Brainscape's Knowledge GenomeTM

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


See full index

ESA1 Revison > Molecules, Genes and Disease > Flashcards

Molecules, Genes and Disease Flashcards

1
Q

What is the function of the mitochondria?

A

ATP synthesis

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

What are the functions of the plasma membrane?

A

Transport of ions and small molecules

Cell morphology and movement

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

What are the functions of the cytoplasm?

A

Metabolism of carbohydrates, amino acids and nucleotides

Fatty acid synthesis

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

What are the functions of the nucleus?

A

DNA synthesis and repair
RNA synthesis and processing
Ribosome assembly

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

What are the functions of the Golgi?

A

Export of proteins

Detox reactions

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

What is pK

A

How readily an acid will dissociate, and therefore how strong it is

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

How can amino acids be classified?

A

Aliphatic or aromatic

polar, uncharged, non polar, negatively charged or positively charged

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

What is the isoelectric point?

A

The pH at which a molecule has no overall charge

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

Why does haemoglobin have a sigmoidal affinity curve for oxygen?

A

Because it can exist in a tense or relaxed state. When one oxygen molecule brings it changes from the low affinity T state to the high affinity R state. This makes it more sensitive to slight changes in partial pressure.

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

What are the functions of the smooth and rough ER?

A

Protein synthesis and transport
Membrane synthesis
Lipid and steroid synthesis
Detox reactions

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

Describe the Bohr effect

A

Presence of protons and carbon dioxide in the blood make it more acidic, reducing the O2 affinity of haemoglobin, causing increased oxygen deposition in the more metabolically active tissues.

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

What affect does BPG have on haemoglobin and what does BPG stand for?

A

Reduces O2 affinity, shifts association curve to the right, promotes oxygen deposition in the tissue.
2’3-bisphosphoglycerate

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

What affect does CO have on haemoglobin?

A

Binds irreversibly, reducing the amount of haemoglobin available for oxygen transport.

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

What is the mutation and a.a. Change in sickle cell anaemia?

A

A to T point mutation

Glutamic acid to valine substitution

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

What is the consequence of the sickle cell mutation?

A

Valine is hydrophobic, so creates a hydrophobic ‘sticky’ region in the beta chain, when in T state the haemoglobin polymerises causing RBCs to adopt a sickle shape. Can occlude small vessels.

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

What factors promote sickle cell crisis?

A

Anything that reduces O2 concentration e.g. Smoking, obesity.

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

What are the complications of sickle cell anaemia?

A

Haemolytic anaemia

Jaundiced due to excess bilirubin due to increased RBC turnover

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

What are the two types of thalassemia, and why are they different?

A

Alpha - due to decreased or absent alpha haemoglobin chains, appears before birth.
Beta - due to decreased or absent beta haemoglobin chains, appears after birth because fetal haemoglobin contains alpha and theta chains.

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

Define Vmax

A

Maximal rate when all enzyme sites are saturated with substrate

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

Define Km

A

Substrate concentration that gives half the maximal rate of reaction

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

What do the intercepts on the lineweaver-burk plot show?

A

X axis - negative reciprocal of Km

Y axis - reciprocal of Vmax

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

What kind of inhibitors bind covalently and destroy enzyme function?

A

Irreversible

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

What are the two types of reversible inhibitors?

A

Competitive -bind to active site, affect kM not Vmax. Can be overcome by increasing substrate concentration.
Non competitive - bind away from active site, affect Vmax not Km. can’t be overcome by increasing substrate concentration.

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

What is allosteric control?

A

Multi subunit enzymes which have multiple binding sites, either for the binding of inhibitors or activators, or for one substrate to bind to, promoting the binding of a second substrate.

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

Give an example of an allosteric enzyme and its control

A

Phosphofructokinase is activated by AMP and inhibited by ATP

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

Name two mechanisms of regulation of enzymes and give examples of them - not including allosteric control.

A

Covalent modification e.g. Phosphorylation
Proteolytic activation - inactive enzyme zymogen has protein cleaved to produce the active form. E.g. Trypsinogen and trypsin.

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

What is the benefit of enzyme cascades?

A

Allows amplification of a signal very rapidly

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

Describe the clotting cascade - 5 points.

A

Inactive zymogens of tissue factors are present in the blood at low concentrations
Damage to endothelium creates a cascade of activation resulting in a insoluble fibrin clot
Factors with gla domains bind to endothelial cells and allow rapid activation of downstream effector molecules.
Activated thrombin feedback to enhance the conversion of factors V, VIII, and XI to activated forms
Clotting is stopped by the removal of activated proteins, proteolyric digestion and the binding of inhibitor molecules.

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

What are the purine and pyramiding RNA nucleotide bases?

A

A and G are purine

C and U are pyramidine

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

What are the purine and pyramidine DNA nucleotide bases?

A

A and G purine

C and T pyramidine

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

In which direction is it conventional to write base sequences?

A

5 prime to 3 prime

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

Which enzyme unraveled the DNA helix?

A

DNA helicase

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

What enzyme catalysed the condensation reaction between DNA nucleotides?

A

DNA polymerase

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

Which direction does the nucleotide chain grow in DNA replication?

A

5 prime to 3 prime

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

What is different about the synthesis of the leading and lagging strand?

A

Leading strand is synthesised continually

Lagging strand is synthesised in Okazaki fragments

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

What enzyme joins the Okazaki fragments?

A

DNA ligase

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

What happens in stage G1 of the cell cycle?

A

Cell prepares for DNA replication, cellular contents duplicated

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

What happens during stage s of the cell cycle?

A

DNA replication

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

What happens during stage g2 of the cell cycle?

A

Checks and repairs duplicated DNA

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

Define gene

A

A length of DNA which codes for a protein or RNA

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

Define allele

A

Specific version of a gene

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

What are the three main patterns of inheritance?

A

Autosomal dominant
Autosomal recessive
X linked

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

Define codominance

A

When both alleles are expressed in the heterozygote, e.g. AB blood type

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

Define complementation

A

When more than one gene is responsible for the phenotype

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

Define co-inheritance

A

Genes on the same chromosome tend to be inherited together, they after linked. The closer together their locus the less likely they are to be separated by crossing over.

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

What are the tree stages of transcription and translation ?

A

Initiation
Elongation
Termination

47
Q

Describe the initiation stage of transcription

A

Promoter region recognition

Binding of transcription factors and RNA polymerase to the TATA box

48
Q

Describe the process of elongation in transcription

A

RNA is transcribed, the DNA is read 3 prime to 5 prime

49
Q

Describe the process of termination in transcriptioN

A

sequence dependent termination of RNA chain growth

50
Q

Describe the process initiation in translation

A

AUG codon recognised and ribosomal sub units bind around it to form a functional ribosome

51
Q

Describe the process of elongation in translation

A

tRNA brings amino acids, ribosome catalysts the condensation reaction between them. mRNA is read 5’ to 3’ and amino acids run N to C

52
Q

Describe the process of termination in translation

A

Stop codon recognition and dissociation of the ribosome

53
Q

In what three ways is RNA processed?

A

Capping of 5’ end
Tailing of 3’ end with poly A tail
Splicing of introns

54
Q

What is a codon?

A

Three base pairs that code for an amino acid

55
Q

Why is DNA code said to be degenerate?

A

There are more 3 letter combinations than there are amino acids, so there are several ways of coding for each amino acid.

56
Q

Which type of RNA exits in 1000s of forms with just a few copies of each form?

A

mRNA

57
Q

Which type of RNA exists in many types with many copies of each type?

A

tRNA

58
Q

Which type of RNA exists in just a few types but there are 1000s of copies of each type?

A

rRNA

59
Q

In what 5 ways is protein synthesis different in bacteria?

A 
Simpler promoter region
Coupled transcription and translation 
Shortlived, non processed mRNA
70s ribosomes 
Different RNA polymerase (can be a target for drugs)
60
Q

Describe constitutive secretion and give an example of a protein produced this way

A

It is a continuous process
Proteins are packaged into vesicles and released continuously by exocytosis
E.g. Collagen, serum albumin

61
Q

Describe regulated secretion and give an example of a protein secreted this way

A

Protein is packaged into vesicles but only released in response to a signal
E.g. Insulin

62
Q

Describe the secretory pathway (8 points)

A

mRNA recognised by the free ribosome
N-terminal signal sequence produced
SRP (signal recognition protein) recognises sequence
SRP directs ribosome to the ER membrane where it attaches to a peptide translocation complex
SRP dissociates
Protein synthesis continues, protein is fed into ER lumen
Signal sequence removed by signal peptidase
Ribosome dissociates and is recycled

63
Q

What organelle carries out n-linked glycosylation?

A

ER

64
Q

What organelle carries out the majority of o-linked glycosylation?

A

The Golgi

65
Q

What is proteolytic processing?

A

Removal of a signal peptide to convert inactive protein to an active one

66
Q

Describe the formation of insulin

A

Signal sequence removed from preproinsulin
Disulphides bridges form on proinsulin
C peptide is remove forming insulin

67
Q

Describe how collagen is made in the ER (3 points)

A

Protein synthesised and signal peptide cleaved
Protein is modified by hydroxylation and addition of n-linked oligiosaccharides and galactose
Disulphides bridges and triple helix of procollagen form

68
Q

Describe how collagen is modified by the Golgi

A

Glucose is added to o-linked galactose

69
Q

How does collagen go from the Golgi to a fibrin strand?

A

Secreted in vesicles into extra cellular space
N and c terminal properties are cleaved
Molecules associate laterally into fibrils
Fibrils aggregate to form fibre

70
Q

Describe gene cloning (3 points)

A

Plasmid cut using restriction enzymes and gene of interest is added to create a recombinant plasmid
Plasmid is introduced to bacterium
Bacteria multiply

71
Q

Describe restriction analysis (2 points)

A

Restriction enzymes are bacterial enzymes which recognise specific DNA sequences know as restriction sites and cut the DNA at that point
This creates sticky ends which can be joined using DNA ligase

72
Q

Describe DNA sequencing (2 points)

A

Fluorescent/radioactively stained ddNTPs and dNTPs are added to a mixture containing a DNA template strand with polymerase to create many strands of varying length
The fragments of different sizes can be separated using electrophoresis and the sequence determined

73
Q

Describe gel electrophoresis

A

Solution with DNA fragments is placed in well at negative electrode
Negatively charged DNA molecules are attracted to the positive electrode
Larger fragments are slower so do not travel as far
Known DNA lengths are used for reference

74
Q

How does PCR work and what is it used for?

A 
Uses thermal stable Taq polymerase to amplify DNA fragments 
1- denaturation at 94-96 degrees c 
2- renaturation at 50-65 degrees c
3- DNA synthesis at 75-80 degrees c 
This cycle is repeated many times
75
Q

Describe SDS page

A

The detergent SDS is adds to a protein sample. This denatures tertiary structure and gives proteins a negative charge, allowing them to be separated by molecular weight using gel electrophoresis

76
Q

Describe isoelectric processing

A

Proteins placed in gel with pH gradient

Will migrate to a pH which matches their isoelectric point

77
Q

Describe 2D page

A

After isoelectric processing the gel is turned 90 degrees allowing proteins with the same pI to separate into different weights

78
Q

What can be measure d using enzyme assays? Give an example of the clinical relevance of this.

A

Enzyme activity levels
An indication of whether an enzyme is present at normal levels
Test for enzymes that shouldn’t be there, e.g. Alanine transaminase shouldn’t be in the blood - indicator of liver damage

79
Q

Under what conditions are enzyme assays performed?

A

Optimal pH, temperature and ionic strength

Including appropriate ions and cofactors

80
Q

Describe western blotting, what technique usually precedes it?

A

Follows SDS page

Proteins transferred to nitrocellulose membrane and identified by conjugating with labelled antibodies

81
Q

How are immunoassay carried out and what can they detect?

A

Antibody is immobilised on a slid support
Solution to be assayed is applied
Second antibody conjugated to an enzyme binds to the antibody-antigen complex
Binding of the second antibody is measured by assaying for the enzyme
Can detect protein concentration

82
Q

Describe the process of southern blotting?

A

Fragments from electrophoresis are transferred using nylon. These fragments can then be hybridised with a gene probe to look for specific DNA fragments

83
Q

What is southern blotting used for?

A

Mark unlabelled DNA from gel electrophoresis
Investigate gene structure e.g. Large deletions and duplications
Investigate gene expansions
Investigate variation, e.g. DNA fingerprints

84
Q

What molecule is identified using northern blotting?

A

RNA

85
Q

How can PCR be used for allele specific testing?

A

Use primers specific to the allele of interest to amplify specific allele

86
Q

How can restriction enzymes be use for allele specific testing?

A

Use restriction enzymes with restricting sites near or within the allele - analyse the size of the fragments produced

87
Q

How can DNA hybridisation be used for allele specific testing?

A

Use a DNA probe which is complementary to either the wild type or the mutated allele, see what binds.

88
Q

What is a silent mutation?

A

A mutation which does not alter the amino acid sequence

89
Q

What is a missense mutation?

A

Replaces one amino acid with another

90
Q

What is a nonsense mutation?

A

Replaces one amino acid with a stop codon

91
Q

What is a frame shift mutation?

A

Insertion or deletion which isn’t in multiples of three, so alters the whole amino acid sequence.

92
Q

What is a spontaneous mutation?

A

A mutation that occurs randomly

93
Q

What is an induced mutation?

A

A mutation that is cause by a mutagen, e.g. UV light

94
Q

What is mismatch repair?

A

After replication any incorrectly inserted nucleotides are recognised and replaced with the correct base

95
Q

What is excision repair? What are the two types?

A

Repair single stranded DNA damage caused by external damage. Base or nucleotide excision repair.

96
Q

What happens if DNA is damaged to the point where apoptosis doesn’t occur or they grow uncontrollably?

A

Cells become cancerous

97
Q

What is a oncogene?

A

Genes that control cell division in cancerous cells. When healthy they are known as protoncogenes

98
Q

What is array comparative genome hybridisation used for?

A

Screen for submicroscopic chromosome deletions with unknown locus

99
Q

How is array comparative genome hybridisation carried out?

A

An array of DNA probes covering the entire genome are applied to the surface of a solid matrix
Patient DNA is labelled red and control DNA is labelled green
Equal amounts of patient and control DNA is hybridised to the probe array
Green areas show deletions

100
Q

What ethical issues are associated with gene technology? (3 examples)

A

Insurance companies could charge people differently for life insurance
People could ask for abortions because they don’t want a girl/ginger/I’ll e.t.c child
Getting tested for a dominant condition - you’re family might rather not know

101
Q

What constitutes chromatin? 4 things

A

DNA
RNA
Non-histone proteins
Histones

102
Q

What is the difference between euchromatin and heterochromatin?

A

Euchromatin is actively transcribed - Pale in colour

Heterochromatin is tightly packed, dense and darker in colour as it is not actively transcribed

103
Q

How many chromosomes in humans?

A

23 pairs - 46 chromosomes

104
Q

Give 4 examples of numerical chromosome abnormalities

A

Polyploidy - a complete extra set of chromosomes e.g. Triplody
Aneuploidy - a number of chromosomes that isn’t a multiple of the haploid number
Monosomy - a loss of one chromosome
Trisomy- a gain of one chromosome

105
Q

What are structural chromosome abnormalities?

A

Physical changes to one or more chromosomes

106
Q

What is the difference between balanced and imbalanced structural chromosome abnormalities?

A

Balanced- doesn’t result in missing or extra genetic information
Imbalanced- does result in missing it extra genetic information

107
Q

What types of single chromosome mutation are there? Hint: 5

A 
Deletion
Duplication 
Inversion 
Ring chromosome due to lost telomere
Isochromosome - creation of two non identical chromosomes
108
Q

What type of mutations occur between 2 chromosomes? 3 things.

A

Inversion - rearrangement to a non homologous chromosome
Reciprocal translocation - an exchange of genetic information between 2 non homologous chromosomes
Robertsonian translocation- rearrangement of genetic material between two chromosomes where 2 long arms combine and 2 short arms are lost.

109
Q

What is a karyotype?

A

A picture set of metaphase chromosomes organised systematically into pairs.

110
Q

How would you describe a woman with 46 chromosomes who has a missing segment of the p arm on chromosome 5?

A

46, XX 5p-

111
Q

How would you describe a man with triploidy who also has some extra genetic information on the q arm of 10th chromosome?

A

69 XY 10q+

112
Q

What 3 prenatal screening results may mean the patient requires karyotype screening?

A

Down’s syndrome
Family history of chromosome abnormality
Abnormal fetal ultrasound

113
Q

What other 6 problems may lead to karyotype referral?

A 
Malformations at birth 
Mental retardation at birth 
Abnormal sexual development
Infertility 
Recurrent fetal loss
Leukaemia
114
Q

Describe FISH

A

DNA probes hybridised to target DNA in sample
Fluorescent probe shows locus of target DNA
Can be used to identify whole parts of chromosomes

ESA1 Revison (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions