BIO SCI 93 Study Guide - Quiz Guide: Ribosomal Rna, Detoxification, Pseudopodia


Department
Biological Sciences
Course Code
BIO SCI 93
Professor
Jorge Busciglio Kim Green Marcelo A Wood
Study Guide
Quiz

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FUNCTIONS OF A CELL!
!
Cell parts
Functions
plasma
membrane
-enclose the cell.!
-a selective barrier that allows passage of enough oxygen, nutrients, and wastes
to service the entire cell!
-consists bilayer of phospholipids with various proteins (with carbohydrate side
chains) embedded in it. !
-participate in cell’s metabolism because enzymes are built right into the
membranes.
Nucleus
-Contains most DNA!
-Directs proteins by synthesizing mRNA according to the instructions of DNA;
mRNA is transported to the cytoplasm via nuclear pores; ribosomes translate
the mRNA’s genetic message into the primary structure of a specific
polypeptide. !
-Pore complex: lines each pore, regulates the entry and exit of proteins and
RNAs and large complexes of macromolecules.!
-Nuclear lamina (a netlike array on the inner surface of nuclear envelope) and
nuclear matrix (a framework of protein fibers throughout the nuclear interior)
organize the genetic material so it functions efficiently.!
-Nuclear envelope: double membrane enclosing the nucleus; perforated by
pores, continuous with ER.!
-Nucleolus (plural: nucleoli): nonmembranous structure involved in production
of ribosomes; rRNA is synthesized from the instruction of DNA; proteins
imported from the cytoplasm are assembled with rRNA into large and small sub
unites ribosomes, which then exit the nucleus through the nuclear pores to the
cytoplasm, where a large and a small subunit can assemble into a ribosome.!
-Chromatin: material consisting of DNA and proteins; visible in a dividing cell as
individual condensed chromosomes.
Ribosomes
-made of rRNA and protein.!
-make proteins that are destined for insertion into membranes, for packaging
within certain organelles such as lysosomes or for export from the cell
(secretion)!
-Cells that specialize in secretion (cells of pancreas that secrete digestive
enzymes) have high proportion of bound ribosomes.
Golgi apparatus
-active in synthesis, modification, sorting, and secretion of cell products.!
-Cisternae carries and modifies their cargo as they move.!
-identification tag (phosphate groups)!
1. Vesicles move from ER to Golgi!
2. Vesicles coalesce to form new cis Golgi cisternae.!
3. Cisternal maturation: Golgi cisternae move in a cis-to-trans (receive-to-ship)
direction.!
4. Vesicles form and leave Golgi, carrying specific products to other locations or
to the plasma membrane for secretion.!
5. Vesicles transport some proteins backward to less mature Golgi cistern, where
they function.!
6. Vesicles transport certain protein back to ER, their site of function.
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