6. Nucleotides and transcription

Question 1

Describe the process of transcription and translation.

Answer 1

Transcription is the process of making an RNA copy of DNA code. This copy, called a messenger RNA (mRNA) molecule, leaves the cell nucleus and enters the cytoplasm, where it directs the synthesis of the protein which it codes for

Question 2

What’s the difference between RNA and DNA?

Answer 2

DNA is double stranded, RNA is single stranded
RNA contains ribose, DNA contains deoxyribose
DNA has H bonding between pairs
RNA has U (Uracil) instead of T (thymine)
Both made from 5’ to 3’ end

Question 3

Whats the start codon?

What are the stop codons?

Answer 3

• AUG, Methionine
• First codon in the transcribed mRNA that undergoes translation
• Stop codons UAA, UAG, UGA
• Number of codons = 4 bases (letters) ^ (3 spots)

Question 4

What’s Polymerization?

Answer 4

Combining two things to form a polymer.

Question 5

What are DNA and RNA polymerase?

Answer 5

• DNA polymerase helps produce a double-stranded DNA molecule during polymerization.
• RNA polymerase is an enzyme that helps produce a single-stranded RNA molecule during transcription.
• RNA polymerase separate/melts DNA so that mRNA can attach at promoter site

Question 6

Will RNA look like sense or template strand?

Answer 6

RNA reads from the template strand of DNA
mRNA will therefore resemble the sense strand (with U’s in the place of T’s)
*sense strand is also called non-template strand
DNA template = 3’-5’
DNA sense = 5’-3’
RNA grows from 5’-3’ against DNA 3’-5’

Question 7

Which bases will pair with each other?

Answer 7

A - T (or U for RNA)

C - G

Question 8

How do you get mRNA codons from DNA?

Answer 8

1. Look at DNA sense strand (5’-3’) and change all T’s to U’s
2. Look at DNA template strand (3’-5’) and match corresponding bases
   remember RNA binds to template strand and is going to resemble sense strand closely

Question 9

What are the four nucleotides?

Answer 9

Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)