lecture 3 (chapter 11)

Question 1

viral chromsome characteristics

Answer 1

• either DNA OR RNA, single OR double stranded
• circular

Question 2

baterial chromosome characteristics

Answer 2

• circular, double-stranded DNA compacted into nucleoid
• DNA is assocated with HU and H-NS DNA-binding proteins

Question 3

__ and ___ contain their own DNA

Answer 3

mitochondria, chloroplasts

Question 4

mtDNA characteristics

Answer 4

• double stranded (no chromosomal proteins)
• introns absent
• most genes are encoded on one strand

Question 5

cpDNA characteristics

Answer 5

• circular, double-stranded, free of associated proteins found in eukaryotic DNA
• has BOTH introns and duplications

Question 6

in vertebrate mitochondrial DNA, the two DNA strands vary in density. This implies…

Answer 6

that one strand is enriched in A’s and G’s while the other strand is enriched in T’s and C’s

Question 7

chromatin at interphase

Answer 7

eukaryotic chromosomes uncoil and decondense into chromatin

Question 8

chromatin during interphase

Answer 8

chromatin is dispersed throughout nucleus and replicated

Question 9

chromatin during cell division

Answer 9

coils and condenses back into visible chromosomes

Question 10

histone proteins

`

Answer 10

responsible for the first level of DNA packing in eukaryotic chromatin

Question 11

histone proteins contain large amounts of

Answer 11

lysine and arginine

Question 12

twists and turns of DNA superhelix encircle _

Answer 12

histones

Question 13

nucleosome consists of

Answer 13

DNA wound around a protein core of eight histones

Question 14

to allow replication and gene expression, chromatin must:

Answer 14

• relax compact structure
• expose regions of DNA to regulatory proteins
• have a reversal mechanism for inactivity

Question 15

acetylation enzyme

Answer 15

histone acetyltransferase (HAT)

Question 16

acetylation

Answer 16

addition of acetyl group to positively charged amino group on side chain

Question 17

acetylation changes net charge of protein by

Answer 17

neutralizing positive charge

Question 18

methylation enzyme

Answer 18

histone methyltransferase (HMT)

Question 19

methylation adds methyl groups to _ and _ residues in histones

Answer 19

argnine, lysine

Question 20

phosphorylation enzyme

Answer 20

kinase

Question 21

phophorylation adds phosphate groups to _ groups of amino acids _ and _ in histones

Answer 21

hydroxyl (-OH), serine, histidine

Question 22

CpG island

Answer 22

region of DNA where many cytosine guanine dinucleotides are present

Question 23

methylation of the cytosine within polynucleotide chains of DNA;

Answer 23

• forms 5-methyl cytosine
• negatively correlated with gene activity

Question 24

satellite DNA

Answer 24

many repeats of short sequences
* found at regions flanking centromeres

Question 25

rRNA genes

Answer 25

many copies of the same gene

Question 26

VNTRs

Answer 26

repeating DNA sequences 15 to 100 bp long
* found within in between genes

Question 27

STRs (short tandem repeats)

Answer 27

• consist of di-, tri-, tetra-, and pentanucleotides
• dispersed throughout genome