PART 2: mixed topics

Question 1

Cyanide poisoning is fatal. This is because cyanide has this effect of the electron transport chan:

Answer 1

inhibits cytochrome oxidase

Question 2

The precursor of the sugar-phosphate moieties in the de novo synthesis of both purine and primidine nucleotide is

Answer 2

ribose 5 phosphate

Question 3

The highest reservoir of calories in muscle tissue is

Answer 3

proteins

Question 4

Deficiency in the intake of carbohydrates and fats can lead to:

Answer 4

increase protein requirements

Question 5

Gluconeogenesis is the major source blood sugar during _________

Answer 5

prolonged fasting

Question 6

The receptor involved in the G-protein coupled signal transduction pathway:

Answer 6

Beta-adrenergic receptor

Question 7

This is the mechanism of action by which PENICILLIN kills bacterial cells:

Answer 7

it covalently binds to the active site of the enzyme for cell wall synthesis

Question 8

TRUE of Vitamin K

Answer 8

it functions as a cofactor to carboxylase that acts on glutamate residues of clotting factor precursors proteins

Question 9

Kwashiorkor occurs when there is

Answer 9

lack of calories and protein in diet

Question 10

Cancer can be attributed to mutation in the DNA. A mutation that converts an amino acid codon to a stop codon is

Answer 10

nonsense

Question 11

The process by which a polypeptides destination in the cell is determined by

Answer 11

signal peptides

Question 12

The type of histones: uniquely associated with the linker DNA

Answer 12

H1

Question 13

Cytidine is a _______

Answer 13

nucleoSIDE

Question 14

TRUE about the salvage pathway of purine nucleotide synthesis is correct?

Answer 14

Deficiency of hypoxanthine-guanine phosphoribosyl transferase is the cause of Lesch-Nyan syndrome (overproduction of uric acid)

Question 15

______ is the source of MOST blood glucose during starvation:

Answer 15

alanine

Question 16

An individual who has fasted for more than 24 hours will have increased production of

Answer 16

glutamine and alanine

Question 17

excessive ingestion of raw eggwhite is detrimental because it inhibits this step in extramitochondrial lipogenesis:

Answer 17

formation of malonyl coA

Question 18

Semi-conservative replication of DNA means:

Answer 18

each new DNA strand forms a pair with the template strands

Question 19

Ribosomal RNA contain

Answer 19

The anticodon

Question 20

During RNA replication, which enzyme joins the okazaki fragments?

Answer 20

DNA ligase

Question 21

Familial hypercholesterolemia is due to

Answer 21

deficiency or defective LDL receptors

Question 22

most metabolically active plasma lipid

Answer 22

non-esterified fatty acid

Question 23

Deficiency of lipoprotein lipase will result in a increased plasma level

Answer 23

VLDL

Question 24

needed for transport of long-chain FAs from the cytosol to the mitochondrial matrix

Answer 24

carnitine

Question 25

major enzyme that digest dietary triacylglycerol

Answer 25

pancreatic lipase

Question 26

In the liver cholesterol is mainly disposed by:

Answer 26

being converted to bile acids

Question 27

Immediate source of energy of ATP synthesis

Answer 27

electrochemical gradient

Question 28

the link between the catabolic and anabolic reactions in the energy cycle is

Answer 28

ATP

Question 29

function of pyridoxal phosphate

Answer 29

prosthetic group of transaminases

Question 30

vitamin is solely synthesized by bacteria and is thus absent from all plants

Answer 30

Biotin (B7)

Question 31

This vitamin is required for the synthesis of NTs like epinephrine:

Answer 31

Ascorbic Acid

Question 32

deficiency of this mineral is prevalent among pregnant women living in mountainous areas:

Answer 32

Iodine

Question 33

______ accumulates in carnitine deficiency in humans

Answer 33

odd-numbered fatty acids

Question 34

The regulatory action involves a reversible covalent modification of an enzyme

Answer 34

phosphorylation of Ser hydroxyl on the enzyme

Question 35

BEST explains why oxidation of FADH(2) produces less ATP than NADH

Answer 35

FADH(2) enters ETC via complex II

Question 36

BEST applies to isoelectric pH of a protein

Answer 36

net charge is zero

Question 37

what kind of reaction is interconversion of aldose and ketose?

Answer 37

isomerization

Question 38

The beta pleated sheet of a protein is classified as which level of protein

Answer 38

secondary

Question 39

What is the cause for the lactic acidosis that develops in thiamine deficiency?

Answer 39

conversion of pyruvate to acetyl-coA is blocked

Question 40

collagen is _____ helix

Answer 40

triple helix

Question 41

BEST explains the role of hydrochloric acid in the stomach

Answer 41

denature proteins

Question 42

bond that stabilizes the primary structure of a protein

Answer 42

hydrogen

Question 43

products of the action of salivary amylase on glycogen

Answer 43

maltose

Question 44

A zwiterion is a molecule that contains ________

Answer 44

a cation and anion

Question 45

The anemia that develops in patients on anti-malarial therapy may be due to deficiency of enzymes belong to what metabolic pathway?

Answer 45

hexose monophosphate

Question 46

TRUE of the TATA box

Answer 46

binds RNA polymerase

Question 47

SRS-A, the slow reacting substance of anaphylaxis, is composed of ______

Answer 47

leukotrienes

Question 48

The regulation of cholesterol synthesis primarily occurs at which enzymatic site

Answer 48

3-hydroxy-3methylglutaryl coA reductase

Question 49

What is the major source of reducing equivalents used for fatty acid synthesis

Answer 49

pentose phosphate pathway

Question 50

Patients suffering from familial defect in ApoB 100 have significantly elevated levels of plasma LDLs. The reason for this is

Answer 50

inability of LDL to interact with the LDL receptor

Question 51

What is the pharmacological benefit of the drug Lovastatin?

Answer 51

inhibits HMG-coA reductase

Question 52

What vitamin combines with the opsin to form the visual pigment in the eye?

Answer 52

vitamin A

Question 53

the cause of muscle fatigue following vigorous exercise

Answer 53

accumulation of lactate

Question 54

an intermediate of pyrimidine biosynthesis is common to the urea cycle

Answer 54

carbomyl phosphate

Question 55

Function of non-sense codons

Answer 55

they may be used in the cell as termination signals

Question 56

Phase of protein synthesis does the release of newly synthesized polypeptide from the ribosome take place

Answer 56

termination

Question 57

directs the polypeptides ultimate destination in the cell

Answer 57

signal peptides

Question 58

What is the primary action of methotrexate, a chemotherapeutic agent?

Answer 58

displaces cells of folate

Question 59

First reaction in the metabolism of all sugars

Answer 59

phosphorylation

Question 60

site on the operon is the site of RNA polymerase binding

Answer 60

promoter

Question 61

What is the cellular site of synthesis of messenger RNA?

Answer 61

ribosome

Question 62

BEST applies to transfer RNA

Answer 62

exists in at least 20 different forms

Question 63

Biological function of DNA synthesis

Answer 63

assures viability of the specie

Question 64

the enzymes in replication that functions as proof-reading device

Answer 64

3 exonuclease

Question 65

it constitutes the second level of organization of DNA

Answer 65

nucleosome

Question 66

TRUE of okazaki fragments

Answer 66

fragments of DNA that are copied in direction away from replication fork

Question 67

the post-transcriptional processing prevents 5 exonuclease attack

Answer 67

poly A tail

Question 68

What reaction does the RNA-directed DNA polymerase catalyze?

Answer 68

synthesis of DNA complimentary to the RNA strand

Question 69

During protein synthesis, which reads information in mRNA and transfers AA to a growing polypeptide chain?

Answer 69

transfer RNA

Question 70

What is the cause of polyuria in diabetes mellitus?

Answer 70

osmotic diuresis