Controlling Gene Expression

Question 1

What does mutation causing increased methylation do?

Answer 1

Increased methylation = more -tive charge therefore tighter coiling of DNA-histone complex
less likely transcription factors can bind (increased methylation from mutation) therefore gene is not transcribed therefore not expressed.

Question 2

What is a genome?

Answer 2

All the DNA within a cell/organism

Question 3

What does the DNA fragment differentiate by during gel electrophoresis?

Answer 3

Mass, charge, length of amino acid sequence

Question 4

What is the advantage of iPS?

Answer 4

• reduced risk of rejection (patients own cell)
• less demand for donors
• long term treatment, not frequent
• singular treatment
• obtaining sample is painless
• less use of addictive, side effect inducing drugs during rejection therapy

Question 5

What sort of tags (primers/probes) can be used?

Answer 5

• fluorescent dye (glows under uv light)
• enzyme attached to dye (ELISA test sort of thing, releases pigment)
• use during aseptic techniques

Question 6

What does a mutation causing increased acetylation do?

Answer 6

• Less charge difference between DNA and histone
• loose coiling of DNA histone complex
• therefore transcription factors easily reach
• gene expression is permanently SWITCHED ON

Question 7

What is used to form DNA fragments?

Answer 7

restriction enzymes which are complementary to target region therefore specific for genetic fingerprinting

Question 8

What is PCR

Answer 8

• Denaturing: high temp 72 degrees to denature DNA
• Replication: both strands used as templates DNA probes attached complementary to specific target reigon
• Annealing?? Temp reduced to below 50 degrees and taq polymerase to anneal fragments

Polymerase chain reaction, used in amplifying sample sizes for further investigation