Molecular Genetics

Question 1

Central Dogma

Answer 1

Transcription control

Determines when and what cell a gene is transcribed to mRNA and amount of proteins produced

Question 2

Cell expression

Answer 2

All have the same DNA and protein-coding genes
~1000-2000 unique
turned on/off via transcription

Question 3

Transcription factors

Answer 3

Proteins that bind to specific DNA sequence and control rate of transcription

Question 4

Promoter

Answer 4

Short DNA sequence

Question 5

Promoter role

Answer 5

Transription factors bind to and recruit RNA polymerase

Determine if and how much transcribed

Question 6

Transcribed region

Answer 6

mRNA

Question 7

Gene only expresssed when..

Answer 7

both activators present and repressor absent

= RNA poly recruited

Question 8

Repressor present

Answer 8

Interfers with structure and RNA poly not recruited

Question 9

Law of segregation

Answer 9

When gametes form, allele separate

1 allele of each gene in each gamete

Question 10

Law of independent assortment

Answer 10

Segregation of alleles independent of others
Aren’t inherited together
Except genetic linkage

Question 11

Law of dominance

Answer 11

Dominant/recessive (non functional protein)

Question 12

Phenylalanine breakdown

Answer 12

Early in cycle - deadly as many networks = multiple compounds affected
PKU = health problems
Phen high and tyrosine low
Later = not severe
Black urine

Question 13

Environment effects PKU

Answer 13

Low phenylalanine diet prevents intellectual disability

Question 14

Genetics effects PKU

Answer 14

Transported across blood-brain barrier

Varying efficiency of transporter = greater/lower PHE in brain = more/less damage

Question 15

Mutation = alter function of gene PKU

Answer 15

R408W in PAH gene
R (arg) -> W (try)
Incorrect folding + no active PAH protein made

Question 16

Types of mutations

Answer 16

Substitution
Deletion
Insertion

Question 17

Glucokinase

Answer 17

Enzyme in glucose sensing

Controls how much insulin produced

Question 18

MODY2 results in..

Answer 18

Mild hyperglyeaemia (hetero)
Maturity onset type 2 diabetes in young
Severe diabetes (homo)

Question 19

MODY2 mutation

Answer 19

Glu -> Lys

GC to AT

Question 20

PCR

Answer 20

1) Heat 95 to separate DNA strands
2) Cool to ~60 to anneal DNA primer
3) Heat 72 to allow Taw DNA poly to copy DNA

Question 21

Detecting wild types

Answer 21

HindIII

Restriction enzyme that cuts AAGCTT (MODY2)

Question 22

Using agarose gel

Answer 22

Wild type - 1 band

MODY2 - 2 bands

Question 23

What is cancer

Answer 23

Multiple mutations
In somatic cells
Risk increase with DNA replication
Spontaneous or due to carciogens

Question 24

Cancer cells

Answer 24

No longer respond to signals that control cellular growth and apoptosis
Could be metastasis

Question 25

Types of mutations

Answer 25

Germline - in gametes, passed to next gen

Somatic - in other cells. not passed down to next gen

Question 26

Tumor suppressor gene

Answer 26

Lack of protein that prevent uncontrolled cell growth

Recessive mutation

Question 27

Onco-genes

Answer 27

Dominant mutation on protein that promote cell growth

Increase activity

Question 28

Chronic Myeloid Leukemia Mutation

Answer 28

Translocation b/e chromosomes 9 & 22
ABL gene
ABL + BCR gene fusion

Question 29

Problem with CML

Answer 29

ABL + BCR always active = oncogene

ABL - normally needs signal to activate cell divsion

Question 30

Solutions with CML

Answer 30

Functional tumor suppressor gene prevent cancer

BUT mutation in both = uncontrollable growth

Question 31

Cancer Treatment

Answer 31

Surgery
Radiation therapy
Chemotherapy
Targeted therapy