Unit 6 - DNA Replication, Transciption, Translation

Question 1

Topoisomerase

Answer 1

Uncoils the DNA

Question 2

DNA Helicase

Answer 2

Breaks the H-bonds

Question 3

DNA Polymerase III

Answer 3

adds nucleoside triphosphates

Question 4

DNA Polymerase I

Answer 4

replaces RNA primers with DNA

Question 5

Ligase

Answer 5

cleanse up and joins the okazaki fragments

Question 6

Exonuclease

Answer 6

proofreader

Question 7

Endonuclease

Answer 7

cleaves the bad parts

Question 8

Transcription in Eukaryotes

Answer 8

Initiation: promoter region (TATA box); transcription factors help RNA polymerase bind

Elongation occurs

Termination: Polyadenylation Signal Sequence (AAUAAA) releases the pre-mRNA; post-transcription modifications (5’cap, poly-A tail, splicing [splicisomes; alternative splicing increases variation])

Question 9

Transcription in Prokaryotes

Answer 9

Initiation: RNA polymerase directly binds to the promoter region

Elongation: translation happens simultaneously

Termination: termination sequence; no modifications

Question 10

Termination in Eukaryotes

Answer 10

Initiation: universal start codon AUG

Elongation: tRNA brings specific animo acids based off the codons that match with the anticodon on the tRNA; peptide bonds form to make a polypeptide chain; translocation moving from right to left (EPA)

Termination: stop codon at A site

Question 11

Acetylation

Answer 11

loosens/opens up the DNA; increases transcription; on HISTONES

Question 12

Methylation

Answer 12

closes/condenses DNA; reduces/stops transcription; on nucleotide/DNA

Question 13

Epigenetics

Answer 13

external to DNA that will regulate gene expression (heritable)

Question 14

Retrovirus

Answer 14

transcription/translation from RNA to DNA

Question 15

DNA point mutations/substitution mutations

Answer 15

Silent: no impact
Missense: depends on the R-group and if the function is still the same there will be no impact
Nonsense: nonfunctional protein is made

Question 16

Frameshift

Answer 16

nucleotide base is added/deleted which will case all RNA after to shift

could code for accidental stop codon

after the shift point all codons could be different

Question 17

Eukaryotic Enhancers

Answer 17

Enhancers on a DNA sequence will activate transcription factors after folding over due to a bending protein; transcription factors can be activators or repressors

Help regulate gene expression

ex: Cytoplasmic Determinants and Induction

Question 18

HOX Genes

Answer 18

different sports for different genes

different body parts/characteristics will show depending on where it’s turned on

Question 19

TRP Operon (tryptophan)

Answer 19

repressive–normally ON; a substance causes it to be stopped

build up of tryptophan (in this case is also a corepressor which is an enzyme that is produced that also turns it off) will bind to the operator as a repressor (operator inhibits the operon) and the gene will not be produced

when tryptophan is removed, the operon will be able to function again

Question 20

LAC Operon (Lactose)

Answer 20

inducible–normally OFF; a substance causes it to start

takes advantage of lactose when it shows up for ATP

when there is lactose in the environment, an inducer will attach to the operator and the repressor is released which will allow the rest of it to make genes that break down the lactose and use it

Question 21

Lytic Cycle – bacteriophage

Answer 21

1. insert virus DNA into bacteria
2. break host DNA
3. reproduce
4. cell lysis
5. infect other bacteria

Question 22

Lysogenic

Answer 22

viral DNA – replicated with binary fission

Question 23

Transformation

Answer 23

• bacteria dies and the DNA is released into the environment
• other bacteria uptake the naked DNA to change the geno/phenotype

Question 24

Transduction

Answer 24

cell to new, bacteria to bacteria

cell breaks and sends new DNA (virus) out

can also be bacteria DNA

Question 25

Conjugation

Answer 25

temporary bridge; passing plasmid

Question 26

Transposon

Answer 26

section of DNA (transposon) can be put into different section

Question 27

Restriction enzyme

Answer 27

recognize specific sequences on DNA (restriction sites)

Question 28

DNA Cloning

Answer 28

1. cuts parts – corresponding/complementary sticky ends
2. ligase binds phosphodiester linkage
3. bacteria takes up and transforms (makes more)
   - scientists add antibody resistance on plasmid; all that’s left will be resistant plasmids (success)

Question 29

Gel Electrophoresis

Answer 29

cute DNA with restrictors
DNA = negative charge (will separate)
DNA Ladder: # of bases

top - large - negative
bottom - small - positive

Question 30

Polymerase chain reaction

Answer 30

1. denaturation: add head to the separate strands
2. annealing: cool down, add primers
3. DNA synthesis (warmer) start

for electrophoresis and diagnostics