Exam Two: Ch 8 Learning Objectives Flashcards
What is the general structure of a fatty acid?
hydrocarbon chain with a carboxylic acid
What is the difference between a saturated and unsaturated fatty acid?
saturated - no double bonds
unsaturated - all double bonds are cis
Discuss the melting point of fatty acids
more C> less C
C=C< C-C
What are five types of lipids?
fatty acids, triaglycerolds, glycerophospholipids, sphignolipids, and steroids
What is the functional group found in triaglycerols?
esters
What is the functional group found in glycerophospholipids?
Phos bonded to 4 O’s
1 double bond
1 neg charge
2 bonded to R groups
What is the functional group found in sphingolipids?
N
What is the functional group found in steroids?
C3OH group
Describe characterisitcs of a lipid bilayer
structural basis for biological membranes
formation driven by hydrophobic effect
bilayer formation by phospholipids
viscocity increases closer to lipid head group
Lipid bilayers have fast __ diffusion and slow ___ diffusion
lateral; transverse
What are three types of lipid linked proteins?
prenylated proteins
fatty acylated proteins
glycosylaphosphatidylinositol-linked proteins (GPI)
Define lipid linked proteins.
covalently attached lipid may modify structure and activity of its attached protein; may mediate protein-protein interaction
Describe Prenylated proteins
lipid built from isoprene units
most common is C-terminus tetrapeptide (C-X-X-Y) where Y is Ala, Met, or Ser
Describe Fatty acylated proteins
myristic or palmitic acids
many participate in transmembrane signaling
Where are GPI located?
on exterior of the protein
Describe characteristics of integral membrane proteins
asymmetrically oriented amphiphiles
surface labelling technique
What is the surface labelling technique?
employs agents that react with proteins but cannot penetrate membranes; found on integral proteins
Describe characteristics of peripheral proteins
associated loosely with membrane through electrostatic or H-bonding interactions
dissociate under mild conditions; high salt/pH changes
bind at surfaces to certain lipid or integral proteins
Define the fluid mosaic model
accounts for lateral diffusion, where the integral proteins are ‘icebergs’ in a lipid sea in a random mosaic distribution
What is the composition of the sodium potassium pump?
alpha and beta subunits
In the sodium potassium pump, there are _ sodium __ and _ potassium __
3 outside
2 inside
What is the function of sodium potassium pump?
acts as an antiport generating a charge separation across a membrane
What is the key to the sodium potassium pump?
phosphorylation of a specific Asp residue of transport protein
