Molecular Techniques Flashcards Preview

Medical Cell Biology And Genetics > Molecular Techniques > Flashcards

Flashcards in Molecular Techniques Deck (49)
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1
Q

What produce endonucleases

A

Bacteria

2
Q

What do restriction enzymes do

A

Recognise and degrade foreign DNA

3
Q

Which electrode do DNA fragments travel toward in electrophoresis and why

A

Positive as DNA is negatively charged

4
Q

What sized fragments travel the furthest

A

Small

5
Q

What does DNA gel electrophoresis do

A

Separate fragment based on size

6
Q

How are genes cloned

A

Isolate specific gene with restriction enzymes and insert into plasmid vector to place into bacteria to replicate naturally

7
Q

What are plasmids

A

Small circular DNA

8
Q

Give an example of when human genes are cloned

A

To make human insulin

9
Q

What enzyme concerts mRNA into cDNA

A

Reverse transcriptase

10
Q

What disease is currently being treated using gene therapy

A

Cystic fibrosis

11
Q

What enzyme is used in PCR and why

A

Taq Polymerase as it can work at higher temperatures

12
Q

What is the first step in PCR

A

Heat strands to 95 degrees to denature DNA to give single strands

13
Q

What is the second step of PCR

A

Cool DNA to 55 degrees to allow DNA primers to bind

14
Q

What is the final step of PCR

A

Heat to 72 degrees to allows taq Polymerase to bind and add nucleotides from the 3’ end.

15
Q

Why is PCR used

A

Look for mutations, to see if there’s a loss or gain of restriction fragments or to see size of product

16
Q

Why can you use PCR to determine if someone has sickle cell anaemia

A

In sickle cell the mutation changes a restriction site and so this site will not be cut like it would in normal DNA

17
Q

What does PCR result in

A

Lots of copies of a specific piece of DNA

18
Q

What is protein gel electrophoresis

A

Separation of proteins

19
Q

What different types of protein electrophoresis are there?

A

SDS page, isoelectric focussing and 2D page

20
Q

What is SDS page

A

When proteins are denatured, given a negative charge and separate due to size as they migrate to the positive electrode

21
Q

What is 2D page separation

A

Separation of proteins based on size and charge

22
Q

What is isoelectric focussing

A

Separation of proteins based on charge. Protein migrate until they reach a pH equal to their pI

23
Q

What is proteomics

A

Protein identification

24
Q

How do you carry out proteomics

A

Digest protein, perform mass spectrometers and identify protein based on peptide sizes

25
Q

What Techniques uses antibodies instead of DNA hybridisation

A

Western blotting

26
Q

What is ELISA

A

A technique to detect protein concentration in a mixture by using antibodies to bind to the protein

27
Q

What is an enzyme assay

A

A technique used to measure enzyme activity by measuring appearance of product or disappearance of substrate

28
Q

The concentration of which enzyme increases during a heart attack

A

Creatine Kinase

29
Q

What are monoclonal antibodies

A

Antibodies that can bind to 1 epitope/protein only

30
Q

What are polyclonal antibodies

A

Antibodies that can bind to multiple epitope in the same antigen

31
Q

Outline DNA hybridisation

A

When a double stranded DNA is heated and denatured and then labelled, complementary markers are allowed to anneal to the single strands.

32
Q

Outline southern blotting

A

Separate DNA using electrophoresis then transfer to membrane, denature and hybridise with fluorescent
probes to visualise DNA fragments

33
Q

What is northern blotting

A

Uses DNA in a method similar to northern blotting but detects RNA so tells you gene expression

34
Q

What is western blotting

A

Using antibodies to visualise proteins

35
Q

What produces DNA probes

A

Oligonucleotide synthesiser

36
Q

What are ddNTPs

A

DNA nucleotides that have 3 phosphate groups and no OH group

37
Q

What happens when ddNTPs are incorporated into the growing chains

A

They stop the chain from growing as the lack of OH stops phosphodiester bonds being made

38
Q

What technique uses ddNTPs

A

DNA sequencing

39
Q

What can you do with micro arrays

A

Investigate many genes at one time

40
Q

Outline micro arrays

A

You compare gene expression from a healthy and diseased patient by mixing samples with hybridisation probes and look at colour to determine expression

41
Q

What regions are compared during DNA fingerprinting

A

Minisatellites

42
Q

What are minisatellites

A

Non coding regions of DNA

43
Q

Why are minisatellites compared for DNA profiling

A

Everyone has different amount of different minisatellites

44
Q

What is karyotyping

A

Displaying metaphase chromosomes

45
Q

What is FISH

A

Making probe which are specific for a whole chromosome or gene so that these areas can be visualised

46
Q

What ethical issues are there with investigating the genome

A

Potential for terminating babies, can’t identify all mutations, can lead to future personal consequences (e.g with genetic diseases you may or may not have children )

47
Q

What are reasons for testing someone’s genome

A

To diagnose conditions, for prenatal screening for pregnancy decision and to see if someone’s a carrier

48
Q

What is a primer

A

Short section of DNA that acts as a starting point for DNA synthesis as Polymerase binds here

49
Q

What is reverse transcriptase PCR

A

Starting with an mRNA strand, producing the cDNA strand and amplifying it