mechanisms of cell deviance

Question 1

how can mutations be prevented

Answer 1

cell cycle controle
proof reading
degenerate genetic code

Question 2

how does cancer occur?

Answer 2

if a mutation gives a cell an advantage it will proliferate.
paracrine signalling cause neighbouring cells to proliferate.
mutates again advantage continues to outcompete neighbouring cells
3rd increased advantage leads to too much proliferation and cells become invasive.

Question 3

what is a gain of function mutation that can lead to cancer

Answer 3

Oncogene

Question 4

what is a proto-oncogene

Answer 4

pre oncogone
aka the gene involved in cell growth

Question 5

what are the functions of RAS proteins?

Answer 5

signal cell proliferation

Question 6

what is neoplasia

Answer 6

new growth

Question 7

what is neoplasm

Answer 7

uncontrollable growth

Question 8

what is oncology

Answer 8

swelling

Question 9

what is anaplasia

Answer 9

loss of differentiation

Question 10

how can a mutation in RAS proteins lead to cancer

Answer 10

mutation stops GTP hydrolysing, meaning the RAS will always be active, leading to excess proliferation

Question 11

what is a tumour supressor gene, and how can a mutation in it lead to cancer?

Answer 11

a loss of function
it is recessive so there must be a mutation in both alleles in order for it to no longer inhibit proliferation

Question 12

what proteins are found in most tumour supressor genes

Answer 12

P53

Question 13

what causes a mutation in both alleles

Answer 13

mitotic recombination
gene conversion
frameshift mutations

Question 14

what is senescence

Answer 14

when cells loose their ability to proliferate

Question 15

give an describe antagonistic pleitropy

Answer 15

testosterone producing cells will stop proliferating after pubity

Question 16

what can cause senescence

Answer 16

DNA damage
Chromatin remodelling
chronic age
telomere shortening

Question 17

what is oxidative stress?

Answer 17

the imbalance between pro-oxidants species and antioxidants

Question 18

what does too many Reactive Oxidative Species cause

Answer 18

in the mitochondria, too many ROS lead to DNA damage

Question 19

what are the enzymatic antioxidants

Answer 19

catalase
glutathione
thioredoxin
superoxide dismutase

Question 20

what are the non enzymatic antioxidants

Answer 20

reduced glutathione
vitamine C + E

Question 21

what are some pathological responses

Answer 21

Cytosine oxidation
lipid peroxidation
mitochondrial disfunction
genetic instability

Question 22

what is AGE

Answer 22

advanced glycation end product
sugars attach to proteins, DNA and lipids

Question 23

give an example of AGE

Answer 23

pro oxidants
pro inflammitories

Question 24

what causes age

Answer 24

nutrition
radiation

Question 25

what are chaperones, how do they work?

Answer 25

repair / assist protein folding sends signal to ER to repair the protein

Question 26

what causes protein misfolding

Answer 26

loss/ gain of function mutations

Question 27

what is a prion?

Answer 27

protein that triggers a normal protein to fold abnormally

Question 28

give an example of a disease where a prion is found?

Answer 28

BSE Mad cow disease the PrP2 mutated to PrPse prion Alpha helix mutated to a Beta sheet

Question 29

give an example of a disease where the protein has a loss of function mutation

Answer 29

Cystic Fibrosis

Question 30

give an example of a disease where a protein had a gain of function mutation

Answer 30

Alzheimer (Beta amyloid) Parkinsons (alpha synclein) Hunningtons (HTT mutated)