( CHO metabolism ( MCQ

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اشترك في: الخميس إبريل 04, 2013 10:28 pm

( CHO metabolism ( MCQ

مشاركةبواسطة دكتور كمال سيد » الاثنين مارس 07, 2016 4:58 pm

( CHO metabolism ( MCQ

Biochemistry MCQ

A substance that is not an intermediate in the formation of glucuronic acid from glucose is:-
UDP-galactose
UPD-glucose
Glucose-6-phosphate
UPD-glucuronic acid

Transport of glucose cross the cell membrance is stimulated by insulin in:-
Brain
RBCs
Liver
Skeletal muscles

The major process responsible for maintaining blood glucose 40hours after last meal:-
Glycolysis
Glycogenolysis
The pentose phosphate pathway
Gluconeogenesis

The major process responsible for maintaining blood glucose 4hours after last meal:-
Glycolysis
Glycogenolysis
The pentose phosphate pathway
Gluconeogenesis

Each of the following enzymes is required for the conversion of glycerol to glucose EXCEPT:-
Glucose-6-phosphatase
Glycerol-3-phosphate dehydrogenase
Phosphoenol pyruvate carboxykinase
Fructose 1.6 bisphosphtase

· in RBCs how many net molecues of ATP are generated when one molecule of glocuse is oxidized to lactate:-
0
1
2
12

· All the following about pentose phosphate path way are true EXCEPT:-
There is a net energy production of 8 ATP molecule.
NADPH+H is produced that is essential for lipids metabolism.
Deficiency of glucose -6- phosphate dehydrogenase leads to favism
Its intracellular location is cytosol

· Glucokinase:-
Is found in muscles
Has low affinity(high KM)to glucose
Allosterically inhibited by glucose -6- phosphate
Catalyzes a reversible reaction

· IN which compartment does pentose phosphate pathway occur?
The mitochondria
(The solube cytoplasm (cytosol
Both of them
Non of them

10)animal fed a high cholesterol diet shows decreased cholesterol synthesis by liver because of th inhibition of which one of the following enzyme:-
HMG CoA synthetase
HMGCoA reductase
Mevalonate kinase
HMG CoA lyase
صورة

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اشترك في: الخميس إبريل 04, 2013 10:28 pm

Re: ( CHO metabolism ( MCQ

مشاركةبواسطة دكتور كمال سيد » الاثنين مارس 07, 2016 5:00 pm

11)Succinyl CoA may undergoes one of the following fateEXCEPT:-
Heme synthesis
Activation of ketone bodies
Glycosaminoglycans synthesis
Gluconeogenesis

12)Pancreatic lipase:-
Is specific for the 1.3 ester linkage of triacylglycerols
Is specific for the 2 position of triacylglycerols
Specifically hydrolyzes 2 monoacylglycerols
Is specific for the phospholipids

13) which of the following changes would you expect in apatient with decreased activity of lipoprtien lipase?
Elevation of serum chylomicrons only
Elevation of both serum chylomicrons and VLDL
Elevation of HDL only
Elevation of both serum HDL and LDL

14)Cholesterol is the precursor of thefollowing compounds EXCEPT
Bile acids
Testosterone
B_Hydroxy butyrate
Progesterone

15) the catabolism of hemoglobin involve:
Oxidative cleavage of porphyrin ring
Formatin of urobilin
Liberation of CO
All of the above

16) δ-aminolevulonic acid synthetase activity:
Catalyzing rate limiting step in heme biosynthesis
Require co enzyme biotin
Occurs in cytosol
Stimulated by heavy metals as lead

17) a normal adult is placed on a diet deficient only in phynyalanine which of the following statement is correct:
Synthesis of proteins by the liver continues normally
Signs of myxedema will appear
Tyrosine is used to compensate missing phynylalanine
Tyrosine becomes an essential amino acid

18) which of the following statement is correct:
The end product of all amino acid catabolism is urea
All essential amino acids are glycogenic
Ornithine, citrulline and β-alanine are found in tissue proteins
In the presense of dietary source of tyrosine , phynyl alanine is not essential

19) amino transferases:
Catalyse reaction that result in production of ammonia
Catalyse irreversible reaction
Require pyridoxal phosphate as essential co-enzyme for the reaction
Are not able to catalyse transamination reaction s with essential amino acid

20) in the formation of urea from ammonia by urea cycle, all of the following are correct except:
The site of urea formatin is the kidney
Fumarate is produced
Aspartate supplys one of the nitrogen found in urea
Genetic deficiency of any one of enzymes can lead to hyper ammoemia
صورة

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اشترك في: الخميس إبريل 04, 2013 10:28 pm

Re: ( CHO metabolism ( MCQ

مشاركةبواسطة دكتور كمال سيد » الاثنين مارس 07, 2016 5:02 pm

21) removal of amino group from amino acids in man is performed mainly by:
Transaminatin only
Oxidative deamination only
Transamination followed by oxidative deamination
Non oxidative deamination

22) all of the following about serine is correct except:
it is essential for phosphoproteins synthesis
precursor of carnitine
reacts with palmityl Co-A to form sphingosine base
it gives choline by decarboxylation and transmethylation

23) which of the following amino acids can be metabolized to fatty acids in mammals:
histidine
methionine
arginine
leucine

24) which amino acid undergoes transamination to form glyoxlic acid:
alanine
aspartate
glycine
lysine

25) all of thefollowing are correct about ornithine except:
is a precursor about spermin and spermidine
it is non protein amino acid
is a source of N1 in purine bases
plays amajor role in urea cycle

26) all of the following about glutamate dehydrogenase are true except:
it catalses a reversible reaction
synthesis of non essential amino acxid
it is an enzyme that present in most tissues
its co-enzyme is FAD

27) alkptonuria is due to absence of :
homogintisic acid oxidase
phenyl alanine oxidase
tyrosine oxidase
dopa decarboxylase

28) the precursor of adrenaline is:
alanine
tryptophan
tyrosine
cysteine

29) phenylketonuria is:
associated with mental retardation
due to hereditary deficiency of phenylalanine hydroxylase
associated with excecretion of phenyl lactate and phenyl pyruvate
all of the above

· 30) the metabolism of tryptophan results in the production of a substance that:
forms heme
prevents albinism
causes vasoconstriction
causes phenylketonuria
صورة

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Re: ( CHO metabolism ( MCQ

مشاركةبواسطة دكتور كمال سيد » الاثنين مارس 07, 2016 5:04 pm

· 31) albinism is due to abscense of:
tyrosnase
Dopa oxidase
Tryptophan pyrrolase
homogintisic acid oxidase

· 32) in the gluconeogenesis each of the following is needed for the convertion of pyruvate to phosphoenolpyruvate except:
CO2
GTP
Pyruvate carboxylase
Pyruvate kinase

· 33) glycosuria may be caused by the following except:
Glycosuria in pregnancy
Diabetes mellitus
Diabetes insipidus
Low renal threshold for tubular reabsorption of glugose

· 34) all the following about glycogenolysis are true except:
It is the breakdown of glycogen to glucose
Glucose is the end product in liver and muscle
It is stimulated by adrenaline and nor adrenaline
Von-jierk's disease deficiency of glucose-6- phosphatase

· 35) diabetes mellitus is due to deficiency of the action of:
Glucagons
Insulin
Thyroxin
Adrenaline

· 36) fructose and galactose enter the liver and are phosphorylated at carbon :
1
3
6
5


37) oxidative decarboxylation of pyruvate requires :
biotin
cytochrome P 450
thiamin pyrophosphate
NADP+

38) the activity of phosphofructokinase-1 can be decreased by all the following except:
ATP
Citrate
Glucagon
AMP

39) pyruvate dehydrogenase is inhibited by the following except :
Acetyl Co-A
ATP
NADH+H
Insulin

40) all of the following are intermediates of tricarboxylic acid cycle except :
Citrate
Malate
Propionyl Co- A
Oxaloacetate
صورة

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اشترك في: الخميس إبريل 04, 2013 10:28 pm

Re: ( CHO metabolism ( MCQ

مشاركةبواسطة دكتور كمال سيد » الاثنين مارس 07, 2016 5:35 pm

41) cAMP directly activates:
Hexokinase
Glycogen synthase
Phosphofructokinase -1
Protein kinase

42) NADPH + H is produced by:
Pentose phosphate pathway
Glycolysis
Citric acid cycle
Uronic acid pathway

43) which of the following enzymes of glycolysis is utilized in gluconeogenesis:
Glukokinase
Aldolase
Phosphpfructokinase
Pyruvate kinase

44) gluconeogenesis occurs in
Mitochondria
Cytosol
Both of them
Non of them

45) apolipoproteinC-ΙΙ activates :
LCAT
ACAT
Lipoprotein lipase
HMG-CO Areductase
صورة


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