9.6 Chromatin, Transcription, RNA Processing Flashcards Preview

Foundations Exam 3 > 9.6 Chromatin, Transcription, RNA Processing > Flashcards

Flashcards in 9.6 Chromatin, Transcription, RNA Processing Deck (21):
1

the "poly-A addition signal" is integral for the 3' processing. What other sequence is?

a string of U or GU nucleotides

2

what disease is associated with incorrect splicing? (bood cells - incorrect expression of globin genes)

thalassemias

3

a nucleosome has _______ histone proteins, which forms a disk-like structure. The _____ is wrapped around the outside of this histone core and is held in place by histone _______.

8, DNA, histone H1

4

The exposed 5' end of the new RNA is modified by a methylated nucleotide (5' 7-methyl guanosine). What is this called?

the mRNA cap

5

how does a single gene generate multiple different proteins?

differential/alternative splicing

6

at the extreme 5' end of an intron, there is usually a "___-___" (nucleotide sequence)

G-U

7

what are the three functions of the mRNA cap?

1. binds to a protein complex which is important for translation
2. allows for recognition of mRNAs vs. other RNAs without caps
3. helps to protect the 5' end of the RNA from degradation

8

what is the "poly-A addition signal"

5' - AAUAAA - 3'

9

on the intron sequence, there is always an "_____" that signifies the branch point

A

10

a small family of basic proteins. They have a positive charge and thus interact strongly with the negative outside of DNA

histones

11

at the extreme 3' end of the intron, there is always a "__-__" (nucleotide sequence)

A-G

12

proteins that help facilitate splicing are called: _______

snRNPs

13

nucleosomes themselves are wrapped into a more elaborate structure/sprial called a _________

solenoid

14

the solenoid structure decreases DNA length by ____ fold

8

15

a _________ is added at the 3' end of a transcript

poly-A tail

16

describe the two main steps in the splicing of introns from transcripts

1. the branch point nucleotide attacks the 5' splice junction and cleaves the backbone at this point
2. The 3' OH of the first exon sequence then reacts with the 5' end of the next exon, to precisely excise the intron

17

the nucleosome decreases DNA length by ____ fold

5

18

the process of transcription starts with DNA and makes ____

RNA

19

in a gene, the __________ are expressed and the ________ are intervening regions, not expressed.

exons, introns

20

what protein lies outside the histone and is thought to hold the DNA in place?

histone H1

21

_____ is a disease resulting from incorrect expression of globin genes in blood cells. One mutation changed a ____ at the start of an intron into a GC, causing _____ splicing.

thalassemia
GU
incorrect