1.2 - INTRODUCTION TO MOLECULAR BIOLOGY

Question 1

Isolated nuclein in WBC nuclei

Answer 1

Friedrich Miescher
1869

Question 2

Performed experiments using several different strains of S. pneumoniae

Answer 2

Frederick Griffith
1928

Question 3

Discovered that DNA transmits killing ability in bacteria

Answer 3

Avery, MacLeod, McCarty
1940s

Question 4

Determined that the part of a virus that infects and replicates is its nucleic acid and not its protein

Answer 4

Hershey and Chase
1950

Question 5

Discovered DNA components, proportions and positions

Answer 5

Levene, Chargaff, Wilkins, Franklin
1909-1950s

Question 6

Elucidated DNA’s three-dimensional structure

Answer 6

Watson and Crick
1953

Question 7

DNA

Double helix

Answer 7

2 strands; right-handed

Question 8

DNA

Direction

Answer 8

5’ →3’ and 3’ →5’

Question 9

DNA

Bases

Answer 9

Perpendicular to the axis

Question 10

DNA

Base bonding

Answer 10

Hydrogen bonds

Question 11

DNA

Turn size

Answer 11

One complete turn 34 Å

Question 12

DNA

Diameter

Answer 12

20 Å

Question 13

DNA

Proportionality of bases

Answer 13

Adenine = Thymine
Guanine = Cytosine

Question 14

DNA

Amount of bases

Answer 14

Purines (A + G) = Pyrimidines (T + C)

Question 15

DNA

Percentage of bases

Answer 15

% A + T ≠ % G + C

Question 16

process by which a molecule of DNA is duplicated

Answer 16

Replication

Question 17

synthesis of RNA from the coding strand of DNA by RNA polymerase

Answer 17

Transcription

Question 18

transfer of genetic information from the sequence of codons in mRNA into a sequence of amino acids in a polypeptide chain

Answer 18

Translation

Question 19

GST supergene family is made up of 4 gene families responsible for the biotransformation of drugs and xenobiotics

Answer 19

GSTA, GSTM, GSTP GSTT

Question 20

subfamilies exhibit homozygous deletions considered as modifiers of individual risk of cancers

Answer 20

GSTT1 and GSTM1

Question 21

is absent in 20% of Caucasians and 60% of Asians

Answer 21

GSTT1

Question 22

is absent in 30-70% of the population

Answer 22

GSTM1

Question 23

is recruited to the origin. Replication bubble allows both strands to be copied in opposite directions

Answer 23

Helicase

Question 24

Helicase recruit primase, which will synthesize ? on both strands.

Answer 24

RNA primers

Question 25

? are recruited. This interacts with the ? to elongate the 3’ end of RNA primers

Answer 25

DNA polymerases sliding clamp

Question 26

Replication forks travel in opposite directions. Helicase works to unwind the DNA, allowing synthesis of new strands to occur. Replication produces short fragments of DNA known as

Answer 26

Okazaki fragments

Question 27

Okazaki fragments are attached together by the

Answer 27

DNA ligase

Question 28

Replication is complete. RNA primers are removed, and ? fill in nucleotides. DNA ligases seal any gaps that remain

Answer 28

DNA polymerases

Question 29

parent strand of DNA which runs in the 3’ to 5’ direction toward the replication fork and is replicated continuously by DNA polymerase

Answer 29

Leading strand

Question 30

parent strand that runs in the 5’ to 3’ direction toward the fork and is replicated discontinuously

Answer 30

Lagging strand

Question 31

1. mRNA binds to small subunit along with initiation factors (IF1, IF2, IF3) 2. Initiator N-formylmethionine (tRNAfmet) binds to mRNA codon in P (peptidyl) site; IF3 released 3. Large subunit binds to complex; IF1 and IF2 released; Elongation factors (EF) binds to tRNA facilitating entry into A (aminoacyl) site

Answer 31

Initiation of translation

Question 32

1. Second charged tRNA enters the A site facilitated by EF 2. Peptide bond forms; uncharged tRNA moves to the E (exit) site and subsequently out of the ribosomes 3. Third charged tRNA enters the A site facilitated by EF 4. Tripeptide is formed. Uncharged tRNA moves to the E site 5. Polypeptide chain is synthesized and exits the ribosome

Answer 32

Elongation of polypeptide

Question 33

1. tRNA and polypeptide chain is released 2. GTP-dependent termination factors are activated; components separate; polypeptide folds into protein

Answer 33

Termination of translation and release of polypeptide

Question 34

Four Levels of Protein Structure

Answer 34

primary secondary tertiary quaternary

Question 35

the sequence of amino acid in a polypeptide chain

Answer 35

Primary

Question 36

the pleated or helical structure in a protein molecule that is brought about by the formation of bonds between amino acids

Answer 36

Secondary

Question 37

the three-dimensional structure of a protein molecule brought about by folding on itself

Answer 37

Tertiary

Question 38

the structure formed by the interaction of two or more polypeptide chains in a protein

Answer 38

Quaternary

Question 39

Actin, myosin, dystrophin

Answer 39

Muscle contraction

Question 40

Antibodies, antigens, cytokines

Answer 40

Immunity

Question 41

Lipase, proteases, nucleases

Answer 41

Digestion

Question 42

Collagen, elastin

Answer 42

Milk protein

Question 43

Colony stimulating factors, erythropoietin

Answer 43

Blood cell formation

Question 44

DNA and RNA polymerase

Answer 44

DNA replication, gene expression

Question 45

Ferritin

Answer 45

Iron transport in blood

Question 46

Fibrin, thrombin

Answer 46

Blood clotting

Question 47

Growth factors, kinases, cyclins

Answer 47

Cell division

Question 48

Hemoglobin, myoglobin

Answer 48

Oxygen transport

Question 49

Insulin, glucagon

Answer 49

Control of blood glucose level

Question 50

Keratin

Answer 50

Hair structure

Question 51

Tubulin, actin

Answer 51

Cell movements

Question 52

Tumor suppressors

Answer 52

Cancer prevention