Brainscape's Knowledge GenomeTM

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


See full index

human biology > Cell biology > Flashcards

Cell biology Flashcards

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

are somatic cells diploid or haploid?

A

diploid and contain two sets of homologous chromosomes

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

what are somatic cells?

A

they are all body cells which arent involved in reproduction

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

what are germline cells?

A

they are reproductive cells

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

what can germline cells divide by?

A

divide by meiosis (to produce haploid gametes e.g sperm/egg cell) or mitosis (to produce more germline cells)

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

what do somatic cells divide by?

A

mitosis

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

haploid cells have how many chromosomes (in a human?)

A

23 single chromosomes

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

what is cellular differentiation?

A

this is the process by which a cell expresses certain genes to produce protein characteristic for that type of cell, this allows a cell to carry out specialised functions

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

what are the two types of stem cells in mammals?

A

embryonic and tissue stem cells

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

what are stem cells?

A

they are unspecialised somatic cells that can divide to make copies of themselves (self-renew) and to make cells that differentiate into specialised cells of one or more types

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

what are the two stages of gene expression?

A

transcription

translation

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

medical uses of PCR?

A

diagnosing disease

estimate the risk of disease onset

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

forensic uses of PCR?

A

to amplify DNA samples from crime scenes

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

What is used to confirm a paternity dispute after PCR

A

gel electrophoresis can be used to confirm

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

what does PCR stand for?

A

polymerase chain reaction

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

steps of PCR?

A

DNA is heated between 92-98 degrees to separate the DNA strands

it is then cooled to between 50-65 degrees to allow primers to bind target sequences

it is then heated to between 70 and 80 degrees for heat tolerant DNA polymerase to replicate the region of DNA

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

what is gene expression?

A

is the process by which specific genes are activated to produce a required protein

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

are all the genes in a cell expressed?

A

only a fraction of genes in a cell are expressed

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

what are the 3 types of RNA needed in transcription and translation

A

mRNA tRNA and rRNA

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

what does mRNA do?

A

mRNA is also known as messenger RNA and is used to carry a copy of the DNA code from the nucleus to the ribosome. type of RNA that makes up ribosomes

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

function of mRNA?

A

mRNA is transcribed from DNA in the nucleus and translated into proteins by ribosomes in the cytoplasm

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

what is codon (mRNA)

A

each triplet of bases on the mRNA molecule is called a codon and codes for a specific amino acid

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

why does tRNA fold?

A

tRNA folds due to complimentary base pairing

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

DNA replication

A

process by which a cell makes an identical copy of its DNA

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

when does DNA replication happen?

A

at the start of cell division

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

what does DNA replication ensure?

A

DNA replication ensures that each daughter cell inherits an identical copy of DNA

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

Requirements - what do you need to make a new copy of DNA?

A
  • Original DNA template
  • Free DNA nucleotides
  • DNA polymerase - enzyme that adds new nucleotides to a growing strand of DNA
  • Primers - short strands of nucleotides that bind to the 3’ end allowing DNA polymerase to add free nucleotides.
  • ATP (from respiration)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is a primer?

A

primers are short complimentary strands of nucleotides that allow DNA polymerase to bind.

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

which way does DNA polymerase add nucleotides in?

A

3’-5’ direction

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

what is the effect of the way that DNA polymerase add nucleotides have?

A

the lagging strand, primers are added one by one into the replication fork as it widens.

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

what is the DNA fragments joined by?

A

DNA ligase to form a complete complementary strand

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

where does the energy in DNA replication come from?

A

the process requires energy, which is supplied by ATP produced by the cells respiration.

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

what is a gene?

A

Gene = unit of genetic code (section of DNA that codes for a specific protein)

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

how many genes in a cell are expressed at once?

A

Only a fraction of the genes in a cell are expressed at one time.

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

what is RNA?

A

Ribonucleic acid.

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

qualities of DNA

A

2 stranded
Deoxyribose sugar
Adenine - Thymine
Cytosine - Guanine

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

qualities of RNA

A

Single stranded
Ribose sugar
Adenine - Uracil
Cytosine - Guanine

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

mRNA function?

A

carries complementary copy of the genetic code from DNA (nucleus) to ribosomes in the cytoplasm

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

what type of structure does mRNA have?

A

linear

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

rRNA function?

A

Combined with proteins to make up the structure of a ribosome.

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

where does transcription happen?

A

nucleas

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

where does translation happen?

A

at ribosome (in the cytoplasm)

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

stages of transcription

A

Helicasemoves along the DNA unwinding the strand.
Hydrogen bonds between base pairs break which allows the unzipping of the double helix.
As helicase breaks the bonds, it synthesises a primary transcript of mRNA using RNA nucleotides. These form hydrogen bonds with the exposed DNA strand by complementary base pairing.
The primary transcript of mRNA is processed to produce a mature transcript of mRNA.
The mature mRNA transcript is now ready to leave the nucleus and travel to the ribosome.

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

alternative splicing

A

A transcript from a single gene can be alternatively spliced by treating certain introns as exons
a cell can use one gene to produce different proteins depending on age, metabolic needs, health etc.

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

enzymes

A

• Optimums - conditions at which an enzyme is most active (temperature/ pH)
• Biological Catalysts - speed up reactions in cells
• Protein
• They have active sites - the region where the substrate (the substance that the enzyme acts on) attaches and the reactions takes place.
• Products - what an enzyme catalysed reaction produces.
• Specific - one enzyme fits one substrate. (lock and key)
Denatured - active site’s shape is changed by extremes of temperature and pH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what can cause an absence of a functional enzyme?

A

A mutation may cause the absence of a functional enzyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what are enzymes and how do they work?

A

Enzymes are biological catalysts that speed up rate of chemical reactions by lowering the activation energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Activation energy

A

Energy required to initiate a reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

mutations

A

mutations are random, spontaneous, rare changes to DNA sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what is DNA?

A

a substance that encodes the genetic information of heredity in a chemical language

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what shape is DNA?

A

DNA is a very long double stranded molecule in the shape of a double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

amino acid

A

unit of polypeptide structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

anticodon

A

sequence of 3 bases on tRNA that codes of specific amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

codon

A

sequence of three bases on mRNA that codes for a specific amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

exon

A

coding sequence of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

tRNA attachment site

A

site on tRNA molecule to which a specific amnio acid binds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

interactions

A

chemical attractions and bonding such as hydrogen bonds between amino acids giving proteins their 3D shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

intron

A

non-coding sequence of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

mature transcript

A

RNA transcript which has been spliced and processed ready for transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

peptide bond

A

strong chemical link between amino acids in the structure of a polypeptide

60
Q

phenotype

A

a cells physical and chemical state and is determined by the proteins it produces along with environmental factors that can influence the cell

61
Q

polypeptide

A

short strand of amino acids

62
Q

primary transcript

A

molecule made when DNA is transcribed

63
Q

ribose

A

sugar that forms part of RNA nucleotide

64
Q

RNA splicing

A

joining of exons following the removal of introns from a primary transcript

65
Q

start codon

A

first codon of mRNA transcript translated by a ribosome

66
Q

stop codon

A

codon within mRNA that signals termination of translation into proteins

67
Q

what can mutations result in?

A

absence of protein production or production of an altered protein

68
Q

what does single gene mutation involve?

A

single gene mutation involves the alteration of a DNA nucleotide sequence as a result of substation , insertion or deletion of nucleotides.

69
Q

example of substitution

A

replacing adenosine with guanine

70
Q

insertion example

A

adding in another guanine

71
Q

deletion example

A

deleting cytosine

72
Q

chromosome

A

rod-like structure that contains the genetic material of an organism encoded into DNA

73
Q

deletion of genes

A

chromosome mutation in which a sequence of genes is lost from a chromosome

74
Q

deletion of nucleotides

A

chromosome mutation in which involves removing a nucelotide from a sequence

75
Q

translocation

A

chromosome mutation in which part of a chromosome becomes attached to another

76
Q

substitution

A

single gene mutation in which one nucleotide is replaced by another

77
Q

protein

A

large molecule made up of chains of amino acid (polypeptides) linked by peptide bonds

78
Q

stages of DNA replication

A

stage 1: DNA unwinds and unzips (hydrogen bonds between bases are broken)

stage 2: DNA polymerase can only add nucleotides in a 3’ to 5’ direction and therefore adds free nucleotides to the 3’ end which uses complimentary base pairing.
- the leading strand is replicated continuously
- lagging strand is replicated in fragments nucleotides cannot be added to the phosphate (5’) end because DNA polymerase can only add DNA nucleotides in a 5’ to 3’ direction
the lagging strand is therefore synthesised in fragments
the fragments are then sealed together by an enzyme called ligase

stage 3: 2 new strands twist to form a double helix

79
Q

what do RNA nucleotides contain?

A

RNA nucleotides contain a ribose sugar, a phosphate and a base

80
Q

where is tRNA found?

A

cytoplasm

81
Q

why is tRNA folded on itself?

A

due to hydrogen bonds forming between bases

82
Q

what are tRNA anticodons complimentary with?

A

mRNA codons

83
Q

what is the job of tRNA

A

tRNA pick up specific aminio acids (with its attachment site) in the cytoplasm and carry them to the ribosome

84
Q

what does the genetic code translate into and what translates it?

A

mRNA codons and tRNA anticodons translate the genetic code into the correct sequence of amino acids to make a protein

85
Q

where are introns found?

A

between the exons

86
Q

what is cut out from the primary transcript during transcription?

A

introns are cut out and removed from the primary transcript

87
Q

what happens to exons during transcription?

A

exons are spliced together (RNA splicing) to form mRNA with a continuous sequence exons (this is called the mature transcript of RNA)

88
Q

where does the mature transcript of mRNA move from?

A

it moves from the nucleus through the cytoplasm and to a ribosome

89
Q

when does translation begin and end?

A

translation begins at a start codon and ends at a stop codon

90
Q

stages of translation

A

the mRNA molecule (with transcript) travels through the cytoplasm and attaches to the ribosome.
tRNA molecules transport specific amino acids to the ribosome.

Each mRNA codon codes for a specific amino acid.

The first codon of an mRNA molecule is a start codon. This signals the beginning of translation.

The anti-codons and codons match up and form complementary base pairs.
Peptide bonds form between the adjacent amino acids to form the polypeptide (protein).

Used tRNA molecules exit the ribosome and collect another specific amino acid.
The last codon of an mRNA molecule is a stop codon which signals the end of translation.

91
Q

what are amino acids linked by?

A

they are linked by peptide bonds to form poly peptides

92
Q

why do polypeptide chains fold?

A

they fold to form 3d shape of a protein which is caused by hydrogen bonds and other interactions between individual amino acids

93
Q

what is a genetic disorder?

A

a genetic disorder is a condition or disease that is directly related to the individuals genotype

94
Q

what determines the structure and function of proteins?

A

the sequence of amino acids determines the structure and function of the protein

95
Q

do mutation rates vary?

A

mutation rates vary from gene to gene and species to species

96
Q

what are mutations increased by?

A

Mutations can be increased by mutagenic agents (e.g. mustard gas) and various types of radiation (X-Rays, UV light, Gamma Rays)

97
Q

Missense

A

result in one amino acid being changed for another, may result in a non-functional protein or it could have little effect
Example: Sickle-cell disease, PKU

98
Q

Nonsense

A

result in a premature stop codon being produced so no amino acid is made and translation stops, produces a shorter protein
Example: Duchenne muscular dystrophy (DMD)

99
Q

Splice-Site

A

result in some introns being retained and/or some exons not being included in the mature transcript
Example: Beta Thalassemia

100
Q

what is the genome of an organism?

A

total genetic material present in an organism

101
Q

what is the genome made up of?

A

The genome is made up of genes and other DNA sequences that do not code for proteins

102
Q

what does genome sequencing involve?

A

Genomic sequencing involves determining the sequence of nucleotide bases along the DNA

103
Q

what can genome sequencing be used for?

A

Genomic sequencing can be used to find out about individual genes and the entire genome

104
Q

bioinformatics

A

Bioinformatics is the name given to the fusion of molecular biology, statistical analysis and computer technology to map and analyse DNA sequences

105
Q

what can be used to identify base sequence?

A

computer programs can be used to identify base sequences by looking for sequences similar to known genes

106
Q

what can bioinformatics be used for?

A

Bioinformatics can be used to investigate evolutionary biology, inheritance and personalised medicine

107
Q

what is a personal genome sequence?

A

A personal genome sequence is a complete set of the person’s DNA bases

108
Q

what is personal medicine based off of?

A

Personalised medicine is based on an individual’s genome

109
Q

what is pharmacogenetics?

A

Pharmacogenetics is the study of the effects of pharmaceutical drugs on the genetically diverse members of the human population it means that medical treatment could be customised to suit an individuals’ exact metabolic requirements using information gained from genomics e.g. the most suitable drug and correct dosage

110
Q

cancer cells

A
  • cancer cells divide excessively to produce a mass of abnormal cells called a tumor
  • tumour cells do not respond to regulatory signals which results in a mass of abnormal cells
  • some of these cells may fail to attach to each other, spreading through the body where they form secondary tumours
  • metastasis is the spread of cancer from its primary to other places in the body
111
Q

what can be separated by gel electrophoresis?

A

macromolecules such as fragments of DNA from a source can be separated by gel electrophoresis

112
Q

sequence data

A

information concerning amino acid or nucleotide base sequences of gene or entire human genome

113
Q

non-coding

A

sequences of DNA that do not code for proteins including those that are transcribed but not translated and sequences involved in gene regulation

114
Q

what is a result of alternative RNA splicing?

A

different proteins can be expressed from one gene as a result of alternative RNA splicing

115
Q

what is an example of a mutation?

A

sickle cell disease

116
Q

what is a protein?

A

one or more polypeptide chain

117
Q

what are fragments?

A

replicated sequences of the lagging strand which are later joined by ligase

118
Q

antiparallel

A

paralel strands in DNA that run in opposite directions in terms of chemical polarity

119
Q

what is gel electrophoresis?

A

method of for separation of macromolecules such as fragments of DNA based on their size and electrical charge.

120
Q

what is one way that the expression of a single gene can result in production of different proteins?

A

alternative RNA splicing

121
Q

frame-shift

A

frame-shift causes all of the codons and all the amino acids after the mutation to be changed. this has a major effect on the structure of the protein that is produced

122
Q

what is the sugar found in dna?

A

deoxyribose sugar

123
Q

what sugar is found in rna?

A

ribose sugar

124
Q

what do nucleotides link by deoxyribose to phosphates form?

A

sugar phosphate backbone

125
Q

what is dna polymerase?

A

enzyme that adds new nucleotides to a growing strand of dna

126
Q

what is PCR?

A

laboratory technique for amplifying specific targer sequences of DNA

127
Q

what is thermocycling?

A

cycles of heating and cooling

128
Q

requirements for PCR

A
  • DNA / original strand
  • complementary primers (to start synthesis)
  • heat tolerant DNA polymerase (adds nucleotides and is not denatured by high temperatures)
  • supply of nucleotides
129
Q

what are non-medical uses of PCR?

A
  • used to settle paternity disputes

- sample of DNA from crime scenes

130
Q

what is the DNA produced in PCR used for after?

A

The DNA produced in PCR is then used in gel electrophoresis

131
Q

steps of gel electrophoresis?

A

fragments are stained then placed in a well cut into block of agarose gel. an electrical current is then passed through the gel causing the fragments to move in the gel.

132
Q

in gel electrophoresis, what fragments move faster?

A

shorter fragments move faster and pass farther than longer ones.

133
Q

what is the final position of the fragments indicated by in gel electrophoresis?

A

the final position of the fragmenrs are indicated by bands of strain in the gel known as a ladder or profile.

134
Q

what are base pairs held together by?

A

weak hydrogen bonds

135
Q

what does the base sequence of DNA form?

A

the genetic code

136
Q

which type of stem cell is pluripotent and why?

A

embryonic stem cells because of how they can differentiate into all types of cells that can make up an individual

137
Q

which type of stem cell is multipotent and why?

A

tissue stem cells because they can differentiate into all types of cells found in a particular tissue type

138
Q

why are embryonic stem cells controversial?

A

this is because they involves the destruction of an embryo.

139
Q

diploid

A

refers to a cell having two matching sets of chromosomes

140
Q

what is a secondary tumour?

A

cancer formed from cells transported from a primary tumour

141
Q

where does genetic information come from?

A

genetic information is inherited

142
Q

what is a fragment in DNA replication?

A

replicated sequences of the lagging strand which are later joined by ligase

143
Q

what is the benefit of RNA splicing?

A

The benefit of RNA splicing is that one gene can produce many different proteins as a result of what segments are treated as introns and exons.

144
Q

what are single gene mutations a result of?

A

a change to a single gene nucleotide

145
Q

what are the three types of single gene mutations?

A

the substitution of one nucleotide with another
the insertion of one or more nucleotides into a DNA sequence
the deletion of one or more nucleotides from a sequence

146
Q

example of therapeutic use of stem cells?

A

skin graphs

human biology (6 decks)

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