Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. How different are the
    location of ribosomes in
    eukaryotic and in prokaryotic
    cells?


In prokaryin cytoplasm.otes ribosom In eukaryotices are found free cells they
can also be found free in cytoplasm amainly adhered to the external nd
membrane of the karyotheca and of the
rough endoplasmic reticulum.



  1. How is the finding of
    ribosomes inside mitochondria
    and chloroplasts explained?


It is a strong hypothesis that


mitochoprokaryotes that associated to pndria and chloroplasts wererimitive (^)
eukaryotic cells under mutualism
(gaining protection aenergy). This explains why nd offeringwithin thos (^) e
organelles there are DNA and protein
synthesis machiribosomes. This hypothesis isnery, includin known asg (^)
the endosymbioticorigin of mitochondria and chloroplasts. hypothesis on the



  1. What are some examples of
    human cells that produce
    proteins for exportation?
    Which cytoplasmic organelle
    is expected to be well-
    developed and abundant in
    those cells?


Specialized Langerhans cells ofcells of the glands, lik the pancreas (thate the


produce insulin) ocells, are examples of secretory r the saliva-producingcells. In (^)
cells specialized in secretion, the
endoplasmicapparatus ar reticulum ae well-developed since thnd the Golgi (^) ey
participate in the storage and
processing of proteins for exportation.



  1. Which are the more
    abundant ribosomes in
    secretory cells - the free
    cytoplasmic ribosomes or
    those associated with the
    rough endoplasmic reticulum?


Free cytoplasmicrelated to protein p ribosomroduction fes are moreor internal (^)
cellular consumption while those
adhered to threticulum are e rough endoplasmicmore important in protein (^)
synthesis for exportation. Proteins made
by adhered ribosomendoplasmic reticulum aes enter the roughnd are later
transferred to the Golgi apparatus. So in
secretory cellsendoplasmic reticulum ar ribosomes adhered to thee more
notable.



  1. Where in eukaryotic cells
    does mRNA synthesis occur?
    To where do these molecules
    migrate?


Messenger RNA molecules arsynthesized within the nucleus, pe (^) ass
through pores of the nuclear and gain the cytoplasm to reach thmembranee
ribosomes where protein synthesis
occurs.
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