DNA 3 Strcuture

Question 1

What is supercoiling

Answer 1

Over or underwounding of DNA caused by straining

Question 2

Supercoiling happens easiest when

Answer 2

DNA Ends aren’t free so in circular bacteria DNA and when eukaryotic DNA is anchored

Question 3

Supercoiling relies on what protein

Answer 3

Topoisomeres

Question 4

DNA, histones and non histones form what

Answer 4

Chromatin

Question 5

Eu chromatin is

Answer 5

Less condensed DNA

Question 6

Hetero chromatin is

Answer 6

Highly condensed DNA

Question 7

which chromatin forms majority of chromosomes

Answer 7

Euchromatin

Question 8

Which chromatin forms at the centromeres and telomere

Answer 8

Hetero

Question 9

Histones have what charge

Answer 9

Positive

Question 10

Histones attract what

Answer 10

Negative charge on phosphate of DNA

Question 11

H1 is what

Answer 11

High lysine

Question 12

H2A and H2b Is what

Answer 12

Moderate lysine

Question 13

H3 and H4 is what

Answer 13

High arginine

Question 14

Nucleosome is what

Answer 14

Core particle of octomer of histones wrapped around by strand of DNA 1.65 times

Question 15

How does the DNS wrap around the histones

Answer 15

Supercoiling, left handed

Question 16

What does H1 do

Answer 16

Keeps DNA in place

Question 17

Chromatosome is what

Answer 17

H1 + Nucleosome

Question 18

What’s the next level of packing after chromatosomes

Answer 18

Loops, solenoid?

Question 19

Centromere

Answer 19

Constricted region where spindle fibres join and split chromo

Question 20

Plasmids

Answer 20

Small circular DNA that doesn’t have centromere

Question 21

Centroid sequences

Answer 21

Binding sites for proteins thAt function as the kinetochore

Question 22

Chromosomes must have what for anaphase to star

Answer 22

Centromere

Question 23

Telomere help prevent what

Answer 23

Degradation and attachment to other chromosomes

Question 24

Name 3 modifications

Answer 24

Acetylation, phospholorstion, methylation

Question 25

Euchromatin leads to what type of gene expression

Answer 25

Increased gene exp

Question 26

Euchromatin to hetero is what enzyme

Answer 26

Histone deactylase

Question 27

Hetero to eu is

Answer 27

Acetyl transferase

Question 28

Acetylation is what

Answer 28

Removes positive charge on histones and so decreases interaction between histones and DNA

Question 29

Name 2 chromosomes affected by telomer fusions

Answer 29

13 Parsi syndrome and 21 DS

Question 30

Tertiary structure is what

Answer 30

Higher folding that allows DNA to be condensed