CELL BIOLOGY EXAM QUESTIONS Flashcards
DISCUSS THE ETHICAL ISSUES OF THERAPEUTIC CLONING
therapeutic cloning involves producing embryos from which embryonic stem cells can be harvested for medical use
:)
any procedure that reduces pain and suffering is morally justified
stem cells can be used to replace organs/tissues that have been lost/damaged in a patient
pain and suffering can be reduced/lives can be saved/quality of life can improve
cells can be removed from embryos that have stopped developing and would have died anyway
cells are removed at a stage when no pain can be felt by the embryo
use embryo from IVF that would otherwise be destroyed
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embryonic stem cells are no longer needed as adult stem cells can be used w/o causing loss of life
there is danger of embryonic stem cells developing into tumour cells
every human embryo is a potential human with the rights to development
any procedure that harms a life/ kills is unethical/ morally wrong
OUTLINE THE ROLE OF PROTEINS IN ACTIVE AND PASSIVE TRANSPORT OF MOLECULES THROUGH MEMBRANES
channel proteins allow diffusion/osmosis/ passive transport
large/ polar molecules cannot cross the membrane freely
facilitated diffusion involves moving molecules through protein down their concentration gradient w/o ATP
active transport involves moving molecules through proteins against their concentration gradient w/ ATP
some proteins in the membrane are pumps/Na-K
OUTLINE THE ROLE OF CYCLINS
a. cell cycle is a sequence of stages / cell cycle is G1, S, G2 and mitosis
b. (control of the cell cycle) by cyclins/cyclin
c. levels of cyclins rise (and fall)/fluctuate during the cell cycle/surge at different times/have to reach a certain concentration
d. conditions inside as well as outside the cell affect regulation
e. four cyclins/different cyclins to enter different stages of/events in the cell cycle / cyclins
regulate the sequence/timing of the cell cycle / cyclins trigger the next stages
f. cyclin-dependent kinases / cyclins bind to kinases and activate them
g. kinases phosphorylate other proteins
h. phosphorylated proteins perform specific functions in the cell cycle
