Week 1 DNA & RNA

Question 1

3 stages of transcription

Answer 1

1. Initiation
2. Elongation
3. Termination

Question 2

The 2 ends present in primary transcript

Answer 2

5’ cap

3’ polyA tail

Question 3

Process of removing non-translated parts of nascent RNA (name of enzyme responsible, parts removed & stayed)

Answer 3

Splicing by spliceosome

introns are removed, creating mature mRNA with only exons

Question 4

3 regions in large ribosomal subunit

Answer 4

A-site: tRNA binds to codon
P-site: amino acid form peptide bond with the one in A-site
E-site: uncharged tRNA exits

Question 5

2 strands in template DNA involved in transcription

Answer 5

1. Coding strand

2. Template strand (complementary with mRNA)

Question 6

What are genotype and phenotype?

Answer 6

genotype: exact pairing of alleles
phenotype: expression of the trait

Question 7

what is the compound formed by initiator tRNA, small ribosomal subunit and large ribosomal subunit?

Answer 7

Translation complex

Question 8

Enzyme responsible for RNA transcription

Answer 8

RNA polymerase

Question 9

What is nucleosome and what is its function?

Answer 9

Nucleosome: DNA wrapping around histone core proteins
Function:
regulate gene expression by controlling which DNA to be exposed to RNA polymerase

Question 10

What are the histone core proteins? How many are there in a single nucleosome?

Answer 10

H2A, H2B, H3, H4

8 proteins in total (2 copies of each)

Question 11

How many RNAs are in CRISPR and their names

Answer 11

2 short RNAs:

1. guide RNA
2. tracr RNA - form complex with Cas9 protein

Question 12

Which type of amino acid are proteins made up of?

Answer 12

L-alpha amino acids

Question 13

What is the protein that aids in protein folding?

Answer 13

Chaperone

Question 14

What are fibrous and globular proteins?

Answer 14

Fibrous proteins: insoluble

Globular proteins: soluble

Question 15

What is the amino acid that can form disulphide bridges?

Answer 15

Cysteine

Question 16

3 Categories of genetic variations

Answer 16

1. Copy Number variation: affect whole arm of chromosome (gain or lose whole arm)
2. Structural Variation: affect large segments of chromosome
3. Sequence Level Variation: affect one to few base pairs within chromosome

Question 17

How many types of structural variations are there? What are they?

Answer 17

4 types

1. Deletion
2. Duplication
3. Inversion
4. Translocation

Question 18

How many types of sequence level variations are there? What are they?

Answer 18

2 Types:
1. single nucleotide polymorphism (SNP): 
only 1 base pair affected
2. insertions/deletions (indel):
affect > 1 base pairs