Nucleotides 1

Question 1

How does H1 stabilize the chromatin fibers

Answer 1

by binding to both nucleosome and linker dna

Question 2

negative and positive charge of dna and histone resp reason

Answer 2

negative - phosphates {DNA}
positive - lysine and arginine {histones}

Question 3

mitochondrial dna

Answer 3

circular
doesn’t utilize histones

Question 4

histones in octamer

Answer 4

H2A H2B H3 H4

Question 5

Heterochromatin

Answer 5

Darker
Sterically inaccessible
highly condensed
increased methylation
decreased acetylation
Barr bodies visible on periphery

Question 6

Methylation

Answer 6

changing expression without changing sequence

Question 7

functions of methylation

Answer 7

aging
carcinogenesis
genomic imprinting
transposable element repression
X chromosome inactivation {lyonization}

Question 8

Repression of gene transcription

Answer 8

Methylation with gene promoter {CPG islands}

Question 9

Disease of dysregulated DNA methylation

Answer 9

Fragile X syndrome

X is fragile cause its being expressed a lot

Question 10

Histone methylation

Answer 10

Mostly repression
depends on location
Methylation of lysine and arginine residues

Question 11

Histone Acetlyation

Answer 11

Removes positive charge of histone and increases transcription

Question 12

Disease of acetylation

Answer 12

thyroid hormone synth is altered by acetylation of receptor

Question 13

Disease of deacetylation

Answer 13

Altered gene expression of Huntington disease

Question 14

Nucleoside

Answer 14

base plus deoxyribose

Question 15

Nucleotide

Answer 15

nucleoside plus phosphate

Question 16

energy source of nucleotide

Answer 16

5’ end bearing triphosphate

Question 17

Deamination of cytosine

Answer 17

Uracil

Question 18

Deamination of adenine

Answer 18

Hypoxanthine

Question 19

Deamination of Guanine

Answer 19

Xanthine

Question 20

Deamination of 5’methylcytosine

Answer 20

Thymine

Question 21

Uracil to thymine

Answer 21

Methylation

Question 22

Amino acids for purine synthesis

Answer 22

Glycine
Aspartate
Guanine {GAG}

Question 23

_____ are thin filamentous proteins that form the nuclear lamina and create a dense protein web within the nucleus

Answer 23

Lamin Proteins

Question 24

Chromatin is usually made up of (number)____ chromosomes in humans.

Answer 24

46