Replication and Transcription

Question 1

Protein machine that performs replication is called a

Answer 1

Replisome

Question 2

Replisomes begin at _____

Answer 2

Origins

Question 3

Replication forks

Answer 3

Sites of new DNA syntehsis

Question 4

DNA polymerase vs. RNA polymerase

Answer 4

DNA polymerase has to have a short RNA to start…DNA cannot start polymer

Question 5

What is proofreading activity of DNA polymerase

Answer 5

3’ to 5’ exonuclease activity

Question 6

Why do drugs like AZT work?

Answer 6

Viral reverse transcriptases lack proofreading ability…once substituted, it kills the virus

Question 7

Leading vs. lagging strand

Answer 7

Leading continuous

Lagging - okazaki and discontinuous

Question 8

WHat makes short RNA primer?

Answer 8

RNA primase…on boht leading and lagging strand

Question 9

Replication promotes ____ in front and ______ behind

Answer 9

Positive supercoiling in front (overwound)

Negative supercoiling behind (unwound )

Question 10

Helicase

Answer 10

Unzips double helix

Question 11

Topoisomerases

Answer 11

Relieve supercoil tension

Question 12

Type 1 topoisomerases

Answer 12

Cut one of the strands and allow it to make a turn…then re-lligate

Question 13

Type 2 topoisomerase

Answer 13

Cut both stands and pass another stand through…then re-ligate the two cut strands

Question 14

Etoposide

Answer 14

Interferes with Topo 2 function…this inhibits replication during rapidly dividing cells

Locks the enzyme onto the DNA…triggers apoptosis

Question 15

5-FU

Answer 15

5-flurouracil
Converted to FdUMP which inhibits thymidylate synthase…results in lower levels of dTMP (made to use dTTP) and less replication

Question 16

Thymidylate synthase reaction

Answer 16

dUMP to dTMP (leads to dTTP which leads to replication)

Question 17

Werner Syndrome

Answer 17

Mutation in replication helicases

Rapid-aging disease

Question 18

Errors in replication that lead to nucleotide repeats that lead to repeat number increasing

Answer 18

Nucleotide expansion diseases

Question 19

When and why do nucleotide expansions occur?

Answer 19

When trinucleotide repeats form hairpins…due to self-complpimentary nature

Question 20

Nucleotide expansion occurs if

Answer 20

Hairpin forms on new DNA strand…DNA polymerase is “snapped back”

Question 21

Nucleotide deletion occurs if

Answer 21

Hairpin forms on template DNA strand…DNA polymerase jumps over gap

Question 22

If expansion or deletion is not detected,

Answer 22

It will be replicated and become permanent…this means even a higher chance that more will occur

Question 23

Spinocerebellar ataxia

Answer 23

Nucleotide expansion disease

CAG expansion

Question 24

Anticipation

Answer 24

Children of people with nucleotide expansion syndromes often show symptoms at an earlier age

Question 25

Child nucleotide repeat length vs. parents

Answer 25

Longer

Question 26

RNA has same sequence as ____ and completementary to _____

Answer 26

Top strand | Bottom strand

Question 27

Transcription is regulated by

Answer 27

Proteins that bind to gene promoters and regulate whether RNA polymerase can bind

Question 28

Activators

Answer 28

Help RNA polymerase bind

Question 29

Repressors

Answer 29

inhibit RNA polymerase from binding

Question 30

Proteins that bind promoters recognize

Answer 30

Things like TATA CAAT and GC boxes

Question 31

In eukaryotes, RNA polymerase cannot bind unitil

Answer 31

TF2D binds first

Question 32

TF2D has ____ subunit

Answer 32

TATA Binding protein

Question 33

What has to happen to RNA polymerase before it can transcribe?

Answer 33

Kinase must phosphorylate

Question 34

TNF-alpha stimulates cytokines gene expression via

Answer 34

NF-kB

Question 35

Steroid is a

Answer 35

Ligand that allows receptor to bind and turn on transcription of genes important for specialized function of cells

Question 36

Steps of steroid hormones

Answer 36

``` Binding of steroid hormone to receptr Translocation of complex to nucleus Binding of complex to DNA regulatory site Transcription Translation ```

Question 37

Diseases from promoter sequences

Answer 37

Thalassemias GPI deficiency Alzheimer's APP

Question 38

Promoter mutations can cause disease by

Answer 38

Increasing or decreasing transcription of a gene

Question 39

HNF1-beta

Answer 39

Hepatocyte Nuclear factor 1-beta Important for liver, kidney, pancreas Mutations cause diabetes, liver, and renal disease

Question 40

MODY

Answer 40

Maturity onset diabetes of youth | Mutations of transcriptions factor

Question 41

Transcription facotr diseases

Answer 41

MODY | Diseases of Hepatocyte Nuclear factor 1-beta

Question 42

Androgen receptor

Answer 42

Stimulated by DHT to drive male develpoment and secondary sex characteristics

Question 43

Androgen insensitivity syndrome

Answer 43

``` Female external Blind ending vagina Tests (undescended) Higher testosterone than average F Heterosexual female ID Most present when menstruation does not begin ```

Question 44

Mildest form of AIS

Answer 44

Male genitals, infertility

Question 45

COmplete AIS

Answer 45

Female genitals with little/no pubic underarm hair

Question 46

People with complete AIS are

Answer 46

Infertile and lack fallopian tubes/uterus

Question 47

Amanita Phalloides

Answer 47

Flu-like symtoms Contains alpha-amanitin Inhibits RNA polymerase 2