletal muscle cells during anaerobic glycolysis is carried back to the liver , where it is used to synthesize
a- glucose
b- fructose
c- fatty acids
d- amino acids
answer is a .
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74 - flouride ion inhibits glycolysis by inhibiting the action of which enzyme ?
answer - enolase
aldolase
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75 - what is the enzyme which catalyses the formation of glyceraldehyde 3 phosphate and dihydroxy acetone phosphate ?
a- aldolase
b- enolase
c- kinase
d- mutase
answer is a . aldolase .
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
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8 - biochemistry mcqs - 54 to 64 - glycolysis
54- in glycolysis ?
ans- glucose is converted inot 2 molecules of pyruvate by the synthesis of two NADH and 2 ATP molecules and utilisation of 2ATP molecules too .
- i dont wanna give u choices in this question because it confuses u a lot , so stick to the above statement .
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55 - the compound which reduces the affinity of pyruvate kinase for its substrate ?
a- phosphoenol pyruvate
b- pyruvate
c- NADH
d- ATP
answer is ATP .
The pyruvate kinase converts phosphoenol pyruvate to pyruvate and in this reaction ATP is synthesized .
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56 - in muscle , glycolytic flux is subject to regulation by substrate cycling .
the above statement is true .
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57 - a deficiency of type B aldolase , results in __________ intolerance , a self limiting genetic disease ?
a- fructose intolerance
b- glucose intolerance
c- galactose intolerance
d- ribose intolerance
the answer is a .
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58 - the isomerisation of glucose-6-phosphate to fructose-6-phosphate is catalysed by which enzyme ?
a- hexokinase
b- glucokinase
c- phosphoglucose isomerase
d- phosphofructo kinase
answer is c . phosphoglucose isomerase.
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59 - the glyceraldehyde 3 phosphate dehydrogenase reaction is exergonic and will therefore proceed in the forward direction ?
the above statement is false . the glyceraldehyde 3 phosphate dehydrogenase reaction is slightly endergonic , but is pulled forward by the subsequent reaction of phosphoglycerate kinase . phosphoglycerate kinase converts 1 , 3 bisphosphoglycerate to 3 phosphoglycerate .
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60 - the rate of NADPH production is controlled by the rate of glucose-6-phosphate dehydrogenase reaction .
the above statement is true .
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61 - the exclusion of water from the active site of hexokinase is responsible for preventing the hydrolysis of ATP from being the dominant reaction during catalysis .
the above statement is true .
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62 - phosphoglycerate kinase catalyses a step in glycolysis , which results in the formation of ATP .
the above statement is true . the enzyme phosphoglycerate kinase catalyses the conversion of 1 , 3 bisphosphoglycerate to 3 phosphoglycerate to produce one ATP .
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63 - The hexokinase has very low affinity for hexoses .
the statement is true .
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64 - in two steps mannose is converted to ______, to enter into the glycolytic pathway ?
a- fructose 6 phosphate
b- glucose 6 phosphate
c- fructose
d- glucose
answer is a .
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
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ans- glucose is converted inot 2 molecules of pyruvate by the synthesis of two NADH and 2 ATP molecules and utilisation of 2ATP molecules too .
- i dont wanna give u choices in this question because it confuses u a lot , so stick to the above statement .
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55 - the compound which reduces the affinity of pyruvate kinase for its substrate ?
a- phosphoenol pyruvate
b- pyruvate
c- NADH
d- ATP
answer is ATP .
The pyruvate kinase converts phosphoenol pyruvate to pyruvate and in this reaction ATP is synthesized .
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56 - in muscle , glycolytic flux is subject to regulation by substrate cycling .
the above statement is true .
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57 - a deficiency of type B aldolase , results in __________ intolerance , a self limiting genetic disease ?
a- fructose intolerance
b- glucose intolerance
c- galactose intolerance
d- ribose intolerance
the answer is a .
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58 - the isomerisation of glucose-6-phosphate to fructose-6-phosphate is catalysed by which enzyme ?
a- hexokinase
b- glucokinase
c- phosphoglucose isomerase
d- phosphofructo kinase
answer is c . phosphoglucose isomerase.
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59 - the glyceraldehyde 3 phosphate dehydrogenase reaction is exergonic and will therefore proceed in the forward direction ?
the above statement is false . the glyceraldehyde 3 phosphate dehydrogenase reaction is slightly endergonic , but is pulled forward by the subsequent reaction of phosphoglycerate kinase . phosphoglycerate kinase converts 1 , 3 bisphosphoglycerate to 3 phosphoglycerate .
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60 - the rate of NADPH production is controlled by the rate of glucose-6-phosphate dehydrogenase reaction .
the above statement is true .
------------------------------------------------------------------------------------------
61 - the exclusion of water from the active site of hexokinase is responsible for preventing the hydrolysis of ATP from being the dominant reaction during catalysis .
the above statement is true .
----------------------------------------------------------------------------------------------------------------
62 - phosphoglycerate kinase catalyses a step in glycolysis , which results in the formation of ATP .
the above statement is true . the enzyme phosphoglycerate kinase catalyses the conversion of 1 , 3 bisphosphoglycerate to 3 phosphoglycerate to produce one ATP .
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63 - The hexokinase has very low affinity for hexoses .
the statement is true .
---------------------------------------------------------
64 - in two steps mannose is converted to ______, to enter into the glycolytic pathway ?
a- fructose 6 phosphate
b- glucose 6 phosphate
c- fructose
d- glucose
answer is a .
TO READ COMPLETELY ABOUT GLYCOLYSIS CLICK HERE
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7 - glycolysis
Glycolysis is the sequence of reactions that converts glucose into pyruvate with the concomitant production of a relatively small amount of adenosine triphosphate (ATP). The word is derived from Greek γλυκύς (sweet) and λύσις (letting loose).
It is the initial process of most carbohydrate catabolism, and it serves three principal functions:
1. The generation of high-energy molecules (ATP and NADH) as cellular energy sources as part of aerobic respiration and anaerobic respiration; that is, in the former process, oxygen is present, and, in the latter, oxygen is not present
2. Production of pyruvate for the citric acid cycle as part of aerobic respiration
3. The production of a variety of six- and three-carbon intermediate compounds, which may be removed at various steps in the process for other cellular purposes.
As the foundation of both aerobic and anaerobic respiration, glycolysis is the archetype of universal metabolic processes known and occurring (with variations) in many types of cells in nearly all organisms. Glycolysis, through anaerobic respiration, is the main energy source in many prokaryotes, eukaryotic cells devoid of mitochondria (e.g., mature erythrocytes) and eukaryotic cells under low-oxygen conditions (e.g., heavily-exercising muscle or fermenting yeast).
In eukaryotes and prokaryotes, glycolysis takes place within the cytosol of the cell. In plant cells, some of the glycolytic reactions are also found in the Calvin-Benson cycle, which functions inside the chloroplasts. The wide conservation includes the most phylogenetically deep-rooted extant organisms, and thus it is considered to be one of the most ancient metabolic pathways.
The most common and well-known type of glycolysis is the Embden-Meyerhof pathway, initially explained by Gustav Embden and Otto Meyerhof. The term can be taken to include alternative pathways, such as the Entner-Doudoroff Pathway. However, glycolysis will be used here as a synonym for the Embden-Meyerhof pathway.
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