DNA, Protein Synthesis, and Gene Terms

Question 1

enzymes that untwist the double helix at the replication forks

Answer 1

helicases

Question 2

goes ahead of replication forks, cuts, unwinds, and rejoins DNA strands

Answer 2

topoisomerase

Question 3

holds the DNA strand straight so it can be used as a template

Answer 3

single-strand binding protein

Question 4

a short strand of RNA that is laid down at the origin of replication

Answer 4

primer

Question 5

enzyme that lays down the primer

Answer 5

primase

Question 6

adds DNA nucleotides to the 3’ end of the primer

Answer 6

DNA Polymerase III

Question 7

a series of primers and new DNA segments

Answer 7

Okazaki fragments

Question 8

removes the RNA primers and replaces them with DNA nucleotides

Answer 8

DNA polymerase I

Question 9

connects the new DNA nucleotides

Answer 9

DNA ligase

Question 10

cutting out damaged DNA and replacing it with new DNA

Answer 10

nucleotide excision repair

Question 11

an enzyme that cuts out damaged DNA

Answer 11

nuclease

Question 12

repetitive nucleotide sequences at the end of DNA that do not contain genes

Answer 12

telomeres

Question 13

an enzyme that lengthens telomeres in gamete DNA

Answer 13

telomerase

Question 14

DNA wrapped around bead like proteins

Answer 14

histones

Question 15

DNA and histones together

Answer 15

chromatin

Question 16

RNA’s base pairs read in sets of 3

Answer 16

codons

Question 17

the beginning of the DNA sequence to be copied

Answer 17

promoter

Question 18

enzyme that attaches to the promoter

Answer 18

RNA polymerase II

Question 19

the promoter begins with a sequence of DNA that includes the base pairs T and A

Answer 19

TATA Box

Question 20

proteins that allow the RNA Polymerase II to bind to the promoter.

Answer 20

transcription factors

Question 21

the promoter, RNA Polymerase II, and Transcription factors all combined and ready to start transcription

Answer 21

transcription initiation complex

Question 22

an enzyme that unwinds DNA and lays down RNA nucleotides

Answer 22

RNA Polymerase

Question 23

causes the mRNA to be cut free from the DNA

Answer 23

termination code

Question 24

a modified guanine nucleotide with 3 phosphate groups

Answer 24

5’ cap

Question 25

several adenine nucleotides in a row (50+)

Answer 25

poly-A tail

Question 26

sections that are cut out of the pre-mRNA

Answer 26

introns

Question 27

sections that are left in the finalized mRNA

Answer 27

exons

Question 28

carry out RNA splicing

Answer 28

spliceosomes

Question 29

make up splicesomes and recognize the splice sites

Answer 29

ribonucleoproteins (snRNPs)

Question 30

catalytic RNA molecules that function as enzymes and can splice RNA

Answer 30

ribozymes

Question 31

choosing different regions of introns or exons from the same pre-mRNA sequence

Answer 31

alternative RNA splicing

Question 32

the enzyme that enzyme that attaches amino acids to tRNA

Answer 32

aminoacyl-tRNA synthetase

Question 33

holds the tRNA that carries the next amino acid to be added to the chain

Answer 33

A-Site

Question 34

holds the tRNA that carries the growing polypeptide chain

Answer 34

P-Site

Question 35

the exit site, where discharged tRNAs leave the ribosome

Answer 35

E-Site

Question 36

several ribosomes translate a single mRNA simultaneously, allowing a cell to make many copies of a protein very quickly

Answer 36

polyribosome (or polysome)

Question 37

a short peptide added to the finished protein

Answer 37

signal peptide

Question 38

attaches to the signal peptide that that it may enter the ER

Answer 38

signal-recognition particle (SRP)

Question 39

a single base pair is affected

Answer 39

point mutation

Question 40

extra base pair

Answer 40

insertion

Question 41

base pair is removed

Answer 41

deletion

Question 42

part of the DNA is duplicated

Answer 42

duplication

Question 43

part of the DNA is reversed

Answer 43

inversion

Question 44

part of the DNA is moved to a different spot

Answer 44

translocations

Question 45

the wrong amino acid is added

Answer 45

missense

Question 46

a stop codon is produced early causing the amino acid chain to end early

Answer 46

nonsense

Question 47

the wrong codon is produced but the correct amino acid is sill added (thus no change)

Answer 47

silent mutation

Question 48

more than one codon can code for the same amino acid. (makes silent mutations possible)

Answer 48

wobble

Question 49

a control site within the promoter that can be blocked to stop transcription (turns the gene off)

Answer 49

operator

Question 50

a protein that slides into the operator to block transcription (the RNA polymerase cannot attach and pass)

Answer 50

repressor

Question 51

promoter + operator + genes they control

Answer 51

operon

Question 52

a molecule that combines with the repressor to change the repressor into its active form. (thus turning the gene off)

Answer 52

co-repressor

Question 53

gene is off until turned on

Answer 53

negative regulation

Question 54

molecule that bonds with the repressor to make it inactive (turns the gene on)

Answer 54

inducer

Question 55

even though the repressor is inactive and the gene is on, protein production must be stimulated

Answer 55

positive regulation

Question 56

stimulates the production of a protein in a gene that is on (calls for RNA polymerase to attach)

Answer 56

activator

Question 57

sites that call for specific activators to stimulate the production of certain proteins

Answer 57

enhancers

Question 58

acetyl groups are added to histone tails

Answer 58

Histone Acetylation

Question 59

a methyl group is added toa base

Answer 59

DNA methylation

Question 60

degrade old protein

Answer 60

Proteasomes

Question 61

molecules added to proteins needed to be broken down

Answer 61

ubiquitin

Question 62

Double stranded degrades or blocks translation of mRNA

Answer 62

siRNA

Question 63

Single stranded but functions similarly to siRNA (may help fight viruses)

Answer 63

miRNA

Question 64

Technique used to get a visual of DNA

Answer 64

X-ray crystallography