Brainscape's Knowledge GenomeTM

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


See full index

Biology > DNA and RNA nucleic acid > Flashcards

DNA and RNA nucleic acid Flashcards

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

what are the types of nucleic acid?

A

Deoxyribonucleic acid
Ribonucleic Acid
these are both pentose sugar

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

why are they known as macromolecules?

A

they contain polymers and polynucleotides (made of smaller sub units : nucleotides)

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

what are nucleotides?

A

monomers of nucleic acid made of 3 components

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

what are the 3 components?

A

phosphate group
pentose sugar
nitrogen - containing base (organic)

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

how many types of N containing bases are there?

A

5 types, they are purine bases and pyrimidine bases

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

what are the purine Bases?

A

Adenine and Guanine

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

what are the Pyrimidine Bases?

A

Thymine, cytosine and uracil

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

what are the bases in DNA?

A
  1. Adenine 2. Thymine 3.Cytosine 4. Guanine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the bases in RNA?

A

1.Cytosine 2. Guanine. 3.Adenine 4.Uracil

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

where is DNA found?

A

in eukaryotic in the nucleus it is a double stranded polynucleotide

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

how do nucleotides join?

A

by condensation reaction between deoxyribose sugar and phosphate group of nucleotides known as sugar-phosphate back bone

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

why way do nitrogen containing base point?

A

sideways

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

where do the 2 strands go?

A

they run opposite to each other (anti parallel) held by H bonds between bases.

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

where must purine bases be?

A

always opposite a pyrimide base

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

what are some complementary base pairs?

A

Adanine:Thymine
Cytosine:Guanine

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

what is RNA?

A

it is single stranded it has uracil instead of Thymine

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

what are types of RNA?

A

mRNA
rRNA
tRNA

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

how is mRNA formed?

A

single strand formed into a helix

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

where is mRNA made?

A

in the nucleus passes into the cytoplasm then moves to the ribosomes

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

where is rRNA made?

A

in the nucleolus

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

where is rRNA found?

A

in the cytoplasm

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

what is rRNA used for?

A

to form ribosomes made of rRNA and protein

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

what is tRNA?

A

a clover leaf shape, one end attaches to specific amino acid other end has triplet of bases (anticodon) used in protein synthesis

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

what is tRNA used for?

A

to transfer information

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

how is DNA formed?

A

2 DNA strands run antiparallel. deoxyribose nucleic acid anti parallel strands twist into a double helix, joined by complementary base pairs.

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

what happens when cells divide?

A

each new cell must have copy of the same genetic material, DNA must replicate itself, this happens in the interphase

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

what happens in DNA replication?

A

two strands of DNA unwind and split H bonds break. then free nucleotides line up against DNA strands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how are nucleotides activated?

A

by phosphate group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

why does the enzyme DNA polymerase join?

A

forms 2 new DNA molecules, known as semi conservative theory,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what does each new DNA have?

A

an original strand and a new one this creates two identical sister chromatids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what were the 3 theories in 1950s?

A

conservative replication
dispersive replication
semi conservative replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

who provided the evidence?

A

meselsohn + stah replication theory was accepted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what did the evidence show?

A

each new DNA strand was a template for the synthesis of the new strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how was this proved?

A

they used E.coli and nitrogen isotopes N14 (light) and N15(heavy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what was the experiment?

A

E.coli was grown on N15 for first generation, all nitrogen bases were N15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what happened to the resulting DNA?

A

it was split in a centrifuge and 1 heavy band was obtained

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

where was this heavy band transferred to?

A

to N14 medium and allowed for 3 generation of replication . the DNA was split from each generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what controls the cells activities?

A

chemical reactions all of these are controlled bye enzymes and therefore proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what makes up protein molecules?

A

sequences of DNA bases and therefore DNA controls cell activities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is the name for one sequence of bases that code for one protein?

A

gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what are proteins made of?

A

amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what does protein shape depend on?

A

folding which depends on sequence of amino acids - primary structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what does the sequence of bases in DNA control?

A

the sequence that amino acids join when a protein is made on ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

how many amino acids are there?

A

20

45
Q

how are amino acids coded for?

A

by sequence of 3 bases on DNA molecules

46
Q

what is a set of 3 bases known as?

A

codon or triplet code

47
Q

what is particular about sequence on a DNA molecule?

A

it is read in a certain direction

48
Q

why is one of the two strands used?

A

it is a template

49
Q

why three bases?

A

genetic code 64 triplets of nucleotides. DNA has 4 bases to code for 20 amino acids, meaning each base cant code for one amino acid. 3 bases makes 64 codes more than enough for 20 amino acids

50
Q

how triplet code determined?

A

by series of RNA experiments

51
Q

what is degenerate code?

A

it is more than one triplet code for amino acids

52
Q

what was discovered about 3 codons?

A

they do not code for amino acids - stop codons

53
Q

what is usually a start codon?

A

AUG

54
Q

what is special about the code?

A

it is non overlapping

55
Q

what are all codons?

A

universal same for all organisms

56
Q

what does part of DNA molecule code for?

A

polypeptide and it is a gene

57
Q

how many do humans have?

A

140,000 human genome has been mapped

58
Q

how is info sent from DNA to cytoplasm?

A

by transcription

59
Q

what is info in DNA used for?

A

to build molecules of RNA

60
Q

what does mRNA do?

A

takes message from DNA to ribosomes in cytoplasm

61
Q

what is the first stage of transcription?

A

DNA double helix unwinds and unzips, H bonds between base pairs break.

62
Q

what is the second stage of transcription?

A

Free RNA nucleotides align with exposed DNA, on one strand of the DNA

63
Q

what is this strand?

A

the template or coding strand

64
Q

then what happens in stage 3?

A

RNA polymerase links RNA nucleotides a single strand of mRNA forms the DNA helix forms behind it

65
Q

what does mRNA contain?

A

codons

66
Q

what does mRNA do?

A

it is small enough to leave through nuclear pores attaches to ribosome

67
Q

what is tRNA ?

A

chain of nucleotides

68
Q

what is the structure of tRNA?

A

clover leaf shape
Hairpin Bend
H bonds to hold it in shape
anticodon - different for each amino acid amino acid binding structure

69
Q

what happens translation?

A

mRNA molecule attaches to ribosome, tRNA molecules bind with exposed mRNA bases. then ribosomes hold two amino acids together as polypeptide bond.

70
Q

how is this catalysed?

A

by an enzyme

71
Q

what happens next?

A

ribosomes moves along mRNA read next codon, tRNA is released passes back to cytoplasm to get another amino acid.

72
Q

how far does the polypeptide chain grow?

A

until stop codon is and new protein molecule is formed

73
Q

why do organism show variation?

A

species have similar characteristics but aren’t identical, have same genes different alleles

74
Q

why are there variations in phenotype?

A

due to environment and genotype

75
Q

what are 4 cause of variation?

A

crossing of non sister chromatids during prophase 1 meiosis
independent assortment of bivalents in meta phase 1 meiosis
random fusion of gametes during sexual reproduction
DNA mutation - chromosome and gene

76
Q

what is mutation?

A

change in composition of DNA

77
Q

what is chromosome mutation?

A

change in chromosome structure number of chromosomes

78
Q

what is gene mutation?

A

change in base sequence of gene

79
Q

what can gene mutation lead to?

A

a new allele if allele has selective advantage it can transfer to off spring

80
Q

what is translocation?

A

when section of chromosome lost to other chromosomes

81
Q

what is polysomy?

A

whole chromosomes are duplicated chromosomes fail to separate in anaphase 1

82
Q

what is polyploidy?

A

set are chromosomes are duplicated

83
Q

what do mutations do?

A

change the order of DNA bases in gene

84
Q

what are 3 ways it can occur?

A

Substitution
Addition
Deletion

85
Q

what is substitution?

A

nucleotide is replaced by different one (sickle cell anemia)

86
Q

what is Addition?

A

extra nucleotides are added

87
Q

what is deletion?

A

nucleotides are lost ( cystic fibrosis)

88
Q

what do addition and deletion do?

A

alter amino acid sequence change protein structure

89
Q

what is nonsense mutation?

A

it is caused by substitution and makes a stop codon causing protein to be smaller

90
Q

what is missense mutation?

A

caused when substitution base makes protein with different amino acid sequence

91
Q

what is silent mutation?

A

when base codes for the same amino acid

92
Q

name 2 mutagens that increase chance?

A

radiation- xray

chemicals - benzopyrene in smoke

93
Q

what is a carcinogen?

A

is a mutagen that mutates genes which controls mitosis leading to uncontrolled cell division (cancer)

94
Q

what is sickle cell anaemia?

A

globular protein with quaternary structure, it has 4 polypeptide chains per molecule, 2 alpha chains and 2 beta chains.

95
Q

what does each chain contain?

A

a haem group each of these has Fe2+ ion

96
Q

what binds to haem group?

A

O2 molecule, 4O2 molecules transported per haemoglobin molecule, reversible O2 binding, it has an s shaped binding curve

97
Q

what is Phenylketonuria?

A

the phenylalanine hydroxylase hepatic enzyme is affected

98
Q

what is phenylalanine converted to?

A

to the amino acid tyrosine, phenylalanine concentration increases

99
Q

why are people pale?

A

low tyrosine levels

babies are tested - High PKU prevent normal brain development

100
Q

why use genetic diagrams?

A

allows us to predict characteristics of offspring from 2 parents

101
Q

what is monohybrid inheritance?

A

genetic diagrams involving a single gene, it can show dominant and recessive inheritance e.g. tall + short pea plants, tall allele dominant to dwarf

102
Q

what else can be shown?

A

codominance inheritance e.g. in white + red salvia plants produce pink

103
Q

pea plant experiment?

A

cross breeding pure tall and dwarf produces tall in first generation, crossing of F1 always produced 3 tall plants to 1 dwarf

104
Q

what are the rules of genetic diagrams?

A

identify - tall plant is dominant
give alleles symbols tall= T dwarf t
always letters that look different.

105
Q

what are the 3 blood groups?

A

Ia Ia and Ib are codominant
Ib
Io

106
Q

what is sex linkage?

A

refers to genes carried on sex chromosomes

X chromosome bigger than Y, X carries more genes

107
Q

where is sex linkage found?

A

on X chromosomes not on Y it can have a recessive allele which leads to a particular condition, condition is more likely to occur in women

108
Q

what is haemophilia?

A

if one of the genes has a recessive allele that causes the condition then it is more common in males

109
Q

symptoms of haemophilia?

A

bleeding into joints can be disabling

Biology (9 decks)

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