Biochem Practice Exam

Choose the best answer: 1. ____ Among the 1st tier of elements, this one predominates over all of them. A. hydrogen B. Carbon C. Nitrogen D. Oxygen 2. ____Which of the attributes of living things is the most impt. of all: A. capacity to extract energy from nutrients B. power to actively respond to changes in their environment. C. ability to differentiate D. ability to reproduce 3. ____The site of synthesis of ribosomal RNAs: A. nucleolus C. nucleus B. endoplasmic reticulum D. Peroxisomes 4.____Molecules that are able to cross the inner mitochondrial membrane. A. malate C. citrate B. pyruvate D. Ketone bodies 5. ____These molecules are found inside the mitochondrial matrix A. enzymes of glycogenolysis C. Enzymes of embden-Meyehoff pathway B. enzymes of Krebs cycle D. Most enzyme of gluconeogenesis 6.____A pathway found carried out inside the mitochondrial matrix by eukaryotes A. glycolysis C. Fatty acid synthesis B. hexose monophosphate pathway D. B-oxidation of fatty acids 7.____Oxidation of substrates in the mitochondrion involves A. Tranfer of electrons from NADH only to an atom of O 2 B. Oxidation of substrates to CO2 and H2O C. Coupled to oxidation of electrons carriers, NAD + and FAD D. acceptance of electrons from FAD to a molecule of O2 8.____The large subunit of prokaryotic ribosome is made up of these RNAs A. 28S, 5.8S RNAs C. 16S, 18S RNAs B. 23S, 5S RNAs D. 5.8 S, 28S RNAs 9.____The small subunit of eukaryotic ribosomes is made up of 30 proteins A. 28S RNA B. 16S RNA C. 5.8S RNA D. 18S RNA 10.___Important roles performed by smooth endoplasmic reticulum, except: A. synthesize polypeptides C. Detoxification of foreign drugs B. participate in glycogenolysis D. Release of CA++ ions for muscle contraction 11.____The face of Golgi stacks distended into the trans golgi network A. cis-face C. Entry face B. trans-face D. None of the above 12.____True of the Golgi complex: A. process N-linked low mannose oligosaccharides B. assemble O-linked high mannose oligosaccharides C. glycosyl kinases-enzymes catalyzing the process D. synthesize high mannose type of oligosaccharides 13.____The organelle that is the principal site of cholesterol assimilation from LDL A. mitochondrion C. Peroxisomes B. lysosomes D. Endoplasmic reticulum 14.____A process that the cells utilized to bring worn-out parts for digestion: A. endocytosis C. Phagocytosis B. exocytosis D. Autophagy 15.____A pump that mauintaind the relatively low pH inside the lysosomes: A. proton pump C. Na+/K+ ATPase pump + B. Na pump D. Ca+ ATPase pump 16.____an enzyme that is found in peroxisomes that degrades H 2O2:

A. urate oxidase B. D-amino acid oxidase

C. Catalase D. L-amino acid oxidase

17.____Factor/s that affect the transition of cell membranes from a gel-solid to a liquid crystalline form: A. composition of membrane proteins C. Amount of oligosaccharides attached B. concentration of type of fatty acids D. Thickness of the membrane 18.____Roles that specific membrane proteins (receptors) exerts: A. for cell movement C. As energy source of the cell B. functions of enzymes D. All of the choices 19.____The ff. Are important roles of cytoskeleton except: A. transport ions across membranes C. Maintain cell shape B. attachment of organelles D. Framework for moving organelles 20.____An enzymes that is used as a marker to denote the localization of the membrane matrix; A. Glucose 6 phosphatase C. Catalase B. Glutamate dehydrogenase D. Lactate dehydrogenase 21.____At what carbon are the functional groups of an aldotriose and a ketone A. Carbon 1; Carbon 2 C. Carbon 2; Carbon 4 B. Carbon 3; Carbon 5 D. Carbon 2; Carbon 1 22.____What sugar is pictured? How many isomers that it has?

A. D-fructose; 8 Galactose;16

B. D-Glucose;8

C. L-Glucose;16

D.

D-

23.____in the Fischer projection of L-ribolose, the –OH on the last chiral carbon is drawn: A. to the right B. above C. below D. To the left 24.____The disaccharide sucrose is composed of the monosaccharides: A. D-glucose + D-glucose C. D-glucose + D-fructose B. D-fructose + D-galactose D. D-glucose + D-galactose 25.____The structure (below) in the Haworth’s projection is:

A. α-D galactopyranose C. α-D glucopyranose B. β-D mannopyranose D. β-D glucopyranose 26.____The disaccharide composed of D-galactose and D-glucose is: A. maltose C. Sucrose B. Lactose D. Cellobiose 27.____The phenomenon of the reversible interconversion from the boat to the chair galactopyranose is termed as: A. Tautomerism C. Mutarotation B. E-Z isomerism D. Conformational isomerism

28.____The structure below is: A. Maltose B. Lactose

C. Cellulose D. Sucrose

29.____The polysaccharide that is the major structural material of wood and plants is: A. amylopectin C. Amylase B. glycogen D. Cellulose 30.____Name the polysaccharide made up of this piece of the chain; name the monosaccharide unit and the kind of acetal bond found:

A. glycogen; glucose; α 1-4 B. Cellulose; Cellubiose; β 1-4

C. Amylase; glucose; α 1-4 D. Chitin; cellubiose; α 1-6

31.____Name the glycosaminoglycan composed of the repeating disaccharide unit given; Name the bond within the repeating unit and the bond b/w 2 repeating units. A. B. C. D.

Dermatan sulfate; β 1-4; β 1-3 Heparan sulfate; α 1-4; β 1-4 Chondroitin sulfate; α 1-3; β 1-4 Hyaluronic acid; β 1-3; β 1-4

32.____Difference b/w the murein layer of gram positive and gram negative bacteria is that in the former: A. D- Ala of one chain and L-Lys of the other chain are connected by a pentaglycin cross-link B. lechoic acid protrudes out of murein layer C. the alternating amino acid residue chain is attached to the N-acetyl glucosamine backbone D.D- Ala of one chain and L-Lys of the other chain are connected by a direct amidelink 33.____The structure of penicillin responsible for inhibition of the transpeptidase enzyme that catalyzes the formation of the pentaglycin cross-link of the peptidoglycan layer: A.D- valine residue C. Acyl side Chain B. β- lactam ring D. L-cysteine residue 34._____Name the carbohydrates pictured below according to the functional group and number of carbon atoms; name the penultimate carbon:

A. Ketopentose; C2 B. Aldohexose; C3 C. Ketopentose; C4 D. Aldopentose; C4

35.____What sugar is pictured? How many isomers does it has?

A. D-fructose; 8 galactose; 16

B. D-glucose; 16

C. L-glucose; 8

D.

D-

36.____The structure in the Haworth’s projection is:

A. α-D galactopyranose B. β-D mannopyranose

C. α-D glucopyranose D. β-D glucopyranose

37.____The phenomenon of the reversible interconversion from the alpha to the beta and configuration of D-galactopyranose is termed as: A. tautomerism C. Mutarotation B. E-Z isomerism D. Stereoisomerism 38.____In amylopectin, the glucose molecules are connected by: A. alpha-1, 4-glycosidic bonds and alpha-1,6-glycosidic bonds C. alpha-1,4glycosidic bonds B. alpha-1, 6-glycosidic bonds D. Beta-1, 4- glycosidic bonds 39.____Name the polysaccharide made up of this piece of chain: name the repeating one of the molecule and the kind of acetal bond found: A. glycogen; glucose; α 1-4 B. cellulose; cellubiose; β 1-4 C. starch; galactose; α 1-6 D. chitin;cellubiose; α 1-6 40.___Name the glycosaminoglycan composed of the repeating disaccharide unit given; name the bond within the repeating unit and the bond b/w 2 repeating unit:

A. dermatan sulfate; β 1-4; β 1-3 1-4 B. heparin sulfate; α 1-4; β 1-4

C. Chondrotin sulfate; β 1-3; β D. Hyaluronic acid; α 1-2; β 1-4

41.____A type of glycolipid classed as a compound lipid; A. cephalin C. Sphingomyelin B. GM1 D. Beeswax 42.____An omega 6 fatty acid the serves as the immediate precursor in the synthesis of prostaglandins: A. linolenic acid C. Arachidonic acid B. docosahexanoic acid D. Linoleic acid 43.____The ff. PUFAs follows the non-conjugated system of double notation except: A. 16:ˆ 9 (palmitoleic acid) C. 18:3 ˆ6, 9, 12 (gamma-linoleic acid) B. 20:5 ˆ 5, 8, 11, 17 (EPA) D. 22:6 ˆ4, 7, 10,13,16,19 (DHA)

44.____This fatty acid, by the nature of its structure, has the highest melting point: A. CH2(CH2)7CH=CH-(CH2)7COOH C. CH3(CH2)5CH=CH-(CH2)7COOH B. CH2(CH2)4(CH=CHCH2)2(CH2)6COOH D. CH3CH2(CH=CHCH2)3(CH2)6COOH 45.____What reaction is involved in the process of attachment of fatty acid to a carbon of glycerol producing a monoacylglycerol moiety? A. neutralization C. Halogenation B. esterification D. Sponification 46.____The higher the iodine number of a fatty acid means. A. more carbon atoms are part of the structure B. less double bond are present in the structure C. less carbon atoms are found in the structure D. more double bond are present in the structure 47.____The fatty acids usually esterified at position 2 of the glycerol backbone of glycerophospholipids are: A. Palmitic or docosahexanoic acids C. Stearic or eicosapentaenoic acids B. linoleic or oleic acids D. Docosahexanoic acid or nenonic acids 48.____What are the lipid determine and whose relative concentrations are determine order to predict whether a premature infant would develop ARDS? A. phosphatidyl choline & sphingomyelin C. Phosphatidyl serine &cephalin B. Cephalin and sphingomyelin D. Lecithin & cephalin 49._____The glycerophospholipid that serves as an impt. Precursor in the synthesis of 2nd messengers known as phosphoinositides, like IP 3 and 1, 2 diacylglycerol: A. diphosphatidylglycerol C. Phosphatidylserine B. phosphatidylinositol D. Phosphatidyl choline 50.____This fatty acid is one of the 2 found usually N-acylated to carbon 2 of sphingosine forming the prerdominant type of sphingomyelins: A. stearic acid C. Oleic acid B. myristic acid D. Arachidic acid 51.____When a single glucose moeity is linked in a β-glycosidic bond at the carbon 1-hydro of sphingosine, the molecule is called: A. globoside C. Sulfatide B. cerebroside D. Ganglioside 52. This ganglioside serves as the receptor for cholera toxin in the gastro-intestinal lining theintestinal villi: A. GM1 B. GM2 C. GM3 D. GM4 53.____A primary bile acid: A. lithocholic acid B. Tauro cholic acid C. Cholic acid

D. Glycol cholic acid

54.____The enzyme deficient in Niemann-Pick disease: A. Beta glucosidase B. Beta galactosidase C. Hexoseaminidase A Sphingomyelinase

D.

55.____factors that determine the fluidity of biological membranes include: A. Chains of fatty acids, double bonds present in the fatty acids, concentration B. chains of fatty acids, double bonds present in the fatty acids only 56.____Structural characteristics of the lecithins include: A. inositol, phosphatidate, a net charge of -1 at pH 7.4 B. Choline, phosphatidate, a net charge of 0 at pH 7.4 C. ethanolamine, phosphatidate, a net charge of 0 at pH 7.4 D. choline, phosphatidate, a net charge of -1 at pH 7.4 57.____An omega 3 fatty acid: A. ϒ-linoleic acid B. Arachidonic acid C. Α-linoleic acid

D. Oleic acid

58.____What is the reaction wherein there is animal fat with a strong base? What is the reaction’s product? A.saponification, soaps C. Hydrogenation, ethers B. hydrolysis, esters D. Hydrogenations, soaps 59.____Structural characteristics of phosphatidylcholine of the lung surfactant: A. at sn-1of glycerol backbone is attached a palmic acid & sn-3 is attached a phosphorylcholine B. at sn-1 of glycerol backbone is attached a palmitic acid, at sn-2 is attached an arachidonic acid & at sn-3 is attached a phosphorylcholine C. at sv-1 of glycerol backbone is attached a palmic acid, at a sn-2 is attached a linolenic acid at sn-3 is attached a phosphorylcholine D. at sn-1 of glycerol backbone is attached a palmitic acid, at sn-2 is attached an oleic acid sn-3 is attached a phosphorylcholine 60.____Which part ofPAF makes it more soluble than the other lipids allowing PAF to as a soluble messenger in signal transduction? A. alkyl group at C-1 C. Nitrogenous base attached to the PO4 B. acetate group at C-2 D. Glycerol backbone 61.____An O-linked oligosaccharide is linked to the protein indirectly through this amino acid residue: A. serine B. Lysine C. Asparagines D. Aspartate 62.____The amino acid that does not possess any asymmetric carbon: A. lysine B. Glycine C. Leucine D. Tyrocine 63.____The parts of the structures of an amino acid that is used to refer to inorder to determined the configuration: A. alpha carbon and alpha amino group B. alpha carbon and alpha carboxyl group C. methyl group and alpha carboxyl group D. methyl group and hydrogen substituent 64.____These amino acid alphabets signify the amino acids belonging to the acidic group: A. K, R, H B. D, K, L C. D, E D. R, E, Y 65.____Of the ff. Non-polar, aliphatic amino acids, this one contain the pyrolidine ring: A. Methionine C. Isoleucine B. Alanine D. Proline 66.____The ff are pollar amino acids with uncharged R groups: A. Ser, Ala, Trp C. Thr, Gln, Cys B. Lys, Tyr, Gly D. Arg, His, Glu 67.____An aromatic amino acid that possess the indole group: A. phenylalanine C. Tyrosine B. Tryptophan D. Lysine 68.____Amino acids with a positively charged R groups: A. R, H, K B. H, E, G C. E, D, L D. R, E, N 69.____The aromatic amino acids absorbs UV light maximally at 280 because of this part of their structure: A. the α amino group C. The ring structures B. the α carboxylic group D. The methyl substituent Label the number items in the graph; choose your answers from the given choices: Place your answers on the spaces given for each of the corresponding numbers. 70. C

71. A

72. F

73. B

74. D

75. E

A. 1st COOH group titrated, then NH3 group B. Tow buffer zones C. Isoelectric point D. positively charged ion E. negatively charged ion F. NH2 group titrated 76.____An amino acid has a point of a 3.5. which of the following could be correctly inferred about this information? A. the amino acid could be considered to be a basic amino acid B. at pH of 3.5, the amino acid will exist as a zwitterion C. maximum buffering effect of the amino acid is exhibited at pH 3.5 D. when electrophoresed at a pH of 8.6 the amino acid will move towards the cathade 77.____The type of bonds that stabilizes the quaternary structure of polypeptides: A. non-covalent and covalent bonds B. hydrogen bonds and ionic interactions C. hydrophobic and salt interactions D. electrostatic and hydrogen bonds 78.____The native conformation of a polypeptide may first be achieved upon assumption level of protein structure: A. primary B. Secondary C. Tertiary D. Quaternary 79.____The a helix and beta pleated sheet represent which level of protein A. primary B. Secondary C. Tertiary D. Quaternary 80. 81. 82. 83. 84.

C C A D B

85.____Guanylate is composed of: A. guanine + ribose B. guanine + deoxyribose +PO4

C. Guanine + ribose +PO4 D. Guanine + PO4

86.____The bond between cytosine and ribose: A. O-glycosidic bond C. Peptide bond B. N-glycosidic bond D. Hydrogen bond 87.____A nucleotide that serves as a second messenger: A. GMP C. NAD+ B. FAD D. cAMP 88.____A nucleotide used as a coenzyme in oxidation-reduction reactions: A. NAD+ C. cGMP B. FAD D. AMP 89.____True of the functions of nucleic acids: A. for storage of genetic information B. for transfer of genetic information C. used for recombination technology D. all of the choices 90. _____Direction of oligonucleotides: A. 5’ to3’ B. 3’ to 5’ C. 3’ to 2’

D. 2’ to 3’

91. _____These molecules form the backbone of DNA: A. adenine + ribose C. Ribose + PO4 groups B. deoxyribose + PO4 group D. Thymine + PO4 92._____The base that pairs with adenine in RNA: A. guanine C. Uracil

B. cytosine

D. Thymine

93._____The model of DNA as described by Watson & Crick: A. B-DNA C. Z-DNA B. A-DNA D. cDNA 94._____The atoms of adenine directly or indirectly involved in the H-bonds between the base pairs A-T: A. N9 & C4 C. N3 & C2 B. N1 & C6 D. N7 & C5 95._____The atoms of cytosine directly or indirectly involved in the H-bond between the base pair G-C: A. C6, C5 & C4 C. N1, C2 & C6 B. N1, C2 & N3 D. N3, C4 & C2 96._____An RNA that possess a 7 methylguanosine cap at the 5’ end: A. tRNA C. mRNA B. rRNA D. snRNA 97._____The type of histone that forms part of the nucleosomes, EXCEPT: A. H1 B. H2A C. H2B D. H3 98._____A type of RNA that assumes a cloverleaf appearance possessing A. mRNA B. rRNA C. snRNA D. tRNA 99._____This ribosomal RNA is found in prokaryotes: A. 28S B. 16S C. 5.8S 100._____The large subunit of mammalian rRNA: A. 70S B. 80S C. 60S

D. 18S D. 50S