Exam 3

Question 1

Parts of nucelosides

Answer 1

base and sugar

Question 2

parts of nucleotides

Answer 2

base, sugar, phosphate

Question 3

bases

Answer 3

A, C, G, T

Question 4

Purines are ___ and ___

Answer 4

A and G

Question 5

Purines have ____ rings and are ____ (size)

Answer 5

two rings, larger

Question 6

Pyrimidines are _, _, and _

Answer 6

C, U, and T

Question 7

Pyrimidines have ___ ring(s) structure and are ____ in size

Answer 7

one; smaller

Question 8

Who discovered a X-ray diffraction pattern from a DNA smear but were unable to identify the structure

Answer 8

Franklin and Wilkins

Question 9

What was significant about Watson and Crick’s model

Answer 9

postulated a double stranded molecule with an anti-parallel orientation of strands, bases inside

Question 10

____ pairs to ____ using 3 H bonds

Answer 10

C pairs to G

Question 11

__ pairs to __ using 2 H bonds

Answer 11

A pairs to T

Question 12

how many bases per twist; length of each twist

Answer 12

10 base pairs; 3.4 nm per twist

Question 13

what does Chargaff’s rule state

Answer 13

purines match with pyrimidines by forming hydrogen bonds

Question 14

Both DNA strands have the same amount of information, why?

Answer 14

The bases in 1 strand are complementary to those in the other strand

Question 15

Modern Central Dogma

Answer 15

Replication-transcription-translation-modification

Question 16

DNA strucure, what at 5’ and 3’

Question 17

Meselson and Stahl

Answer 17

Different suggestions on possible mode of DNA replication

Question 18

Conservative DNA

Answer 18

heavy and light DNA,

Question 19

Semiconservative DNA

Answer 19

used in DNA replication

Question 20

Dispersive DNA

Answer 20

stripe pattern of of heavy and light DNA

Question 21

Genome

Answer 21

complete cell DNA sequence

Question 22

genotype

Answer 22

specific DNA sequence

Question 23

phenotype

Answer 23

Appearance and/or behavior

Question 24

What are considered large molecules

Answer 24

free-living cells ranging from 583,000 up to 15 billion nucleotides

Question 25

Shape and ploidy of most prokaryotes

Answer 25

circular and haploid

Question 26

Nucleoid of E. coli is has multiple loops held by anchoring proteins. Each loop contains _____

Answer 26

supercoiled DNA

Question 27

positive supercoiling vs negative supercoils

Answer 27

positive: over winding DNA negative: under winding DNA

Question 28

Helicase

Answer 28

Placed at each end of origin by loader and moves in each direction to copy genome by "melting DNA" "unwinding enzyme"

Question 29

What enzyme requires free 3' OH

Answer 29

DNA polyermase

Question 30

Primase

Answer 30

Begins replication by making a free 3'OH for DNA polymerase

Question 31

Who is associated with Nuclein in 1869

Answer 31

Miescher

Question 32

Transformation in 1928

Answer 32

Griffith

Question 33

Transformation 1944

Answer 33

Avery, MacLeod, McCarty

Question 34

Blender experiment 1944

Answer 34

Hershey and Chase

Question 35

The "rules" in 1948

Answer 35

Chargaff

Question 36

What relieves torsional stress causes by supercoils?

Answer 36

Type I Topoisomerases

Question 37

What introduces negative supercoils

Answer 37

Type II Topoisomerases

Question 38

What introduces positive supercoils

Answer 38

Archaeal topoisomerases

Question 39

``` semi-conservative replication: 1: 2: 3: 4: 5: ```

Answer 39

1: Copies information to complementary strand 2: melt double-stranded DNA 3: polymerize new strand 4: DNA opened at oriC 5: polymerization follows bi-directionally around chromosome

Question 40

What is the order of events for DNA replication?

Answer 40

1: DNA Helicase unwinds the DNA 2: Primase makes a free 3'OH avaialbe 3: DNA polymerase uses free 3'OH and clamp binds DNA polymerase III to strand 4: Polymerase proceeds 5' to 3' on each strand with energy for polymerization coming from phosphate groups on the recently added nucleotide 5: Gaps filled in by DNA polymerase I Ligase seals nicks

Question 41

Replisomes are _____, so DNA is threaded through the replisomes

Answer 41

stationary

Question 42

Extrachromosomal pieces of DNA

Answer 42

Plasmids

Question 43

What are the two types of plasmids and how many copies of plasmids are there per cell for each

Answer 43

Low-copy-number: one or two copies per cell | High-copy-number: up to 500 copies per cell that divide continuously and randomly segregate

Question 44

Plasmid replication is similar to chromosomal replication since they both are _______ replication

Answer 44

Bidirectional

Question 45

Plasmid replication can occur _____, like chromosomal replication or _____

Answer 45

Bidirectionally; unidirectional