B.2.2 + B.2.3 Flashcards
structures in Eukaryotic cells that are not organells
- cell wall: outside cell
- cytoplasm: has diverse functions
- cytoskeleton: has diverse functions
seperation of nucleus and cytoplasm in eukaryotes
- transcription occurs in nucleus and mrna is produced. this is then released from nucelar pores. between this time DNA motifications reduces errors that could be made in tranlsation.
- in prokaryotes no nucleus means this modification cannot occur
advantages of compartimization in eukaryotes
- allows for enzymes and substrates to be close to one another
- PH can be kept ideal
- incompatiable bichemicals can be kept separte
- during encoytyosis a phagocyticvacuole can keep harmful substances seperate
endocytosis
uptake of large particles
exocytosis
export of large molecules
fertilization
fusion of a male and female gamate to produce a single celled zygote
- zygotes then divide many times to form a embry0
mitosis in cell cell divison
mitosis means that the cells in embroyes have all the genetic material and giving them the ability to differenciate in any way- unspcialised
morphoegns
- certain cells in embryo
- they are regulators of gene expression altering protein formed and cell formation
- the concentration of morphogens dechipers a cells position in the embro and the differenction pathway a cell becomes
- receptors in cells surface detect hpw far away they are from the secreting cell
stem cells
undifferentiated cells that are self replicating
- they can self renew and differentiate
partial differentiation is when stem cells can only produce certain things
a cells ability to differenciate is called
potency
totipotent
- early stage of animal embryo
- cam differenciate into any cell
- can give rise to whole organism
pluripotent
- in development of embro
- can diffencitate into many cell types
- cannot rise whol eorganism
multipotent
- in adult tissue
- can differenciate into specific cells eg the bown marrow stuff
stem cell niche
precise location of stem cells withing a tissue. it must provide a microenvoenvrionment whereby cells can remain inactive and undifferenciated for a long time
unipotent
can only develop new cells of itself
bone marrow
- in the middle of large bones
- haematopoietic stem cells
- replaces blood cells white blood cells and platlets
- bone marrow recives a genourous supply of oxygn 15% of blood from heart
hair follicle
mores in skin that holds hair stem cells
- they provide all the cells neede for constant hair growth
male gammete
- 3um wide 50um long for swimming
blood cells
- 7um wide 1-2um thick
allows movement in narrow pathways and large surface for oxygen - whit blood cells inactive 10-12um active is 30 for protein synthesis and antibody production
female gammates
- 110 um
- contains cytoplasm for enegey and food
neurons
- very very long for messages
sirated muscle
- 300mm long
sa;v ratio
if cells get too large volume the SA cannot keep up
this causes cell devison to procide exchange of materials enough for the oranism
examples of stem cell USE
- Leukemia treatment: Bone marrow transplants replace damaged blood-forming stem cells in leukemia patients.
- Diabetes treatment: Stem cells can be differentiated into insulin-producing pancreatic cells, which could help treat Type 1 diabetes.
Stem cells provide a way to test new drugs for safety and effectiveness before human trials. This is particularly useful in drug development because:
Scientists can grow stem cells into specific tissues or organ-like structures (e.g., liver, heart, or brain cells) to see how a drug affects them.
