2.5 Coding and Non-coding RNA Flashcards Preview

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Flashcards in 2.5 Coding and Non-coding RNA Deck (45)
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1

What was the nature of the defect that caused hemophilia in the family of Tsar Nicholas?

Defect in splice site caused inactivation of hemophilia gene. Point mutation.

2

What is the concept of collinearity and noncollinerity.

Suggests that a continuous sequence of nucleotides in DNA encodes a continuous sequence of amino acids in a protein.

3

What are euk genes? noncolinearity or colinearity?

Noncolinearity

4

How did we find out that euk genes were noncolinear?

By hybridizing DNA and mRNA

5

How did we find out that euk genes were noncolinear?

By hybridizing DNA and mRNA

6

Why are euk genes noncolinear?

The coding sequences (exons) of most euk genes are disrupted by noncoding introns.

7

What is the splicing mechanism for Group I introns?

self splicing

8

What is the splicing mechanism for Group II introns?

Self splicing

9

What is the splicing mechanism for Nuclear pre-mRNA introns?

Spliceosomal

10

What is the splicing mechanism for tRNA introns?

Enzymatic

11

What does a gene include?

1. DNA seq that code for exons and introns. 2. Seq at the beginning and end of RNA that are not translated into a protein, including the entire transcription unit (promoter, RNA coding seq, terminator)

12

What is the structure of mRNA?

5' UTR (where 5' cap is), Protein coding region and 3' untranslated region which is site if microRNA binding. (poly a tail)

13

The splicesome must know what in order to splice?

The consensus sequences on the 5' and 3'

14

What does the addition of 5' cap do?

Helps binding of ribosome to 5' end of mRNA, increases mRNA

15

What does the addition of polyA tail do?

Increases stability of mRNA, helps binding of ribosome to mRNA.

16

What is the seq of events for splicing? 5 steps

1. 5' site recognized and brings proteins in to do cutting. 2. 5' bent around and attache to A. 3. 3' end cut. 4. intron released. 5. Exons spliced together.

17

Where does RNA splicing take place?

Within the spliceosome

18

What is nuclear organization?

intron removal, mRNA processing, and transcription take place at the same site in the nucleus.

19

Pertaining to alternative splicing, what does it depend on?

Where the 3' cleavage site is

20

What is RNA editing?

Coding seq altered after transcription

21

What are guide RNAs?

Responsible for RNA editing. They change seq of a message POST transcriptionally, so that it is slightly modified . Thus making significant changes in amino acids.

22

When is mature euk mRNA produced?

When pre-mRNA is transcribed and undergoes sever types of processing

23

What two things do siRNAs and microRNAs have?

Dicer and RISC.

24

What does Dicer do?

Dicer cleaves dsRNA and pre-miRNA into short ds RNA fragments (siRNA and microRNA)

25

What is RISC?

RNA-induced silencing complex

26

What do siRNAs do?

Interfere with the expression of specific genes with complementary nucleotide sequenced by degrading mRNA after transcription. Preventing translation.

27

Which is more common? siRNA or microRNA?

siRNA

28

What is the origin of siRNA?

mRNA, transposon, or virus

29

What is the origin of miRNAs?

RNA transcribed from distinct gene

30

What is siRNA cleaved from?

RNA duplex or ssRNA that forms long hairpins