Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
32 Cards in this Set
- Front
- Back
|
What are the 4 functions of the cell membrane?
|
1) Maintain structural integrity of the cell ( barrier function)
2) Cell-cell interactions and communications 3) Selective permeability and transport of molecules 4) Tranduces extracellular signals |
|
|
What are the lipids in the plasma membrane?
|
-50-70% phospholipids
-25-40% cholesterol 5% glyocolipids |
|
|
Describe properties of the phospholipid molecule
|
-polar hydrophilic head
-2 non polar hyodrophobic fatty acyl tails -amphipathic |
|
|
What are the 4 ways that proteins associate with membranes?
|
-Integral membrane proteins (spans entire lipid bilayer)
-Linked with a fatty acid tail -Peripheral associated with an integral membrane protein -Linked to a specialized phospolipid |
|
|
What is an integral membrane protein and example
|
0Protein itself is inserted into the membrane and usually spans the entire membrane
(Classical G protein coupled receptors and enzyme linked kinase receptors |
|
|
What is a linked with a fatty acid tail protein?
|
-It is a protein that inserts into the bilayer and most often attached to the cytoplsamic side of the membrane
|
|
|
What is a protein linked to a specialized P-ipd
|
It is a protein that is linked to a phospholipid that inserts into the bilayer
|
|
|
What is a peripheral associated with an integral membrane protein
|
It is not a covalent bond interaction, it is ionic in nature and iit could be on the cytoplasmic or extracellular side
|
|
|
Where are carbohydrate groups added to membrane proteins or lipids?
|
They are only added to proteins/lipids on the outside of the cell to form the gylcocalyx
|
|
|
What is synport
|
It is active transport in which symporters which are integral membrane proteins transport 2 substances across the membrane in the same direction
|
|
|
What is antiport?
|
It is active transport in which 2 different molecules are transported in opposite directions across the membrane
|
|
|
Biochemically, the membrane looks like a?
|
Bilayer (inner phosopholipid and outer phospholipid layers)
|
|
|
On a TEM, how does the membrane look like?
|
a trilaminar structure (due to inner head groups/ central hydrophobic tails and outer head groups)
|
|
|
What are forms of passive transport?
|
Simple diffusion
faciliated diffusion ion channel mediated diffusion carrier mediated diffusion |
|
|
What chemicals are used for signaling?
|
Neurotransmitters and hormones
|
|
|
Explain signaling via G protein coupled receptor in brief details
|
-Activates phospolipase C that generates InsP3 and Diacyglycerol
-It is a bifurcating pathway because it splits in two |
|
|
What is insP3
|
it stimulates calcium signaling
|
|
|
what is diacylgylcerol?
|
it stimulatse protein kinase c
|
|
|
What is needed to activate protein kinase c
|
diacylgycerole and Ca 2+
|
|
|
what does protein kinase c do?
|
it activates a phosphorylation cascade, whose end result is the activation of gene regulatory proteins that initiate transcription of specific genes
|
|
|
Explain enzyme linked receptor (kinase) signaling
|
-These are transmembrane proteins, whos extracellular regions act as receptors, when a signalling molecule binds to it, it becomes an enzyme
These are receptors themselves (these kinases); There are two major types - tyrosine kinases and serine/threonine kinases |
|
|
what does the tyrosine kinase do?
|
EGF receptor that signals to Ras/Raf
-Raf kinase is mutated in over a third of all cancers |
|
|
What does the serine/threonine kinase do?
|
an example is a TGFB receptor
|
|
|
What is the largest organelle in the cell?
|
ER
|
|
|
The ER lumen cistern is _____ throughout cell
|
continious
|
|
|
What is the er made of?
|
tubules, flattened/hollow sheets and 3 way junctions where tubules and sheets are interconnected
|
|
|
Rough ER has associated
|
ribosomes
|
|
|
What is the function of rER?
|
protein synthesis/ folding, glycosilation and disulphide bond formation
-qualitty control - er based signalling - prevent diseases |
|
|
what does the ser function in?
|
lipid snythesis and calcium storage
|
|
|
what pathway is the er part of
|
secretory pathway
|
|
|
what is the er a source of?
|
biogenesis of other organelles (peroxisomes and lipid droplets)
|
|
|
the er is a dynamic organelle why?
|
it undergoes fusion and fission reactions and interacts with actin and microtubules
|
