Week 1-3 Flashcards
Euchromatin
Genes that are expressed
Hetrochromatin
Genes that aren’t expressed
What are histones
Proteins that bind to DNA
What is the function of the major and minor grooves
To allow proteins to attach to the DNA
What are histone and histone tails rich in
Lysine or arginine (positively charged)
What is the function of an H1 linker
It clamps to the nucleosomes and helps them connect more
What are the 4 types of histones
H2A, H2B,H3,H4
What are the 4 stages of the cell cycle
G1 phase
S phase
G2 phase
Mitosis
Where do the kinetochore form and spindle fibres attach
Centromere
What divides the cytoplasm
A contractile ring
What happens during the G0 phase (restriction point)
Growth arrest
It’s still metabolically active
But it doesn’t replicate/proliferate
What are cdks
They are kinases (enzymes) that phosphorylate protein to allow the cell cycle to go forward
How are cdks activated
By the binding of cyclins
Name the 3 different cyclins
G1/S cyclin
S cyclin
M cyclin
What is the hayflick limit
It’s the number of times dna and a cell can divide before it stops because of the telomere shortening, once the telomeres are too short dna and cel division stop.
Name the two functions of DNA
It’s a hereditary molecule & allows for protein synthesis to occur (central dogma)
What is another name for transcription factors
Gene regulatory proteins
What do pioneer transcription factors do
They bind to dna to start the opening of the chromatin
What triggers the binding of pioneer transcription factors
A signal that communicates with them
Name the two domains that transcription factors have
- Binding domain
- Trans-activation domain
What are transcription factors
Proteins that bind to dna to change the chromatin structure and gene expression
What is the function of transcription factors
They help recruit other transcription factors, chromatin modifiers and the GTC (general transcription complex)
