DNA Replication

Question 1

5’ end has a _______

Answer 1

Phosphate group

Question 2

3’ end has a

Answer 2

OH group

Question 3

DNA replicates via __________

Answer 3

conservative replication

Question 4

conservative replication

Answer 4

The parental molecule serves as a template for the synthesis of an entirely new molecule

Question 5

DNA Polymerase

Answer 5

Catalyzes DNA synthesis

Question 6

DNA Polymerase adds deoxyribonucleotides to the _________

Answer 6

• 3’ end
• DNA synthesis proceeds 5’ to 3’

Question 7

How many origins do bacterial chromosomes have?

Eukaryotic?

Answer 7

1, multiple

Question 8

Helicase

Answer 8

Catalyzes breaking of h-bonds between the two DNA strands to separate

Question 9

Single-strand DNA-binding proteins (SSBPs)

Answer 9

attach to separated strands to prevent them from closing

Question 10

Topoisomerase

Answer 10

• cuts and rejoins DNA
  
  • downstream of the replication fork
  • relieving tension in the helix

Question 11

Primer

Answer 11

• A few nucleotides bonded to the template strand
• Provides a free 3’ hydroxyl group that can combine w/ incoming dNTP to form a phosphodiester bond

Question 12

Primase

Answer 12

• Type of RNA polymerase​
• synthesizes RNA primer
• DNA polymerase III adds bases to 3’ end of primer

Question 13

Leading strand

Answer 13

• Product of DNA polymerase 3
• Leads into replication fork
• synthesized 5’ to 3’

Question 14

Sliding clamp

Answer 14

holds DNA polymerase in place

Question 15

Laggin strand

Answer 15

• Synthesized discontinuously
• away from replication fork
• 5’ to 3’ direction

Question 16

Okazaki fragment

Answer 16

short, newly synthesized DNA fragments complimentary to lagging template strand

Question 17

DNA polymerase I

Answer 17

Removes RNA primer and replaces with DNA

Question 18

DNA ligase

Answer 18

joins okazaki fragments into a continuous strand

Question 19

DNA polymerase III

Answer 19

Extends leading strand or okazaki fragment

Question 20

Telomere

Answer 20

• Region at end of linear chromosome
• does not contain genes
• short, repeating stretches of bases

Question 21

Problems of telomeres

Answer 21

• Leading-strand synthesis normal copy of DNA
• Telomere on lagging strand shortens during DNA replication

Question 22

Telomerase

Answer 22

extends telomere from 3’ to 5’ of lagging strand

Question 23

Somatic cells _______ telomerase

Answer 23

• chromosomes of somatic cells progressively shorten as individual ages

Question 24

Repair enzymes

Answer 24

remove defective bases and repair them

Question 25

Mismatch repair

Answer 25

occurs when mismatched bases are corrected after DNA synthesis is complete

Question 26

UV light can cause ______ to form

Answer 26

* thymine dimers * produce kink in DNA strand

Question 27

Important properties of genetic code

Answer 27

* Redundant * Unambiguous * non-overlapping * conservative

Question 28

Redundant

Answer 28

all aa coded by more than one condon

Question 29

Unambiguous

Answer 29

Single codon never codes for more than one amino acid

Question 30

non-overlapping

Answer 30

reads each separate codon one after another

Question 31

conservative

Answer 31

first two bases always identical-less likely to change if mutation in 3rd position

Question 32

Transcription

Answer 32

H-bonds form between complimentary base pairs of template strand

Question 33

RNA is made from the ________ strand

Answer 33

template

Question 34

Coding strand

Answer 34

Same nucleotide sequence as RNA being made

Question 35

Template strand

Answer 35

Complimentary strand of coding strand

Question 36

Template strand and RNA should \_\_\_\_\_\_

Answer 36

Match except RNA has U instead of T

Question 37

RNA polymerase

Answer 37

links nucleotides together to make RNA

Question 38

Promoter region

Answer 38

Where RNA polymerase binds w/ helper protein

Question 39

Helper proteins:

Answer 39

* Prokaryotes * sigma * Eukaryotes * transcription factors

Question 40

coding region

Answer 40

* Region that codes for an amino acid * Exon

Question 41

Noncoding region

Answer 41

* nonsense region that doesn't code for amino acid * intron

Question 42

5' cap

Answer 42

recognition signal for translation machinery

Question 43

Poly(A) tail

Answer 43

extends life of an mRNA by protecting it from degradation

Question 44

Elongation during translation

Answer 44

* tRNA with correct anticodon enters A site w/ correct amino acid * moves to P site and peptide bond is made between amino acid and next amino acid * tRNA then moves to E site and leaves * Repeat until stop codon

Question 45

Terminating translation

Answer 45

* Release factor binds to stop codon * polypeptide/tRNAs fall off * ribosome subunits separate

Question 46

Transcription/translation overview

Answer 46

* Transcription * DNA to RNA * Translation * RNA to proteins

Question 47

sickle cell anemia

Answer 47

* point mutation * changes structure of protein so affects phenotype/function

Question 48

Silent mutation

Answer 48

Change in nucleotide sequence that does not change AA

Question 49

Missense

Answer 49

Change in nucleotide sequence that changes amino acid specified by codon

Question 50

nonsense

Answer 50

change in nucleotide sequence that results in early stop codon

Question 51

Frameshift

Answer 51

Addition or deletion of a nucleotide

Question 52

Beneficial mutation

Answer 52

increase organism's ability to survive and reproduce

Question 53

neutral

Answer 53

no effect

Question 54

deleterious

Answer 54

lower organism's ability to survive and reproduce