Chapter 3 Molecular Biology

Question 1

mRNA role

Answer 1

Carries genetic code to cytoplasm for controlling type of protein formed

Question 2

Transfer RNA role

Answer 2

Transports activated amino acids to the ribosomes to be used in assembling the protein molecule

Question 3

Ribosomal RNA role

Answer 3

Forms ribosomes, in which protein molecules are assembled.

Question 4

Micro RNA miRNA role

Answer 4

Single stranded RNA molecules of 21-23 nucleotides that can regulate gene transcription and translation

Question 5

DNA strand that is the opposite of mRNA transcript

Answer 5

DNA template strand

Question 6

DNA strand that is the same as the mRNA strand we get

Answer 6

Nontemplate or coding strand

Question 7

Parts of DNA that are used, parts we will splice

Answer 7

Exons

Introns

Question 8

Poly A tail

Answer 8

Longer the tail is the longer it will keep functioning. RNAse chews it up, once A’s are done and stuff codes for protein it’s done

Question 9

MiRNA looks for what to cut out

Answer 9

Introns

Question 10

How free ribosomes and bound ribosomes differ

Answer 10

Free ones have proteins that remain in cytoplasm. Cells that synthesize proteins are to remain here

Segregated in rough ER. Proteins produced here are injected into interior of organelle through its membrane. Way of separating undesirable effects from reaching cytoplasm

Question 11

What a signal peptide does

Answer 11

Binds to a signal recognition particle. Ribosomes bind to RER by interacting with SRP and a ribosomal receptor. These interactions cause opening of a pore through which protein moves into RER

Question 12

How we regulate gene expression

Answer 12

Promoter elements allow us to find basal promoter containing TATA box (where Ts and As are) and easier to cut proteins we want to make

Question 13

What to activators to

What do depressors do

Answer 13

Protein that binds to DNA and allows polymerase to bind to it and gets polymerase to where it needs to be to start its job

Prevents RNA polymerase from expressing a gene

Question 14

What do zinc fingers do

Answer 14

Bind protein to a DNA. They are part of activator that binds to a specific piece of DNA and goes between base pairs

Question 15

What do leucine zippers do

Answer 15

Have hydrophobic leucine residues on one side that allows them to align with each other. Another way of binding protein to DNA

Question 16

What identical in DNA

What’s different

How to tell difference between

Answer 16

Phosphates

Nucleotides in middle

Get in middle of base pair and probe it

Question 17

Glutamine side chain forms ____ bonds with ___. ___ form with other base pairs

Answer 17

Hydrogen
Adenine
Won’t

Question 18

Arginine forms ___ bonds with ____

Answer 18

Hydrogen

Guanine

Question 19

Role of steroid hormone receptors

Answer 19

Binds to binding site and makes activator work or not work.

Question 20

Steroid receptors have 3 important parts of the protein:

Answer 20

Hormone bonding domain (binds steroid)
DNA binding site 
(Specific part of DNA)
Transcription activator that binds to RNA polymerase
(Attracts RNA polymerase)