Cell Biology Flashcards
what cell cycle determines cell cycle length?
G1 (duplication). affected by growth factors.
when is G0?
after G1 variably.
where are ribosomes made?
nucleolus
double membrane nucleus?
outer is contiuous with RER.
where does steroid hormone bind its receptor?
in the cytoplasm, then enters nucleus to act as transcription factor (directly binds DNA).
where does thyroid hormone bind its receptor?
in the nucleus; acts as transcription factor
purines?
guanine
adenine
pyrimidines?
cytosine
thymidine
uricil (R)
how many H bonds in GC and AT/U
3 in GC
2 in AT AU
in glycolysis, how much ATP and pyruvate made from 1 glucose molecule?
2 ATP and 2 pyruvate.
where does Krebs cycle occur?
inner matrix of mitochondria (2 membrane).
products of Krebs cycle?
NADH and FADH2 from 2 pyruvate (from glucose)
go on to form total 2(glycolysis)+ 2(Krebs)+ 34(ETC) ATP from 1 glucose
what else can enter the Krebs cycle?
amino acids, ketones, short chain fatty acids.
gluconeogenesis reactants and products?
lactic acid (cori cycle) and amino acids (#1 alanine) make GLUCOSE
why can’t fat/lipids be available for GNG (in setting of starvation)?
because acetyl CoA (breakdown of fat metabolism) cannot be converted back to pyruvate.
cori cycle products?
lier converts muscle lactate into new glucose (using pyruvate)
how does golgi apparatus modify proteins?
carbohydrates then transport to cellular membrane/secrete/lysosomes
what organ has a lot of RER?
pancreatic acinar cells.
what organ has a lot of SER?
liver and adrenal cortex (lipids and steroid synthesis)
phagosomes (large) and endosomes (small) have to fuse with what to degrade particules?
lysosomes.
three major signaling pathways?
phospholipase C, protein kinase A, MAPK/ERK
phospholipase C
PIP2 into DAG and IP3; increase Ca from SER.
protein kinase C
Ca and DAG activates…. phosphorylates other proteins.
protein kinase A
cAMP acrivates… phosphorylates other proteins.
myosin vs actin
myosin THICK filmaments;
actin THIN filaments
