Biology Test 4

Front 1

DNA

Substance of ?????

Located on ??????

Polymer composed of monomers called ???????

Back 1

inheritance

chromosomes

nucleotides

Front 2

Each nucleotide contains:

Back 2

phosphate group
pentose sugar deoxyribose
nitrogenous bases

Front 3

4 Bases

Back 3

T Thymine
A Adenine
C Cytosine
G Guanine

Front 4

Know in 1950

Heriditary Materials

Back 4

on chromosomes

Front 5

Chromosomes composed of ????? and ?????

Back 5

protein and DNA

Front 6

Most thought ???? contained the genetic material, because

Back 6

proteins, more diverse molecules

Front 7

Alfred Hershey and Martha Chase provided best evident that

Back 7

DNA was genetic material

Front 8

Alfred Hershey and Martha Chase
studied

Back 8

bacteriophage (virus that infects bacteria)

Front 9

Virus

Back 9

DNA surrounded by protein coat

Front 10

T2 infects

Back 10

bacteria E.Coli

Front 11

T2 quickly reprograms E.Coli to

Back 11

produce T2 phages, released when cell lyses

Front 12

Hershey and Chase
Step 1

Seperate dishes, label viral protein w/ ?????? and viral DNA w/ ??????

Back 12

radioactive sulfur and
radioactive phosphorous

Front 13

Hershey and Chase
Step 2

Allow protien and DNA labeled phages to infect ??????

Back 13

E.Coli

Front 14

Hershey and Chase
Step 3

Agitate Cultures which

Back 14

shakes loose phage outside bacteril cells

Front 15

Hershey and Chase
Step 4

????? cultures
heavier bacteria cells in pellet on ????? of test tube

Back 15

centrifuge

bottom

Front 16

Hershey and Chase
Step 5

test ????? of supernatant and pellets, compare results

Back 16

radioactivity

Front 17

Hershey and Chase
Results

when proteins labeled, most radioactivity in ?????

when DNA labeled, most radioactivity in ??????

Back 17

supernatant (outside)

pellet (in E.Coli)

Front 18

Hershey and Chase

When DNA labeled phages return to culture medium, bacteria release ????? w/ labeled ?????

Back 18

progreny, P in DNA

Front 19

Hershey and Chase

Which viral component was responsible for reprogramming the host bacteria cell? Protein or DNA?

Back 19

by devising experiment that showed the only one component (DNA) actually enters E.Coli during infection

Front 20

Hershey and Chase

Conclusions

Virial protein remain ????? of host cell

Viral ???? injected into host cell

Injected DNA causes cells to ??????

DNA is

Back 20

outside

DNA

produce additional viruses

Heriditary material, Nobel Prize 1969

Front 21

Erwin Chargaff

Compared number and ratio of ????? in many Eukaryotes

Back 21

nitrogenous bases

Front 22

Erwin Chargaff

Used ????

Back 22

paper chromatography

Front 23

Erwin Chargaff

DNA composition ?????? from one species to another

amount and ratio of ???????? varies between species

Back 23

varies

nitrogenous bases

Front 24

Chargaff's Rule

A = ?
C = ?

Back 24

A = T
C = G

Front 25

Watson and Crick

Saw ???? of colleague

Back 25

X-ray photograph

Front 26

Watson and Crick

Determined from photo

must be ????

?????? within every full turn

width of helix ????

Back 26

helix

10 nitrogenous bases

2 nanometers

Front 27

Watson and Crick

2 strands of DNA make up ????

always match`

Back 27

Helix

A-T and C-G

Front 28

The Double Helix

5' ?????
3' ?????

Back 28

Phosphate group on #5 carbon

OH group on # 3 Carbon

Front 29

The Double Helix

C-G ?????

A-T ?????

Back 29

3 hydrogen bonds

2 hydrogen bonds

Front 30

5' and 3' end at ?????

Back 30

opposite corners

Front 31

DNA Replication

Template Mechanism ????

Back 31

suggests how it should happen

Front 32

DNA Replication


2 strands ?????

each strand is ????? for creating new strand

???? ????? line up singly along template in accordance with base-pairing rules, nucleotides link together

each new DNA molecule has ???? and ????

Back 32

separate

template

free nucleotides

1 new strand and 1 old strand

Front 33

DNA Replication


3 models

Conservative

Semi-conservative

Dispersive

Back 33

parent molecule intact, new molecules is made entirely of new nucleotides

template model, both old and new DNA molecules have 1 old, 1 new strand of DNA

old and new DNA molecules are mixtures on all strands

Front 34

Matthew Meselson

Step 1

Back 34

label E. coli bacteria with heavy isotope of N (15N), reproduce

Front 35

Matthew Meselson

Step 2

Back 35

transfer culture to light isotope of N (14N)

Front 36

Matthew Meselson

Step 3

Back 36

centrifuge after 1 replication of cells (20 minutes), look at density of bands

Front 37

Matthew Meselson

Step 4

Back 37

centrifuge after 40 minutes (2 replications), look at density of bands

Front 38

replication occurs during ??????? in mitosis and meiosis

Back 38

interphase

Front 39

prokaryotes add 500 nucleotides/sec
eukaryotes add 50/sec

Back 39

Accurate: 1/billion incorrectly paired
Complex

Front 40

Origins of replication:

Back 40

specific sites (nucleotide sequences) where replication begins

Front 41

Double helix opens and creates a ?????

Back 41

bubble

Front 42

Bacteria, viruses:

Back 42

1 origin

Front 43

Eukaryotes:

Back 43

many origins, eventually fuse (speeds things up)

Front 44

Location of split = ?????????, Y-shaped region where DNA is unwound

Back 44

Replication fork

Front 45

To separate strands: ???????
Enzymes that catalyze unwinding of parent double helix

Back 45

Helicases

Front 46

Topoisomerase:

Back 46

Enzyme that corrects overwinding ahead of replication fork

Front 47

Single-strand binding proteins:

Back 47

Proteins that keep separated strands apart

Front 48

Need ????? to start replication process

Back 48

Primer

Front 49

Primer:

Back 49

short RNA segment held together by enzyme Primase

~10 nucleotides long in eukaryotes

Front 50

Elongation

Complimentary bases align along
?????? of old DNA strand

Back 50

template

Front 51

DNA pol III

Back 51

links bases together

Front 52

Daughter strands always grow

Back 52

5’ -> 3’

parent strands antiparallel
continuous synthesis of both
strands not possible

Front 53

Leading Strand

Back 53

5’ -> 3’ daughter strand synthesized continuously into single polymer

Front 54

DNA pol III

Back 54

molecules add complimentary DNA nucleotides

Front 55

Leading Strand requires ?????? , remove RNA with ?????

Back 55

1 RNA primer

DNA pol I

Front 56

Elongation of Lagging Strand

5’ -> 3’ daughter strand synthesized in pieces called

Back 56

Okazaki fragments

Front 57

Elongation of Lagging Strand

DNA pol III molecules add

Back 57

complimentary DNA nucleotides

Front 58

Elongation of Lagging Strand

After 2nd fragment is produced,
remove RNA with ????? and link Okazaki fragments with ??????

Back 58

DNA pol I

DNA Ligase

Lagging Strand requires many RNA primers and thus many DNA pol I and DNA Ligase molecules

Front 59

Okazaki fragments

Synthesized against ???????

Link together with ?????

Length ????

Back 59

overall direction of replication

DNA ligase

Length: 1000-2000 nucleotides in bacteria
Length: 100-200 nucleotides in eukaryotes

Front 60

Helicase

Back 60

Unwinds double helix

Front 61

Single-strand binding protein

Back 61

Stabilizes unwound DNA

Front 62

Topoisomerase

Back 62

Corrects overwinding before replication fork

Front 63

Primase

Back 63

Works with RNA primer to start replication

Front 64

DNA pol III

Back 64

Adds DNA nucleotides to the new strand

Front 65

DNA pol I

Back 65

Removes RNA from RNA primer and replaces with DNA

Front 66

DNA Ligase

Back 66

Links Okazaki fragments and DNA that replaces primers

Front 67

pieces on lagging strand called

Back 67

Okazaki fragments

Front 68

Nucleases

Back 68

correct accidental changes in existing segments of DNA

Front 69

always add new nucleotides at ???? of DAUGHTER STRAND, away from replication fork

Back 69

3'

Front 70

Polymerase only removes/corrects ????

Back 70

daughter strand

Front 71

Transcription:

Complimentary sequences of ??????

Same language of ?????

Back 71

Synthesis of RNA using DNA template

messenger RNA (mRNA)

nucleotides

Front 72

Translation:

Occurs on ?????

4 nucleotides -> ??????

Back 72

Synthesis of polypeptides using mRNA template

ribosomes

20 amino acids

Front 73

coupled

Back 73

Prokaryotes (includes bacteria): No nucleus to physically separate
Transcription and translation

Front 74

Eukaryotes: nucleus separates processes

Back 74

uncoupled

Front 75

3:1 correspondence
total 64 amino acids (43)

Back 75

Will Work

Front 76

Research verified flow of information through ?????

Back 76

triplet code (triplet =codon)

Front 77

Marshall Nirenberg

Back 77

First codon deciphered

Front 78

AUG:

Back 78

start signal for translation, then is replaced with methionine (Met)

Front 79

UAA, UAG, UGA

Back 79

stop codons

Front 80

Redundancy:

Back 80

2 or more codons can code for same amino acid

Front 81

Ambiguity:

Back 81

no! each triplet codes for only one amino acid

Front 82

A G C T

Back 82

DNA NUCLEOTIDES

Front 83

A G C U

Back 83

RNA NUCLEOTIDES

Front 84

Transcription

Goal

Back 84

Synthesis of messenger RNA (mRNA) from single DNA strand

Front 85

Transcription

Start at ???????: specific DNA sequence

Ends at ??????: specific DNA sequence

Back 85

Promoter

Terminator

Front 86

Transcription Unit

Back 86

stretch of DNA that is transcribed

Front 87

RNA polymerase

separates 2 strands of ?????

adds nucleotides ??????

links ??????

Back 87

attaches at promoter

DNA

5’ -> 3’

nucleotides

Front 88

Prokaryotes

Back 88

immediately ready for translation. No alterations.

Front 89

Eukaryotes:

Back 89

mRNA altered before leaving nucleus = RNA processing. 5’ cap added to 5’ end of RNA. Poly-A tail added to 3’ end of RNA. Why? Facilitate export from nucleus, Protect RNA from degrading, Help attach to ribosomes. UTR = untranslated regions at each end of transcribed RNA (also help with ribosome binding).

Front 90

RNA Splicing

Back 90

remove non-coding sequences of RNA (introns) and leave the coding sections (exons) + UTR

Front 91

snRNPS

Back 91

(small nuclear ribonucleoproteins) that are part of the intron and spliceosomes

allows RNA splicing

Front 92

Transcription

In the ????

DNA to ????

Back 92

Nucleus

mRNA