lipids 2

Question 1

what are fatty acids

Answer 1

the main building blocks of membranes

they are long hydrocarbon chains ending with a carboxyl group

can be saturated or unsaturated

Question 2

how does chain length impact melting point

Answer 2

longer chain have larger melting points

further saturated have higher melting points

Question 3

how are fatty acids stored

Answer 3

in the form of triglycerols, attached to a glycerol backbone

Question 4

what is a glycerolipid

Answer 4

a fatty acid storage unit that contains:

1) glycerol
2) fatty acid
3) phosphate
4) alchol

Question 5

what is a sphingolipid

Answer 5

a storage unit that contiains
fatty acid
phosphate
alcohol
and sphingosine

Question 6

what is a glycolipid

Answer 6

a fatty acid storage unit that contains
fatty acid
sphingosine
and a sugar mole (glucose or gal)

Question 7

what are phosphoplycerolipids

Answer 7

the simple phospholipd form:

fatty acid
glycerol
and phosphate

NO alcohol, though larger moles contain lipids

Question 8

what are steroids

Answer 8

contains a tera-cyclic arrangement. 3 6 mems and 1 5 meme with alcohol. These moles insert into the membrane and influence its fluidity of it. at lower temps, mem with high cholesterol will be more fluid, but at higher temps the membrane will be less fluid

Question 9

how do membrane lipids and proteins move

Answer 9

by latteral diffusion

Question 10

what is the purpose of a membrane

Answer 10

to separate a cell from its enviroment and graduated what is able to enter/ leave (via prtoien transport systems)

Question 11

how does nut get into and out of the cell

Answer 11

passive diffusion across mem

facilitated diffusion through a hydrophobic channel

active transport using a pump

Question 12

how much of the mem is protein

Answer 12

50%

Question 13

integral vs peripheral proteins

Answer 13

integral are full inserted into the meme while peripheral exists on the outside

Question 14

how do proteins become integrated into the membrane

Answer 14

via the use of alpha helices on the extremities of the protein. the helices are non-polar/ hydrophobic and interact with the HC in the middle of the bilayer. B sheets may be sued aswell

Question 15

explain the Na K pump

Answer 15

this pump facilitates the transfer of glucose into the cell for glycolysis. The pump uses Atp to move 2 K+ into the cell and 3Na= out of the cell. this goes against the Na gradient, inorder to power the SGLT (symporter)

Question 16

explain the role of the K channel

Answer 16

the K Na pump created membrane potential, though it’s only really needed for Na. To let the K out of the cell the K channel is used. the channel has a selectivity filter to make sure no cells larger than 1.5 A are let out.

For K to enter the channel it loses its out shell (solvated) and is stabilized by the O atoms embedded in the protein. the Inos move through the channel, effectively being pushed out by the introduction of another (repulsion) that entrance (there are 4 sites.)