290-299

Question 1

nucleotides

Answer 1

Protein synthesis

■ Nucleic acid synthesis

■ Signal transduction pathways

Question 2

nuceltides

Answer 2

Composed of three basic compounds:

■ Nitrogenous base

■ Purine

■ Pyrimidine

■ Pentose sugar

■ Deoxyribose

■ Ribose

■ Phosphate group(s)

Question 3

Purines

Answer 3

pair with pyrimidines

Question 4

Adenine—Thymine/Uracil (—-H-bonds).

■ Guanine—Cytosine (—- H-bonds).

Answer 4

Adenine—Thymine/Uracil (two H-bonds).

■ Guanine—Cytosine (three H-bonds).

Question 5

https://drive.google.com/open?id=0B8uJUY-tie8Gd25jNzZFNV93cW8

Answer 5

https://drive.google.com/open?id=0B8uJUY-tie8Gd0NtMG04OFZRZFk

Question 6

purines

Answer 6

catabolize to Uric acid

Question 7

antifolate and

anticancer drugs

Answer 7

purine

metabolic defects

Question 8

Gout

Hyperuricemia

G-6-P deficiency

Answer 8

cat defect of purine

Question 9

uracil and cytotoxine

Answer 9

rna bases of pyrimidine

Question 10

thymine and cytosine

Answer 10

dna base of pyrimidine

Question 11

UV light

Methotrexate

Other anticancer

drugs

Answer 11

metabolic defects of pyr

Question 12

Rare (highly water soluble

Answer 12

pyr cat defect

Question 13

β-Alanine

β-Amino-

Answer 13

pyr cat. to

Question 14

https://drive.google.com/open?id=0B8uJUY-tie8GWnp1Zy1QQmtRbTA

Answer 14

https://drive.google.com/open?id=0B8uJUY-tie8GWnp1Zy1QQmtRbTA

Question 15

NA

Answer 15

Extremely polar and hydrophilic.

■ The “backbone” consists of pentose sugars linked by phosphodiester

bonds at the third and fifth carbon atoms.

Question 16

Nuc. acid

Answer 16

The two polynucleotide chains are considered antiparallel and complementary

(one chain runs in the 5′ → 3′ direction; the other runs in the

3′ → 5′ direction).

Question 17

https://drive.google.com/open?id=0B8uJUY-tie8GQlowWmVpYTRacEE

Answer 17

https://drive.google.com/open?id=0B8uJUY-tie8GMXE2REgxOWhXWTA

Question 18

Nucleolus

Answer 18

site of syn of rrna

Question 19

Most prevalent rna

Answer 19

rrna

Question 20

nucelus

Answer 20

trna mrna

Question 21

Carries amino acids
from cytosol

Contains an anticodon

(complementary

to ribosomes to mRNA codons)

Answer 21

trna

Question 22

mrna

Answer 22

Carries genetic code

from DNA Contains codons to ribosomes

Question 23

Least prevalent RNA.

Contains codons

(complementary

to DNA template

and tRNA anticodon)

Answer 23

mrna

Question 24

deoxyribose sugars linked together via

Answer 24

phosphodiester bonds.

Question 25

The backbone structure of a single RNA strand. It is constant:

Answer 25

ribose sugars linked together via phosphodiester bonds

Question 26

nucleosome

Answer 26

Consists of DNA wrapped around a histone octomer. ■ Held by ionic bonds

Question 27

https://drive.google.com/open?id=0B8uJUY-tie8GUEV6SXRjMDk3Q3c

Answer 27

https://drive.google.com/open?id=0B8uJUY-tie8GX2dMMWJQampCd1E

Question 28

chromatin

Answer 28

Consists of nucleosomes, enzymes, gene regulatory proteins (transcription factors), and small amounts of RNA.

Question 29

Unwinds the DNA molecule

Answer 29

helicase

Question 30

. Secures the replication fork, where the two DNA strands are separated into leading and lagging strands

Answer 30

■ Topoisomerase:

Question 31

Forms new complementary strands in the 5′ → 3′ direction.

Answer 31

DNA polymerase:

Question 32

Runs in the 3′ → 5′ direction. Synthesized continuously

Answer 32

Leading strand:

Question 33

Runs in the 5′ → 3′ direction. Synthesized in segments (Okazaki fragments).

Answer 33

Lagging strand:

Question 34

Joins Okazaki fragments

Answer 34

DNA ligase:

Question 35

Removes the nuclueotide primer

Answer 35

Exonuclease:

Question 36

Reforms the supercoiled structure once the replication fork has passed.

Answer 36

DNA gyrase:

Question 37

DNA is used as a template to form RNA. ■ Occurs in the nucleus.

Answer 37

Rna syntesis

Question 38

DNA is unwound and the replication fork is exposed. ■ RNA polymerase binds to a promoter site on the DNA strand.

Answer 38

rna synthesis

Question 39

rna synthesis

Answer 39

Synthesis occurs in the 5′ → 3′ direction. ■

Question 40

Addition of a 5′ cap and a 3′ poly(A) tail. ■ RNA splicing: ■ Removal of introns (noncoding segments). ■ Subsequent joining of exons (coding segments).

Answer 40

rna synthesis

Question 41

An mRNA template is used to determine the specific amino acid sequence for polypeptide synthesis

Answer 41

protein synthesis

Question 42

Occurs in the cytoplasm (in ribosomes). ■ A small ribosomal subunit binds to mRNA.

Answer 42

protein synthesi

Question 43

https://drive.google.com/open?id=0B8uJUY-tie8GNXFJaGl5TE5ZZFU

Answer 43

https://drive.google.com/open?id=0B8uJUY-tie8GSDI5MFdHUUcwOW8

Question 44

Aminoacyl-tRNA synthetase■

Answer 44

: Adds each amino acid to tRNA.

Question 45

The complementary anticodon of tRNA (carrying the first amino acid)

Answer 45

binds to the mRNA start codon

Question 46

A ---- ribosomal subunit attaches, forming a complete ribosome.

Answer 46

A large ribosomal subunit attaches, forming a complete ribosome.

Question 47

Synthesis occurs in the 5′ → 3′ direction

Answer 47

until a stop codon is reached

Question 48

https://drive.google.com/open?id=0B8uJUY-tie8GSk0takN3RllVX0U

Answer 48

https://drive.google.com/open?id=0B8uJUY-tie8GQ1VDSWhmUFBtWkk

Question 49

Caused by mutagenic chemicals, radiation, UV light, and some viruses. ■ Due to failure of DNA repair mechanisms.

Answer 49

mutation

Question 50

■ Missense mutation:

Answer 50

Results in a codon that causes an altered amino acid sequence (eg, valine replaces glutamate causing sickle cell anemia).

Question 51

Nonsense mutation:

Answer 51

Results in a stop codon that causes polypeptide chain termination.

Question 52

Transverse mutation:

Answer 52

A purine is replaced with a pyrimidine, or vice versa (the purine–pyrimidine orientation is changed).

Question 53

Transition mutation:

Answer 53

A purine is replaced with another purine, or a pyrimidine is replaced with another pyrimidine (the purine–pyrimidine orientation is not changed).

Question 54

Deletion or insertion of one or two base pairs, changing the reading frame of the DNA template and the amino acid sequence.

Answer 54

frameshift mut.

Question 55

Amplification of the sequence of three nucleotides.

Answer 55

repeated mut.

Question 56

Forms a complementary strand of DNA from the original RNA. ■ HIV contains only a single-stranded RNA molecule and its own reverse transcriptase.

Answer 56

reverse trans.

Question 57

Restriction endonucleases:

Answer 57

Cleave DNA at various points to allow addition of various vectors, plasmids, cosmids, or bacteriophages

Question 58

DNA ligases:

Answer 58

Join DNA fragments.

Question 59

DNA polymerase:

Answer 59

Adds nucleotides.

Question 60

Exonucleases:

Answer 60

Remove nucleotides.

Question 61

Amplifies a target sequence of DNA. ■ Extremely sensitive, selective, and fast.

Answer 61

PCR

Question 62

Used extensively in forensic medicine.

Answer 62

PCR

Question 63

1. Denaturation of the DNA sample into two strands 2. Anneal primers to each strand

Answer 63

PCr

Question 64

3. Copy each strand by a heat-stable DNA polymerase 4. Repeat cycle resulting in exponential amplification of sample

Answer 64

PCR