Brainscape's Knowledge GenomeTM

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


See full index

MGD > Lecture 1.1 Chromosomes and DNA > Flashcards

Lecture 1.1 Chromosomes and DNA Flashcards

1
Q

what are genes?

A

portions of DNA which sit on chromosomes in the nucleus of a cell

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

what are proteins?

A

amino acid’s joined together, which are usually in the cytoplasm of the cell

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

what is gene expression?

A

the process of moving from a gene on DNA to a protein in the cytoplasm

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

what is the general process of gene expression?

A

DNA -> RNA -> Protein

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

where is DNA located?

A

in the nucleus of a cell

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

how can we view a chromatin?

A

through an electron microscope

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

what needs to happen to chromosomes before viewing them through a light microscope?

A

stained, condensed and replicated ready for division

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

what is a euchromatin? state 2 features of it.

A

lightly packed form of chromatin which is not wound together as much as heterochromatin. the genes are expressed as proteins have access to DNA and it is shaded light on the micrograph.

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

what is heterochromatin? state 2 features of it.

A

tightly packed form of chromatin which is highly packaged. the genes are not expressed and it is shaded dark on a micrograph

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

describe the 6 steps to package DNA in a chromosome?

A
  1. complementary base pairs form
  2. DNA double helix forms
  3. DNA wounds and loops around histone proteins therefore there is a bundle of protein and DNA
  4. nucleosome is formed and wounds together to form…
  5. a solenoid which is looped and folded to make…
  6. a chromosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe the “beads on a string” structure.

A

double stranded DNA wraps around the histone core. many loops of DNA around many histones to reduce the length of DNA. the DNA is accessible on various points of the string to allow gene expression.

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

what is a solenoid fibre?

A

histones and nucleosomes come together in a tightly packed structure of “beads on a string”.

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

how does a solenoid fibre allow gene expression?

A

there is access through the middle so individual gene expression proteins can go through the middle of the solenoid. can also access the DNA along the outer edge of each of the nucleosomes.

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

what are solenoid loops?

A

solenoid fibres loop around in a helical structures and are tightly packed therefore not accessible.

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

how are chromosomes formed?

A

solenoid fibres loops around in helical structures called solenoid loops, and these get condensed into condensed solenoid loops (large amount of material in a small space), these form into chromosomes

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

rearrange these in order of smallest to biggest:

solenoid loops, chromosomes, solenoid fibres, consentes solenoid loops

A

solenoid fibres, solenoid loops, condensed solenoid loops, chromosome

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

what is chromatin?

A

a complex of DNA and proteins which forms chromosomes. in its extended form, it looks like “beads on a string”

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

where is the solenoid fiber located in a chromatin?

A

in the heterochromatin where the genes are not expressed.

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

where is the “beads on a string” located in a chromatin?

A

in the euchromatin where the genes are expressed.

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

explain the genes present in a heterochromatin and euchromatin.

A

there are different genes present in the heterochromatin to the euchromatin because it depends on the function of the cell and therefore which genes need to be expressed for the cell to be able to do that. those genes will be in the euchromatin.

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

how many human chromosomes do we have?

A

22 pairs of autosome chromosomes. 1 pair of sex chromosomes. total 24 pairs of chromosomes.

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

why is packaging DNA important in humans?

A

because we need to store the large amounts of DNA in an efficient way so we can also access it.

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

on a general level, what are DNA and RNA?

A

nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are nucleic acids?

A

polynucleotides: aka a chain of nucleotides/linear polymers of nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is a nucleotide composed of?

A

nitrogenous base + pentose sugar + at least 1 phosphate group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the difference between nucleoside and nucleotide?

A

nucleoside does not contain any phosphate groups, where as nucleotide does

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the difference between the pentose sugar of DNA and RNA?

A

in RNA, on the 2 prime carbon a hydroxile group is present, where as on the 2 prime carbon in DNA, a deoxy group is present aka just a hydrogen (lost the oxygen)

28
Q

why is the difference between the pentose sugar of DNA and RNA important?

A

because it effects the functionality of DNA and RNA

29
Q

what are the nitrogenous bases of DNA?

A

cystosine, guanine, adenine and thymine

30
Q

what are the nitrogenous bases of RNA?

A

cytosine, guanine, adenine and uracil

31
Q

which nitrogenous bases are purines?

A

adenine and guanine: have 2 ring structure

32
Q

which nitrogenous bases are pyrimidines?

A

cytosine, thymine and uracil: one right structure

33
Q

what is the nucleotide for adenine in DNA called?

A

deoxyadenoSIne monophosphate (dAMP)

34
Q

what is the nucleotide for adenine in RNA called?

A

adenoSIne monophosphate (AMP)

35
Q

what is the nucleotide for guanine in DNA called?

A

deoxyguanoSIne monophosphate (dGMP)

36
Q

what is the nucleotide for guanine in RNA called?

A

guanoSIne monophosphate (GMP)

37
Q

what is the nucleotide for cytosine in DNA called?

A

deoxycyiDIne monophosphate (dCMP)

38
Q

what is the nucleotide for cytosine in RNA called?

A

cytiDIne monophosphate (CMP)

39
Q

what is the nucleotide for thymine in DNA called?

A

deoxythymiDIne monophosphate (dTMP)

40
Q

what is the nucleotide for thymine in RNA called?

A

thymine is not present in RNA

41
Q

what is the nucleotide for uracil in RNA called?

A

uriDIne monophosphate (UMP)

42
Q

what is the nucleotide for uracil in DNA called?

A

uracil is not present in DNA

43
Q

what bond joins nucleotides together?

A

phosphodiester

44
Q

what does the polarity in a chain on nucleotides do?

A

gives direction

45
Q

which direction do chains of nucleotides go in?

A

5’ to 3’

46
Q

what is on the 5’ end of the polynucleotide?

A

the phosphate group

47
Q

what is on the 3’ end of the polynucleotide?

A

the OH group

48
Q

which bond joins the pentose sugar to the nitrogenous base in nucleotides?

A

glycosidic bond

49
Q

describe the structure of DNA.

A

2 complementary polynucleotide chains which are antiparallel

50
Q

what joins the 2 polynucleotide chains in DNA?

A

the hydrogen bonds between the nitrogenous bases (complementary base pairing)

51
Q

how many hydrogen bonds are present in adenine and thymine pairing?

A

2

52
Q

where are the 2 hydrogen bonds between adenine and thymine present?

A

between the hydrogen and oxygen & nitrogen and hydrogen

53
Q

state the polarity in the hydrogen bond between adenine and thymine.

A

H is partially positive charge and O&N are partially negative charge

54
Q

how many hydrogen bonds are present in cytosine and guanine pairing?

A

3

55
Q

where are the 2 hydrogen bonds between cytosine and guanine present?

A

between the oxygen & nitrogen, hydrogen & nitrogen and hydrogen & oxygen

56
Q

state the polarity in the hydrogen bond between cytosine and guanine.

A

H is partially positive charge and O&N are partially negative charge

57
Q

what is the difference between G&C vs A&T bonds?

A

G&C are slightly stronger H bonds bcs there are 3 H bonds present

58
Q

state the 2 secondary structures of RNA.

A

“hairpin” structure and “clover leaf” structure

59
Q

describe the “hairpin” secondary RNA structure.

A

a single strand of RNA loops on to itself to create a loop

60
Q

describe the “clover leaf” secondary RNA structure. where is it important?

A

multiple “hairpin”s within a single strand. important in tRNA.

61
Q

describe the spacing in a DNA double helix.

A

in 1 complete turn of DNA, there is a major and minor groove on the sides of the helix

62
Q

what is the accessibility of the major and minor grooves in DNA?

A

major groove is more accessible and minor grooves are not as accessible

63
Q

what is the function of grooves?

A

allow different ways of protein & machinery to access the DNA

64
Q

what does the sequence: 5’ACCT3’ show?

A

a single strand of polynucleotide sequence

65
Q

if the sequence: 5’ACCT3’ is shown in an exam, what does it mean?

A

the antiparallel complementary strand is present, but it’s not written. in this case it is 3’TGGA5’

66
Q

what are inherited diseases, genetically?

A

mutations, deletions or errors in genes

MGD (2 decks)

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