Replication, transcription, and translations

Question 1

DNA polymerase III

Answer 1

Adds nucleotides to solo DNA strands in 5’ to 3’ direction

Question 2

Primer

Answer 2

short strand of RNA complementary to DNA template strand, required for DNA polymerases to build strand

Question 3

Helicase

Answer 3

Opens DNA helix by breaking hydrogen bonds between nitrogenous bases

Question 4

Leading strand

Answer 4

Passes through replication complex in the correct orientation for addition of new nucleotides

Question 5

Lagging strand

Answer 5

Reverse orientation, requires okasaki fragments

Question 6

Primase

Answer 6

Synthesizes RNA primers needed to start replication

Question 7

Replication fork

Answer 7

Partial opening of DNA helix to form 2 single strands, all enzymatic activites found here

Question 8

Telomere

Answer 8

Specialized structures on ends of eukaryotic chromosomes, protect end of chromosomes from nucleases and maintain integrity of linear chromosomes

Question 9

Telomerase

Answer 9

contains small internal piece of RNA, used as template to extend end of linear DNA molecule

Question 10

Okazaki fragments

Answer 10

Small, discontinuous pieces necessary for growth of lagging strand. Each requires DNA primer strand formed by RNA primase.

DNA polymerase synthesizes complementary DNA starting from 3’ end and working toward previous Okazaki fragment

Question 11

DNA Ligase

Answer 11

Seals gaps between okazaki fragments to create 1 continuous strand of DNA

Question 12

DNA polymerase I

Answer 12

Removes RNA primer and replaces it with newly synthesized DNA

Question 13

Specific repair

Answer 13

Targets single kind of DNA damage

Question 14

Nonspecific repair

Answer 14

Can repair multiple kinds of DNA damage

Question 15

Mismatch repair

Answer 15

removes incorrect bases

Question 16

Photorepair

Answer 16

Recognizes and reverses damage caused by photochemical reactions

Question 17

Excision repair

Answer 17

Nonspecific, damaged region is removed and replaced by DNA synthesis. 3 steps.
1. Recognition of damage
2. Removal of damaged region
3. Resynthesis using info on undamaged strand

Question 18

mRNA

Answer 18

copy of a short section of DNA that can leave the nucleus, carrying along instructions for how to build a protein

Question 19

introns

Answer 19

noncoding DNA that interrupts sequence of gene

Question 20

exons

Answer 20

coding sequences, expressed

Question 21

Codons

Answer 21

3-base segments in mRNA

Question 22

start codon

Answer 22

AUG

Question 23

stop codons

Answer 23

UAA, UAG, UGA

Question 24

Transcription bubble

Answer 24

region containing RNA polymerase, DNA template, and growing RNA transcript

Question 25

Start site

Answer 25

first nucleotide that starts transcribing into mRNA

Question 26

enhancer

Answer 26

regulatory DNA sequences that enchance the transcription of associated gene

Question 27

transcription factors

Answer 27

proteins that boost or limit a gene's transcription

Question 28

tRNA

Answer 28

specialized to carry and install a specific kind of amino acid. Have anticodons (complementary to codons)

Question 29

Central Dogma

Answer 29

Genetic information flows from DNA to RNA to protein