Unit 6

Question 1

What is central dogma?

Answer 1

DNA –> RNA –> polypeptide

Question 2

Do retroviruses partake in central dogma?

Answer 2

No; they use reverse transcriptase to turn RNA –> DNA

Question 3

Where does DNA replication take place? ( euk. And pro. )

Answer 3

Euk: nucleaus
Pro: Nucleoid

Question 4

What is the sidedness of DNA?

Answer 4

5’ end has a phosphate, 3’ end has a hydroxyl

Question 5

What is the directionality of DNA?

Answer 5

Read 3’ to 5’

Synthesized 5’ to 3’

Question 6

What does helicase do?

Answer 6

Unwind DNA

Question 7

What does topoisomerase do?

Answer 7

Relaxes the supercoiling in front of the replication fork

Question 8

What does primase do?

Answer 8

Synthesizes the RNA primer

Question 9

What does DNA polymerase do?

Answer 9

Synthesizes new strands of DNA

Question 10

What does ligase do?

Answer 10

Joins fragments of the lagging strand

Question 11

Where does transcription take place? (Euk and Pro)

Answer 11

Euk: nucleus
Pro: Nucleoid

Question 12

Do RNA and DNA have the same directionality?

Answer 12

Yes

Question 13

What is a template strand?

Answer 13

The strand being read (Antisense, non coding, minus strand)

Question 14

What doe RNA polymerase do?

Answer 14

Makes mRNA molecules in 5’ to 3’

Question 15

What is a promoter in transcription?

Answer 15

The site where RNA polymerase binds to start

Question 16

What are transcription factors?

Answer 16

Activators/Inhibitors that turn the gene on/off

Question 17

What is a 5’ guanine cap?

Answer 17

Signals the start of the mRNA transcription for ribosomes for bind. Facilitates in exporting from the nucleus.

Question 18

What is a 5’ guanine cap?

Answer 18

Signals the start of the mRNA transcription for ribosomes for bind

Question 19

What is gene splicing in transcription?

Answer 19

Removal of introns from the mRNA transcript

Question 20

What is a poly-A tail?

Answer 20

Inhibits degradation from hydrolytic enzymes in the cytosol

Question 21

Where is RNA translated?

Answer 21

Ribosomes

Question 22

What are the ribosome subunits, and their function?

Answer 22

Small: binds to tRNA
Large: binds to mRNA

Question 23

What is a point mutation and frame shift?

Answer 23

Point mutation: one nucleotide base switched for another
Frame shift: nucleotide base inserted/deleted

Question 24

What’s the difference between silent, missense, and nonsense mutations?

Answer 24

Silent: no change in amino acid
Missense: different amino acid produced
Nonsense: changes to stop codon

Question 25

What is a chromosomal mutation?

Answer 25

Mutation resulting in a rearrangement of abnormal number of chromosomes

Question 26

What is an operon?

Answer 26

Unit of DNA with a cluster of functioning genes

Question 27

What is a promoter in an operon?

Answer 27

The site where DNA polymerase binds

Question 28

What is an operator in an operon?

Answer 28

Site where repressor binds

Question 29

What is a repressable operon?

Answer 29

Genes stay on until repressor binds to operator. Repressor binds when the gene is no longer needed; usually involves synthesizing molecules.

Question 30

What is an inducible operon?

Answer 30

Operon where the repressor will stay bound until told otherwise.

Question 31

What is gel electrophoresis?

Answer 31

A way to separate the nucleotide bases. DNA samples put into wells in the (-) charged section of gel (DNA IS NEGATIVE). Nucleotide bases will be pulled through the gel to the (+) side. Larger nucleotide bases won't go as far because they can't weave through the gel pores as easy.

Question 32

What is the purpose of polymerase chain reactions (PCR)? What are the main steps?

Answer 32

To make multiple copies of a DNA strand. 1. Heating 2. Cooling 3. Annealing

Question 33

What is bacterial transformation?

Answer 33

Inserting new genetic material (plasmid) into bacteria

Question 34

What is DNA sequencing?

Answer 34

Using radioactive material to determine the specific nucleotide bases in the DNA sequence