BIOCHEM EXAM RATIONALE IPS1

Increase the unsaturated fatty acids

Which of the following will specifically increase the fluidity of the cell membrane?

A. Decrease in temperature

B. Increase the unsaturated fatty acids

C. Increase the saturated fatty acids

D. Removal of cholesterol

Primary active transport

Transport of solute against its concentration gradient:

A. Primary active transport

B. Facilitated diffusion

C. Simple diffusion

D. Osmosis

Has an l-configuration

Which of the following is not true about glycine?

A. Achiral

B. Aliphatic

C. Simplest amino acid

D. Has an l-configuration

I, II, III

Acidic amino acids:

I. Are negatively charged at neutral pH

II. Are ionizable amino acids

III. Include glutamic acid and aspartic acid

IV. Form H bonds

A. I, II, III, IV

B. I, IV

C. II, III, IV

D. I, II, III

Facilitated diffusion is saturable, meaning, the carriers may be fully occupied.

Which of the following statements differentiates simple passive diffusion from facilitated diffusion?

A. Facilitated diffusion is saturable, meaning, the carriers may be fully occupied.

B. Facilitated diffusion is an active process.

C. Facilitated diffusion moves against concentration gradient. D. Facilitated diffusion is not a carrier-mediated transport process.

Primary

Which of the following protein structure is resistant from denaturation?

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

Mitochondrion

The organelle which has its own DNA and the site of energy-yielding oxidation reactions:

A. Nucleus

B. Golgi Apparatus

C. Endoplasmic Reticulum

D. Mitochondrion

Glutathione peroxidase

Deficiency of Se is associated with decreased efficiency of:

A. Urease

B. Nitrate reductase

C. Glutathione peroxidase

D. Superoxide dismutase

Transferases

These are enzymes that facilitate group transfer:

A. Oxidoreductases

B. Transferases

C. Hydrolases

D. Ligases

[P]

Which of the following factors can affect the rate of reaction held by enzymes?

A. Temperature

B. pH

C. [P]

D. [S]

AT requires energy; FD does not.

What is the difference between active transport (AT) and facilitated diffusion (FD)?

A. AT requires protein carriers; FD does not.

B. AT requires energy; FD does not.

C. AT requires a concentration gradient; FD does not.

D. AT requires a membrane; FD does not.

Enzyme A has a higher Vmax

A substrate has the same affinity towards enzyme A and B. However, when all other conditions are identical, a higher molar concentration of the product is seen when enzyme A is used. This means that compared to enzyme B:

A. Enzyme A has a higher Km

B. Enzyme A has a lower Km

C. Enzyme A has a higher Vmax

D. Enzyme A has a lower Vmax

A crude measure of the affinity between the enzyme and substrate

What is the significance of Km?

A. A crude measure of the affinity between the enzyme and substrate

B. Tells how fast the enzyme can generate product under saturating substrate conditions

C. Measurement of the relationship between the enzyme concentration and substrate concentration

D. Measurement of the relationship between V0 and pH

X axis

The Lineweaver-Burk plot of noncompetitive inhibition shows lines that intersect on the _____.

A. X axis

B. Y axis

C. Origin

D. No intersection

Cytosol

In what cell component does fatty acid synthesis occur?

A. Lysosome

B. sER

C. Cytosol

D. Mitochondrion

Ceruplasmin

In diagnosing patients with suspected Cu poisoning, which enzyme must be monitored?

A. CK

B. Amylase

C. Ceruplasmin

D. Lipase

Which of the following is not found in the cytoplasm?

A. Cytosol

B. Inclusions

C. Mitochondrion

D. Plasma membrane

Asparagine

Ketogenic amino acids may include all of the following, except: A. Phenylalanine

B. Isoleucine

C. Lysine

D. Asparagine

Basic

Lysine and arginine amino acids are ____.

A. Acidic

B. Neutral

C. Nonpolar

D. Basic

Arginine

This amino acid is considered as a semi-essential amino acid in humans.

A. Lysine

B. Tryptophan

C. Lysine

D. Arginine

Primary

This structure of peptides refers to the order of amino acids in the polypeptide chain/s:

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

Elastin

A fibrous protein that is important component of arterial blood vessels and ligaments.

A. Keratin

B. Collagen

C. Elastin

D. Fibronectin

Quaternary

Protein present in hemoglobin has a structure known as:

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

Val

In sickle cell anemia, Glu is replaced by which amino acid?

A. Val

B. Lys

C. Ile

D. Ala

An amino acid

Which component is not part of a nucleotide?

A. A nitrogen-containing base

B. A monosaccharide

C. An amino acid

D. A phosphate group

Uracil

Which base is found in DNA or RNA, but not both?

A. Uracil

B. Adenine

C. Cytosine

D. Guanine

10

Compute for the isoelectric point of lysine: pK1 = 2.2, pK2 = 9.2, pK3 = 10.8

A. 10

B. 6.5

C. 5.7

D. 10.7

mRNA

Which type of RNA is a template for protein synthesis?

A. mRNA

B. tRNA

C. rRNA

D. dDNA

Glycine

All amino acids found in proteins are in L configuration except:

A. Leucine

B. Thymine

C. Threonine

D. Glycine

It is globular in shape

Which does not correctly describe collagen?

A. It is a structural protein.

B. It is the most abundant fibrous protein

C. It is globular in shape

D. It is found in all tissues and organs

The peptide contains a side chain with a secondary amino group.

Which one of the following statements concerning the peptide shown below is correct? Val-Cys-Glu-Ser-Asp-Arg-Pro

A. The peptide contains asparagine.

B. The peptide contains a side chain with a secondary amino group.

C. The peptide contains a thioether side chain.

D. The peptide cannot form an internal disulfide bond.

Monosaccharide + Base

What is a nucleoside?

A. Monosaccharide + Base

B. A polymer of nucleotides

C. monosaccharides ribose and deoxyribose

D. monosaccharide + a base + phosphate

TAU

Which sequence is not possible?

A. GAGA

B. TAU

C. TATA

D. TGA

control muscle contractions

What is the function of myosin in the human body?

A. as connective tissue found in tendons, bone, cartilage, and blood vessels

B. control muscle contractions

C. stores iron in the liver

D. stores O2 in tissues

Glycosidic bond

Which of the following bonds provides attachment of the sugar to the N-base?

A. H Bond

B. PD Bond

C. Glycosidic bond

D. Peptide bond

Disulfide bond

What is the strongest type of interaction between two cysteine amino acids in a protein?

A. Hydrogen bonding

B. London dispersion forces

C. Disulfide bond

D. Electrostatic interactions

Denaturation

What is the process of altering the shape of a protein without breaking the amide bonds that form the primary structure?

A. Hydrolysis

B. Competitive inhibition

C. Denaturation

D. Oxidation

3

How many chirality centers are in leu-enkephalin (structure shown)?

A. 1

B. 2

C. 3

D. 4

The primary structure of a protein

What is the particular sequence of amino acids of a protein that are joined together by peptide bonds called?

A. The primary structure of a protein

B. The tertiary structure of a protein

C. The secondary structure of a protein

D. The quaternary structure of a protein

Only statement 1 is correct.

Evaluate the two statements:

I. Amino acid [Q] has a nonionic polar side chain.

II. It is also classified as an aliphatic amino acid with hydroxyl group.

A. Only statement 1 is correct.

B. Only statement 2 is correct.

C. Both statements are correct.

D. Both statements are incorrect.

Tryptophan

This amino acid contains the indole functional group.

A. Histidine

B. Arginine

C. Tryptophan

D. Proline

Secondary

Helical formation of helix is a characteristic of what protein structure?

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

Peptide bonds

The main mode of linkage in primary protein structure is:

A. Hydrogen bonds

B. Peptide bonds

C. Salt bridges formation

D. Covalent bonds

DNA

Hydrogen atom at 2' of the ribose ring indicates that the nucleic acid is:

A. RNA

B. DNA

C. ATP

D. ADP

Cytosine and Guanine

Which of the following base pairs is bound by a triple bond?

A. Adenine and Thymine

B. Guanine and Thymine

C. Adenine and Cytosine

D. Cytosine and Guanine

Tertiary

The chromatin structure is an example of _____ structure.

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

Residue

Each amino acid in the chain is called:

A. Carboxyl

B. Amino

C. Residue

D. Peptide

Overlapping

This is not a feature of a genetic code:

A. Degenerate

B. Unambiguous

C. Overlapping

D. Universal

Prion

These cause neurodegenerative diseases to cause improper folding of proteins:

A. Chaperones

B. Protein denaturation

C. Domain

D. Prion

Has freedom of rotation

Which among the following is not a characteristic of a peptide bond?

A. Has freedom of rotation

B. Side chains are free to rotate on either side

C. Partially double bond

D. Rigid and planar

DNA Polymerase I

5'-3' exonuclease activity is exhibited by what type of DNA polymerase?

A. DNA Polymerase I

B. DNA Polymerase II

C. DNA Polymerase III

D. DNA Polymerase IV

Helicase

Unzipping of dsDNA is catalyzed by:

A. Polymerase

B. Helicase

C. Topoisomerase

D. Ligase

a point mutation

Which type of mutation is expressed when a DNA sequence changes from GGA TCA CCG GAA.... to GGA TCC CGG....?

A. a deletion mutation

B. an insertion mutation

C. a point mutation

D. All of the above

Transversion

A purine that substitutes for a pyrimidine and vice versa is what type of point mutation?

A. Transition

B. Transversion

C. Translocation

D. Transmission

GCUAACUG

Which of the following is the complementary RNA strand of the sequence CGATTGAC?

A. CAGTTAGC

B. GCUAACUG

C. TCUAACTG

D. GCTAACTG

Replication fork

The point where unwinding occurs in DNA is:

A. Replication fork

B. Replication bubble

C. Leading strand

D. Lagging strand

Proteostatis

This is defined as the continual maintenance of active set of cellular proteins required under a given set of conditions:

A. Amyloidoses

B. Homeostasis

C. Proteostasis

D. Collagenopathies

TRUE; TRUE

Nascent proteins are non-functional. Native proteins are functional.

A. TRUE; FALSE

B. FALSE; TRUE

C. TRUE; TRUE

D. FALSE; FALSE

Hsp60

These are also known as cage-like chaperones in eukaryotes: A. GroEL

B. Hsp70

C. PDI

D. Hsp60

Addition of 7-methylguanosine cap at the 3' end

In post-transcriptional modifications of mRNA, the following are observed, except:

A. Addition of 7-methylguanosine cap at the 3' end

B. Addition of Poly(A) tail

C. RNA Splicing

D. None of the above

All of the choices

Agents that promote protein denaturation:

A. Heat

B. UV Radiation

C. Strong Acids

D. All of the choices

Alzheimer's Disease

Increased levels of b-amyloid is critical in aggravating:

A. Huntington's Disease

B. Alzheimer's Disease

C. b-Thalassemia

D. Parkinson's Disease

metabolism

Which is the sum of all of the chemical reactions that take place in an organism?

A. anabolism

B. catabolism

C. metabolism

D. citric acid cycle

Tertiary

Complete 3D conformation:

A. Primary

B. Secondary

C. Tertiary

D. Quaternary

phosphorylation

The addition of a phosphate group to ADP, forming ATP is an example of what type of reaction?

A. hydration

B. hydrolysis

C. phosphorylation

D. reduction

E. decarboxylation

I, III

Which of the following correctly describe/s collagen?

I. Triple helix

II. In every 3rd amino acid residue, proline is observed

III. Gly-X-Y sequence

A. I, II, III

B. I, II

C. I, III

D. II, IV

Kinks

What is the essence of having P in the structure of collagen?

A. Flexibility

B. Integrity

C. Kinks

D. Rigidity

I, II, III

Which of the following cofactor/s is/are needed in the hydroxylation of proline and lysine?

I. Iron

II. Oxygen

III. Vitamin C

A. I, II, III

B. I, III

C. I, II

D. II, III E. III only

1

How many reactions in the citric acid cycle generate FADH2? A. 0

B. 1

C. 2

D. 3

E. 4

Elastin

This protein is found in lungs with rubber-like properties:

A. Hemoglobin

B. Myoglobin

C. Keratin

D. Elastin

Myoglobin

A storage protein of oxygen:

A. Hemoglobin

B. Myoglobin

C. Keratin

D. Elastin

Carboxyhemoglobin

CO poisoning is caused by increased levels of:

A. Methemoglobin

B. Carboxyhemoglobin

C. Myoglobin

D. Hemoglobin

glucose to pyruvate.

Glycolysis converts _____

A. polysaccharides to glucose.

B. glucose to pyruvate.

C. fatty acids to thioesters

D. amino acids to urea.

glucose

Which is not one of the three major products that are formed in glycolysis?

A. glucose

B. ATP

C. NADH

D. pyruvate

It has a hyperbolic shape in its oxygen dissociation curve

True statements concerning hemoglobin, except:

A. It has a hyperbolic shape in its oxygen dissociation curve

B. It has 4 polypeptide subunits

C. It is a quaternary structure type of protein

D. All are correct

pyruvate to acetyl CoA

Which process requires the coenzyme NADH?

A. glucose to pyruvate

B. pyruvate to acetaldehyde

C. pyruvate to lactate

D. pyruvate to acetyl CoA

low carbohydrate diet

Which factors increase the rate of gluconeogenesis?

A. high glycogen reserves

B. low carbohydrate diet

C. high carbohydrate diet

D. low oxygen concentration

in the inner membrane of mitochondria

Where does the electron transport chain process take place? A. in the inner membrane of mitochondria

B. in the outer membrane of mitochondria

C. in the intermembrane space of mitochondria

D. in the matrix of mitochondria

are catabolized to pyruvate or an intermediate in the citric acid cycle.

Glucogenic amino acids _____

A. are converted to acetyl CoA.

B. are converted to the thioester acetoacetyl CoA.

C. are catabolized to pyruvate or an intermediate in the citric acid cycle.

D. can be converted to ketone bodies

Inner mitochondrial membrane

The electron transport chain (ETC) is the final common pathway by which electrons derived from the different fuels of the body flow to oxygen. Where does ETC occurs?

A. Outer mitochondrial membrane

B. Cytosol

C. Golgi complex

D. Inner mitochondrial membrane

Conversion of amino acids to keto acids

Which of the following is called transamination?

A. Conversion of amino acids to hydroxyl acids

B. Conversion of amino acids to keto acids

C. Loss of ammonia from amino acids

D. Formation of ammonium salts from ammonia

Catabolic

The energy producing reaction:

A. Metabolic

B. Catabolic

C. Anabolic

D. Amphibolic

The regulated reactions are also the irreversible reactions.

Which one of the following statements concerning glycolysis is correct?

A. The conversion of glucose to lactose requires the presence of oxygen.

B. Hexokinase is important in hepatic glucose metabolism only in the absorptive period following consumption of a carbohydrate-containing meal.

C. Fructose 2,6-bisphosphate is a potent inhibitor of phosphofructokinase.

D. The regulated reactions are also the irreversible reactions.

Acetyl CoA

. It is the building block of essential fatty acids.

A. Malonyl CoA

B. Phosphoribosyl pyrophosphate

C. Acetyl CoA

D. HMG CoA

B cell.

Insulin promotes the storage of fat and glucose in specialized target cells. What pancreatic cell type is responsible for secreting this hormone?

A. A cell.

B. B cell.

C. D cell.

D. F cell

Asparagine

Ketogenic amino acids may include all of the following, except: A. Phenylalanine

B. Isoleucine

C. Lysine

D. Asparagine

III, IV

Which of the following biochemical pathways occur in the cytoplasm?

I. Decarboxylation of Pyruvate

II. Krebs Cycle

III. HMP Pathway

IV. Fatty Acid Synthesis

A. I, II

B. II, III

C. I, III

D. III, IV

glycolysis

The process where 6-carbon glucose molecule is split into two molecules of pyruvic acid.

A. glycolysis

B. citric acid cycle

C. calvin cycle

D. TCA

ATP

A molecule that carries energy within cells.

A. NADH

B. ATP

C. NADPH

D. glucose

oxygen

Which of following is not a product of citric acid cycle?

A. carbon dioxide

B. NADH

C. FADH2

D. oxygen

Fermentation

If oxygen is not present, this step will happen after glycolysis. A. citric acid cycle

B. ETC

C. Fermentation

D. Glycogenesis

Carbon dioxide and water

What are the products of aerobic respiration?

A. Acetyl CoA and oxygen

B. Carbon dioxide and water

C. Lactic acid

D. Ethanol

glucose and oxygen

What are the reactants in the equation for cellular respiration? A. oxygen and lactic acid

B. carbon dioxide and water

C. glucose and oxygen

D. water and glucose

mitochondria

Where does the Krebs Cycle take place?

A. mitochondria

B. chloroplast

C. cytoplasm

D. nucleus

Glycolysis > Krebs cycle > ETC

Which is the correct order of the steps of cellular respiration? A. Glycolysis > Krebs cycle > ETC

B. Glycolysis > ETC > Krebs cycle

C. Krebs cycle > ETC > Glycolysis

D. ETC > Glycolysis > Krebs cycle