Nucleic Acids

Question 0

Nucleotide

Answer 0

A base, sugar, and phosphate

Question 1

Location of DNA

Answer 1

The nucleus

Question 2

Nucleoside

Answer 2

Just a base and sugar

Question 3

Why is DNA so strongly held together?

Answer 3

All pairs have either double or triple hydrogen bonds and the planar bases allow more bonds per volume

Question 4

DNA backbone

Answer 4

Phosphate backbone linked by phosphodiester bonds

Question 5

The relatively stronger base pair

Answer 5

Cg, as it has three h bonds

Question 6

Groovy, man

Answer 6

Minor and major groove. Most DNA contacts made in major groove, where there is more room

Question 7

Three DNA conformations

Answer 7

B: right handed, normal
A: right handed, more compact, found in DNA RNA hybrids
Z: left handed, found transiently, during transcription

Question 8

Karyotype

Answer 8

The display of all 46 human chromosomes

Question 9

Chromosomes can be distinguished by

Answer 9

Size, staining patterns, and fish colour

Question 10

A gene contains

Answer 10

The DNA sequence that encodes the structural components of a gene product and regulatory elements that control its expression (promoter)

Question 11

Use of fish

Answer 11

Diagnosing chromosomal conditions

Question 12

Locus

Answer 12

A specific location on a chromosome

Question 13

Heterozygous vs homozygous alleles

Answer 13

If two genes functionally differ, they are heterozygous

Question 14

Homologous chromosomes

Answer 14

Corresponding chromosomes

Question 15

Conserved synteny

Answer 15

Same genes in the same order, but in different species

Question 16

Chromatin

Answer 16

A histone DNA complex that contains a large amount of arg and lys, the arg and lys neutralize the negatively charged DNA backbone

Question 17

Nucleosome

Answer 17

Basic unit of DNA packaging in eukaryotes. Basic unit of chromatin. DNA wound around histones

Question 18

Histone tails

Answer 18

Regulate histone structure and are subject to covalent modifications. Modified by acetylation and methylation of lysines and by phosphorylation of serines. HATs add histone acetyl groups and loosen up genes for expression. HDACs take off and tighten

Question 19

HATs

Answer 19

Histone acetyltransferases. Loosen up genes for expression

Question 20

HDACs

Answer 20

Histone deacetyltransferases. Silence genes by taking off acetyl groups. HDAC inhibitors have uses in anti cancer drugs, by stopping suppression of anti cancer genes.

Question 21

Histone acetylation

Answer 21

Crucial in destabilizing chromatin structure for replication. Acetyl group removes overall positive charge of lysine. Enzymes that modify are tightly regulated

Question 22

Euchromatin

Answer 22

Good to go. Open for transcription. Acetylation of tail histones is associated with euchromatin

Question 23

Heterochromatin

Answer 23

No go. Highly condensed, associated with de-acetylation. Can include HDACs like SIR proteins

Question 24

RNA

Answer 24

Runs 3’-5’.
Single stranded, but can form secondary and tertiary structures by base pairing upon itself. These looped regions are important for binding proteins and other molecules.
Can act as enzymes as ribozymes
M, r, and t are involved in protein synthesis

Question 25

mRNA

Answer 25

Messenger, codes for proteins

Question 26

rRNA

Answer 26

Ribosomal. Forms basic structure of ribosome and catalyzes protein synthesis

Question 27

tRNA

Answer 27

Transfer. Adapters between mRNA and aas. All have cloverleaf structure. Anti codon site binds to codon on mRNA . Have some modified nucleotides like ribothymidine. 3’ aa attachment site.

Question 28

snRNA

Answer 28

Small nuclear. Nuclear processes, including splicing of pre mRNA.

Question 29

snoRNA

Answer 29

Small nucleolar. Process and chemically modify mRNA

Question 30

scaRNA

Answer 30

Small cajal. Modifiy snoRNA and snRNA

Question 31

miRNA

Answer 31

Micro. Regulate gene expression by blocking translation of selected mRNA and chromatin formation. Key functions in cell differentiation. Mutations can cause cancer. Similar to siRNA.

Question 32

siRNA

Answer 32

Small interfering. Turn off gene expression by degrading mRNAs and establishing compact chromatin

Question 33

Processed mRNA

Answer 33

A 5’ guanosine cap, start codon, stop codon, poly a tail

Question 34

Ribosomes

Answer 34

Ribonecleoprotein structures on which protein synthesis occurs. Contain rRNA. Many loops and extensive base pairing.