Module 2: Biochemistry - Practice Questions - PACOP Blue

What two enzymes are used to bypass the pyruvate kinase reaction of glycolysis?

I. pyruvate carboxylase

II. PEP carboxykinase

III. Fructose biphosphatase

IV. Glucose-6-phosphate

A. I & II D. II & IV

B. III & IV E. II & III

C. I &III

A

Which of the following includes the main goals of Pentose Phosphate Pathway?

I. produce ribose-5-phosphate for nucleotide synthesis

II. produce NADPH and NADP for oxidoreductive biochemical synthesis

III. to interconvert pentoses and hexoses

A. I & II D. I, II & III

B. II & III

C. I & III

D

Which of the following statements is/are true regarding the secondary structure of

nucleic acids?

I. Guanine forms base pairs with cytosine via 2 hydrogen bonds

II. The B form of the DNA is the most common in biological systems

III. The breaking of H-bonds caused by high temperature is called melting

A. I,II & III D. I & II

B. I & II E. II only

C. II & III

C

The phospholipid, phosphatidylinositol 4,5-biphosphate forms the potent secondary

messengers inositol triphosphate & diacylglycerol via what enzyme?

A. Phospholipase A D. Phospholipase B

B. Phospholipase C

C. Phospholipase D

B

Which of the following is not true regarding the four enzyme complexes of the electron

transport chain?

A. Complex I is known as the NADH-CoQ Oxidoreductases

B. Complex II is known as Succinate-CoQ Oxidoreductases

C. Complex III is known as Cytochrome Oxidase

D. Complex IV is known as Cytochrome Oxidase

C

Glucose and mannose are epimers at:

A. Carbon 4 C. Carbon 3

B. Carbon 2 D. Carbon 5

B

One important endogenous molecule for synthetic biotransformation of xenobiotics is

glucoronic acid. It is actually the most dominant conjugative biotransformation pathway due to the

readily available source of glucose. It is produce from glucose via:

A. Oxidation at carbon 1 C. Oxidation at carbon 6

B. Oxidation at carbon 2 D. Oxidation at carbon 1 & 6

D

Which of the following is not true about protein structure determination?

A. NMR is the primary means of determining protein structure

B. Protein are difficult to crystallize, a disadvantage of x-ray crystallography

C. An advantage of the use of the NMR is that proteins analyzed are in their natural state

D. Large and very complex proteins can only be analyzed by x-ray crystallography

A

Tertiary structures of proteins are primarily stabilized by

I. H-bonds

II. Hydrophobic interactions

III. Ionic bonds

IV. Disulfide bonds

A. I & III D. I, II& IV

B. II & IV E. II, III & IV

C. I,III & IV

B

In an uncompetitive inhibition of enzymatic action :

A. Inhibitor binds either to the free enzyme or the enzyme substrate complex

B. Lineweaver-Burk plots of the enzyme alone (control) & the enzyme + inhibitor are

parallel to each other

C. The apparent Km is raised

D. The Vmax is unaffected

B

Which biomolecule is not considered a biopolymer?

A. Proteins D. Nucleic acids

B. Lipids E. Fat

C. Carbohydrates

B

It is regarded as the universal biological energy currency

A. Adenosine triphosphate C. Uncouplers

B. Guanosine triphosphate D. Calories

A

This is the final electron receptor of the electron transport chain

A. Complex I C. Complex V

B. Complex II D. Complex IV

???

The most accepted hypothesis regarding oxidative phosphorylation is

A. Chemical coupling D. Lock and Key Theory

B. Conformational coupling E. Diffusion

C. Chemiostatic hypothesis

C

This is a quantitative study of the energy transformationsin the living cell

A. Bioenergetics C. Proteonomics

B. Thermodynamics D. Metabolomics

A

Which of the following hormones promotes rapid glycogenolysis in both liver and muscle

A. ACTH C. Epinephrine

B. Glutemine D. Prolactin

C

Which vitamin can be used in the management of hyperlipidemia?

A. Thiamine C. Niacin

B. Riboflavin D. Panthotenic acid

C

Bond between 2 amino acids

A. Glycosidic bond C. Peptide Bond

B. N-glycosyl linkage D. Hydrogen bond

C

Beta oxidation of fatty acids occurs in the

A. Cytosol C. Endoplasmic reticulum

B. Mitochondria D. Ribosomes

???

The pentose phosphate pathway occur in the ________ of the liver, muscle and kidney.

A. cytosol C. endoplasmic reticulum

B. mitochondria D. ribosomes

C

The isoelctric point is the

A. pH where the alpha amino acid exist in its negatively charged form

B. pH wherein the amino acid exist in zwitterionic form

C. Temperature at which the amino acid denatures

D. Pressure at which the amino acid hydrolyzes

B

This is the only optically inactive amino acid

A. methionine C. Citrulline

B. Lysine D. glycine

D

This level of protein structure is applicable only to those have several subunits

A. Primary C. Tertiary

B. Secondary D. Quaternary

D

Arginine is the only metabolite of the urea cycle that does not accumulate because

A. It is readily excreted

B. It is used up by the body for protein synthesis

C. There is no known deficiency in the enzyme that catabolizes it

D. It can ve acquired from food

B

This is the genetic condition characterized by deficiency of the enzyme branched chain

alpha-keto acid dehydrogenase

A. Maple syrup disease C. Kwashiorkor

B. Hartnup disease D. Marasmus

A

These are compounds related to cerebrosides that contain sphingsine, long chain fatty

acids, hexoses (usually galactose or glucose) and neuramic acid

A. cephalins C. cytolipins

B. gangliosides D. lecithins

B

This enzyme catalyzes the conversion fructose-6-P to fructose-1,6-bis-P

A. hexokinase C. PFK

B. pyruvate kinase D. glyceraldehyde phosphate dehydrogenase

???

Which of the following is called transamination?

A. Conversion of amino acids to hydroxyl groups

B. Conversion of amino acids to keto acids

C. Loss of ammonia from amino acids

D. Formation of ammonium salts from ammonia

B

The sugar involved in the DNA

A. ribose C. deoxyribose

B. pentose D. xylose

C

Thisis the reason why blood AB is considered as the universal recipient.

A. It is the most common among the ABO blood types

B. Blood type AB has neither A nor B substances

C. Blood type AB has either anti-A nor anti-B antibodies

D. All of the above

C

Which one is true regarding the structures of lipids?

A.Eicosanopentanoic acid is a saturated fatty acid

B. They may exist as esters of cholesterol when they are enclosed in very low density

C. Linoleic acid is an omega-3 fatty acid

D. Capric acid contains 12 carbons

C

This is the product of basic hydrolysis of fats and oils

A. fatty acid C. soap

B. triacylglycerol D. detergent

C

The group of lipids is considered amphipathic

A. sterols C. trans-fatty acids

B. fatty acids D. phospholipids

???

Which properly describes a liposome?

A. It is a hollow sphere-like structure composed of a lipid bilayer enclosing an

aqueous cavity

B. It is a lipid structure wherein the hydrophobic chains of the fatty acids are

sequestered at the core of the sphere with virtually no water in the hydrophobic interior

C. It is a lipoprotein integrated in the phosphopolipid bilayer of the cell membranes

D. It is a hollow sphere-like structure composed of a lipid monolayer enclosing a

hrdrophobic cavity

A

It is the building block of essential fatty acids

A. Malonyl CoA C. Acetyl CoA

B.phosphoribosyl pyrophosphate D. HMG CoA

C

The digestion of carbohydrates begins in the________.

A. mouth C. small intestine

B. stomach D. duodenum

A

Cellular elements of the blood devoid of nucleus

A. RBC C. thrombocytes

B. WBC D. all of the above

A

Conjugated proteins which are a combination of amino acids and carbohydrates

A. nucleoproteins C. phosphoproteins

B. glycoproteins D. chromoproteins

B

Glucose is normally absent in the urine because kidneys normally completely reabsorb all

glucose. Which of the following is true?

A. Glucosuria confirms diabetes mellitus

B. Glucosuria necessarily means hyperglycemia

C. Glucosuria is solely attributed to insulin problem

D. Glucosuria may occur in other disease states

D

Wernicke-Korsakoff syndrome which can cause acute confusion, ataxia and

opthalmoplegia, can be treated with which of the following?

A. riboflavin C. thiamine

B. ascorbic acid D. pantothenic acid

C

This is the major excretory product of purine nucleotides

A. inosine monophosphate C. methylmalonyl CoA

B. uric acid D. tetrahydrofolate

B

This is the phenomena of renaturation of nucleic acid after it has been subjected to high

then to room temperature

A. Hydrolysis C. annealing

B. Polymerase chain reaction D. hybridization

C

This is the base sequence for the start codon

A. UAG C. AUG

B. UGA D. UAA

C

This feature of bacterial cells confers selectivity of antibacterial agents targeting protein

synthesis to the bacteria and not to the host cell.

A. mRNA C. lack of cell wall

B. 40s ribosomal subunit D. 30s ribosomal subunit

D

This is also known as the RNA-directed DNA polymerase

A. RNA polymerase II C. DNA polymerase alpha

B. Reverse transcriptase D. DNA polymerase II

B

What essential amino acid is used in the synthesis of niacin?

A. Tyrosine C. tryptophan

B. Methionine D. Phenylalanine

C

The cellular particles are often referred y their sedimentation coefficient value, for example

70s ribosomes that is expressed in terms of 10 -13 seconds. The abbreviation "s" stands for

A. subunit C. Svedberg

B. Seconds D. None of the above

C

The best known building blocks of RNA and DNA are

A. purinase C. fatty acids

B. pyrimidines D. a and b

D

The following are pathological constituents of urine, except:

A. glucose C. creatinine

B. albumin D. blood

C

Glucose and galactose differ only in the configuration of their hydroxyl group at carbon 4.

Glucose and galactose are

A. diastereomers C. epimers

B. enantiomers D. anomers

C

The chemical representation shows the most stable conformation of hexoaldopyranoses

A. Fischer projection C. Haworth Formula

B. Boat conformation D. Chair conformation

D

It is the most abundant hexose inside the body

A. L-glucose C. L-ribose

B. D-glucose D. D ribose

B

Upon hydrolysis sucrose yields

A. glucose and galactose C. fructose and glucose

B. xylose and glucose D. 2 glucose units

C

This is the process of biosynthesis of glucose from non-carbohydrate precursors

A. glycolysis C. gluconeogenesis

B. glycogenesis D. glycogenolysis

C

Which is most likely the effect of insulin in glucose metabolism

A. It promotes lipolysis in adipose tissue

B. It promotes exocytosis of glucose transporters in the skeletal muscles

C. Activates protein kinase A which eventually leads to inactivation of pyruvate kinase

D. It promotes the hormonal role of glucagon in glucose metabolism

B

The activation of plasminogen requires

A. NaOH C. acetic acid

B. bicarbonate D. HCl

D

Glucose,fructose and galactose all have the same chemical formula C6H12O6, through

this information, we can conclude that these substances are

A. Anomers C. enatiomers

B. Epimers D. isomers

D

The end product in the hydrolysis of glycogen is

A. galactose C. glucose

B. mannose D. arabinose

C

Ketoses can be differentiated from aldose by this test

A Molisch's test C. Seliwanoff's test

B. Benedict's test D. Tollen's test

C

Which of the following statements is/are correct?

I.The difference between intake and output of nitrogenous compounds is known as

hydrogen balance

II. In a healthy adult, nitrogen balance is in equilibrium when intake equals

output

III. Positive nitrogen balance ocuurs when dietary intake is less then excretion

of nitrogenous compounds

IV. Negative nitrogen balance results when there is too much protein intake

A. 3 only D. 2 & 4

B. 1 & 2 E. 1-4

C. 1 & 3

B

The formation of purple ring at the junction of the acid and sugar layers in the Molisch's

test detects the presence of ___________.

A. carbohydrates C. lipids

B. proteins D. nucleic acids

A

The observance of a red colored solution in Seliwanoff's test detects the presence of

______________.

A. Aldoses C. Pentoses

B. Ketohexoses D. Saccharides

B

This test distinguishes between reducing sugar monosaccharides and reducing

disaccharides based on the difference in the rate of reaction.

A. Barfoed's test C. Osazone test

B. Benedict's test D. Mucic acid test

A

In xanthoproteic test, proteins with aromatic amino acids undergo _________ to give an

intense yellow colored solution in alkaline media.

A. condensation C. nitration

B. Acetylation D. oxidation

C

Biuret test forms ______ colored complex with cupric ion in basic solutions of compounds

with 2 or more peptide bonds.

A. green C. violet

B. red D. yellow

C

When starches are heated they produce

A. Sugars C. dextrin

B. Glycogen D. disaccharides

CC

The principal end product of protein metabolism

A. carbon dioxide C. hippuric acid

B. ammonia D. urea

D

Myoglobin and hemoglobin possess a cyclic tetrapyrole, heme, as a prothetic group. Which

of the following is found centrally located in the heme?

A. Mg C. Fe

B. Al D. P

C

The following are the components of DNA nucleosides except

A. phosphoric acid C. adenine

B. sugar D. cytosine

A

The enzyme decarboxylase is an example of _________ enzyme.

A. hydrolase C. racemase

B. ligase D. lyase

D

The spontaneous isomerization of two stereoisomers in aqueous solution that causes

specific rotation is known as

A. zwitterions rotation C. mutarotation

B. micelle rotation D. stereorotation

C

Which of the following is a polysaccharide?

A. dextrose C. lactose

B. dextran

D. sucrose

B

The substance that is isolated from the brain and produces fatty acid, galactose and

sphingosine upon hydrolysis is known as

A. sterols C. glycolipids

B. phospholipids D. saponins

C

Which of the following is NOT a hydrolyzed product of lecithins?

A. fatty acid C. phosphoric acid

B. glycerol D. sphingosine

D

Albumin is an example of a

A. simple protein C. derived protein

B. conjugated protein D. hydrolyzed protein

A

This is the product of the complete reduction of oxygen

A. water C. hydrogen peroxide

B. superoxide anions D. hydroxyl radicals

A

Which is not a B-complex vitamin?

A. folic acid C. riboflavin

B. nicotinic acid D. ascorbic acid

D

Rotation of polarized light is caused by the solution of all the following amino acids except

A. alanine C. leucine

B. glycine D. valine

B

What test can be used to differentiate galactose from lactose?

A. Benedict's test C. Barfoed's test

B. Iodine test D. Mucic acid test

C

Alpha-naphtol reaction is also known as

A. Molisch's test C. Phenylhydrazine test

B. Ninhydrin test D. Fehling's test

A

81. Which of the following is not about PKU?

A. It is a disease usually characterized by metal abnormalities

B. A high concentration of phenylpyruvic acid is found in the urine

C. It occurs due to excessive secretion of phylalanine hydroxylase enzyme

D. A Guthrie test is normally used to detect it

C

Sweet taste of a compound is generally attributed to

A. presence of H ions C. presence of cations and anions

B. presence of OH ions D. presence of alkaloids

B

The rate of hydrolysis depends on

I. pressure

II.pH of the solution

III. Temperature

A. I only C. II & III only

B. I & II only D. I, II & III

C

Which of the following is NOT recommended to treat hypoglycemia induced by acarbose?

A. dextrose C. glucagon

B. table sugar D. glucose

B

Which of the following is normally NOT found in the bacterial bit present in human cells?

A. golgi body C. lysosome

B. mitochondria D. endoplasmic reticulum

B

This term refers to an intact enzyme with a bound co-facor.

A. holoenzyme C. zymogen

B. apoenzyme D. prosthetic group

A

The color of the skin, hair and eyes is due to a pigment called

A. cytochrome C. keratin

B. melanine D. heparin

B

Serotonin is synthesized from this amino acid

A. tryptophan C. tyrosine

B. threonine D. alanine

A

Keratin in hair and horny tissue, elastin in tendons and arteries, and collagen in skin and

tendons belong to what type of simple proteins?

A. glutelins C. protamines

B. histones D. albuminoids

D

Nucleosides upon hydrolysis will yield

A. adenine + phosphate C. histones + ribose

B. quinine + phosphate D. cytosine + ribose

D

Which of the following is/are true about lysozyme?

I. It is generally known as the power house of the cell.

II.It helps in the removal of damaged cell

III. It contains a bactericidal agent such as lysozyme that kills bacteria before it

damages the cell.

A. I only C. II & III only

B. I & II only D. I, II & III only

C

Which of the following is the rate limiting step in synthesis of RBC?

A. availability of pre-erythrocytes C. oxygen transport capacity

B. availability of hemoglobin D. presence of erythropoietin

C

Which of the following helps in absorption of vitamin B12 ?

A. erythropoietin C. hemoglobin

B. intrinsic factor D. apoferritin

B

Which of the following factors affect the solubility of solutes?

I. temperature II. pH III. Common ion effects

A. I only C. II & III only

B. I & II only D. I, II & III

D

Which of the following factors affect the protein binding drugs?

I. pregnancy II. Hypoalbuminemia III. Uremia

A. I only C. II & III only

B. I & II only D. I, II & III

D

Some serum enzymes are used in clinical diagnosis. Which of the following enzyme/s may

be used to diagnose myocardial infarction?

I.gamma-glutamyl transpeptidase

II. AST or SGOT

III. Creatine phosphokinase

IV. Lactate dehydrogenase

A. III only C. I,II & III

B. II & IV only D. II,III & IV

D

Which of the following test is specific for amino acids and free amino group?

A. Biuret test C. Ninhydrin test

B. Hopin's cole test D. Xanthoproteic test

C

The following sugars are aldohexoses except

A. fructose C. glucose

B. galactose D. mannose

A

Arrange the following secondary derived proteins from highest to lowest molecular weight.

A. peptides>peptones>proteoses C. proteoses>peptones>peptides

B. proteoses>peptides>peptones D. peptones>proteoses>peptides

C

Is the sum total of all activities directed towards the maintenance of life

A. catabolism D. photosynthesis

B. anabolism E. fermentation

C. metabolism

C