Lec 3

Question 1

Define RNAi

Answer 1

Is the silencing of gene expression at the post-transcriptional level by small regulatory RNAs

Question 2

Describe what is RNAi

Answer 2

RNAi uses PTGs ( post transcriptional gene silencing)

The best known types of RNAi act by targeting mRNA in the cytoplasm

Question 3

Define PTGS

Answer 3

It is the post transcriptional gene silencing

A cellular process that can silence gene expression at a post transcriptional level by small regulatory RNAs

This is an important pathway used to regulate gene expression in many organisms

Question 4

What are small regulatory RNAs?

Answer 4

Specialised RNAs that prevent expression of specific genes using complementary base pairing

They are very small - 21-30 nts
Single stranded

2 classes

1. miRNA
2. siRNA

Question 5

What are classes of small regulatory RNAs?

Answer 5

2 classes

1. Micro RNA (miRNA)
2. Small interfering RNA (siRNA)

Question 6

What are the types of non-coding RNA

Answer 6

2 types

1. Housekeeping non coding RNA
2. Regulatory RNAs

1. Housekeeping non-coding RNAs are usually expressed constituitively 
Contains 3 classes
1. tRNA
2.rRNA
3. Small nuclolar RNA (snoRNA)

2. Regulatory RNAs have 3 main classes
3. Long non-coding RNA
4. Small regulatory RNAs
5. non-coding RNA from pseudogenes

Small regulatory RNAs have 2 classes

1. MiRNA
2. siRNA