Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bio 302 > Chapter 5 > Flashcards

Chapter 5 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

what is a nucleotide composed of?

A

a sugar-phosphate covalently linked to a base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how are nucleotides linked?

A

covalently linked together into a polynucleotide chain, with sugar-phosphate backbone from which the bases extent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a DNA molecule composed of?

A

2 polynucleotide chains (DNA strands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how are DNA strands held together?

A

by hydrogen bonds between paired bases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how many h-bonds are formed between A & T?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how many h-bonds are formed between G & C?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how many rings do purines have?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how many rings do pyrimidines have?

A

single

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a base pair?

A

purine-pyrimidine pair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the 3’ end carries what?

A

an unlinked -OH group attached to 3’ position on sugar ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the 5’ end carries what?

A

a free phosphate group attached to 5’ position on sugar sing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how many base pair per turn?

A

10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is chromatin?

A

combination of DNA and proteins that make up the contents of the nucleus of a cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does chromosome painting do?

A

expose to a collection of fluorescent dye-labeled DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is a karyotype?

A

homologous chromosomes that are numbered and arranged in pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is inherited ataxia?

A

a disease that deteriorates motor skill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does ataxia do to chromosome 12?

A

one normal and one abnormal, longer with material from chromosome 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what strand encodes the information to make protein of RNA molecules?

A

coding strand, can be either strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

in humans majority of chromosome don’t carry critical info

A

junk DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens during interphase?

A

cell is actively expressing genes and DNA is replicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens during M phase?

A

chromosomes condense, gene expression ceases, and mitotic spindle forms from microtubules and other proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a nuclear envelope?

A

it forms around each chromosome set and the cell divides to produce 2 daughter cells in final step of M phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

where are the multiple origins of replication on a chromosome?

A

1 centromere, and 2 telomeres

24
Q

during interphase, DNA replicates at the origin of replication in which direction?

A

bi-directionally from the origins across the chromosome

25
Q

what do telomeres contain? why?

A

repeated nucleotide sequences that enable the ends of chromosomes to be replicated, also cap the end.

26
Q

why do telomeres cap the end of chromosomes?

A

prevent it from being mistaken by the cell as broken DNA in need repair

27
Q

how is the nuclear envelope supported?

A

by the nuclear lamina

28
Q

what is the nuclear lamina?

A

network of protein filaments that form a thin layer underlying the inner nuclear membrane

29
Q

what is the chromatin that appears as a mass with dense chromosomal regions called?

A

heterochromatin (dark region)

30
Q

what is heterochromatin?

A

is chromatin expressing little to no genes, and located under the nuclear envelope

31
Q

what is the large dark region inside the nucleus?

A

nucleolus

32
Q

what does the nucleolus contain?

A

contain the genes fro ribosomal RNA

33
Q

where is rRNA located?

A

on multiple chromosome, but clustered together in the nucleolus

34
Q

what are the proteins on eukaryotic chromosomes?

A

histones nad nonhistone chromosome proteins

35
Q

nucleosomes contain DNA wrapped around a core of how many histone modules?

A

8

36
Q

how many histones make up the nucleosome core.

A

4 small proteins with high proportion of + charged amino acids

37
Q

how does the + charge help the nucleosome?

A

helps the histone bind tightly to the - charged sugar-phosphate backbone of DNA

38
Q

what pulls nucleosomes together into the 30-nm fiber?

A

a linker histone (H1)

39
Q

what does Histon H1 consist of?

A

a globular region plus a pair of long tails at its c-terminal and n-terminal ends

40
Q

what does the globular region do?

A

constrains an additional 20 base pairs of DNA where it exits from the nucleosome core.

41
Q

why is the globular region important?

A

for the formation of the 30 nm fiber

42
Q

what are the two ways chromatin structure differ with degrees of extension or condensation?

A

heterochromatin and euchromatin

43
Q

heterochromatin is more condensed than what?

A

euchromatin

44
Q

what does the chromatin-remodeling complex do?

A

repositions the DNA wrapped around the nucleosome

45
Q

how does the chromatin-remodeling complex work?

A

protein machine that uses the energy of ATP hydrolysis to change the position of DNA

46
Q

what happens when the tightly bound DNA moves along the complex?

A

loosen the underlying DNA, making it more accessible to other protein

47
Q

multiple rounds of nucleosome sliding does what?

A

decondense chromatin

48
Q

what can dictate how to stretch of chromatin is treated by the cells?

A

the pattern of modification of histone tails

49
Q

histones can be modified by the covalent attachment of a # of different chemical groups:

A

acetyl group, methyl group, phosphate

50
Q

where do most modifications go on the tail?

A

n-terminal tails of histone

51
Q

different combinations of histone tail modifications can confer what?

A

a specific meaning on the stretch of chromatin on which they occur

52
Q

heterochromatin-specific modifications allow what?

A

heterochromatin to form and spread

53
Q

what can repressive modifications to the histone tail do?

A

attract heterochromatin-specific proteins that reproduce the same modifications on neighboring proteins

54
Q

repressive modifications allow heterochromatin to spread until?

A

it encounters a DNA barrier sequence that prevents heterochromatin spread

55
Q

how can an expression of a gene be altered?

A

by moving it to another location in the genome

56
Q

what is the position effect?

A

activity of a gene depends on its position along a chromosome

57
Q

how can an X chromosome be inactivated?

A

by heterochromatin formation

Bio 302 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions