Exam Two: Ch 8 Learning Objectives

Question 1

What is the general structure of a fatty acid?

Answer 1

hydrocarbon chain with a carboxylic acid

Question 2

What is the difference between a saturated and unsaturated fatty acid?

Answer 2

saturated - no double bonds
unsaturated - all double bonds are cis

Question 3

Discuss the melting point of fatty acids

Answer 3

more C> less C
C=C< C-C

Question 4

What are five types of lipids?

Answer 4

fatty acids, triaglycerolds, glycerophospholipids, sphignolipids, and steroids

Question 5

What is the functional group found in triaglycerols?

Answer 5

esters

Question 6

What is the functional group found in glycerophospholipids?

Answer 6

Phos bonded to 4 O’s
1 double bond
1 neg charge
2 bonded to R groups

Question 7

What is the functional group found in sphingolipids?

Answer 7

N

Question 8

What is the functional group found in steroids?

Answer 8

C3OH group

Question 9

Describe characterisitcs of a lipid bilayer

Answer 9

structural basis for biological membranes
formation driven by hydrophobic effect
bilayer formation by phospholipids
viscocity increases closer to lipid head group

Question 10

Lipid bilayers have fast __ diffusion and slow ___ diffusion

Answer 10

lateral; transverse

Question 11

What are three types of lipid linked proteins?

Answer 11

prenylated proteins
fatty acylated proteins
glycosylaphosphatidylinositol-linked proteins (GPI)

Question 12

Define lipid linked proteins.

Answer 12

covalently attached lipid may modify structure and activity of its attached protein; may mediate protein-protein interaction

Question 13

Describe Prenylated proteins

Answer 13

lipid built from isoprene units
most common is C-terminus tetrapeptide (C-X-X-Y) where Y is Ala, Met, or Ser

Question 14

Describe Fatty acylated proteins

Answer 14

myristic or palmitic acids
many participate in transmembrane signaling

Question 15

Where are GPI located?

Answer 15

on exterior of the protein

Question 16

Describe characteristics of integral membrane proteins

Answer 16

asymmetrically oriented amphiphiles
surface labelling technique

Question 17

What is the surface labelling technique?

Answer 17

employs agents that react with proteins but cannot penetrate membranes; found on integral proteins

Question 18

Describe characteristics of peripheral proteins

Answer 18

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

Question 19

Define the fluid mosaic model

Answer 19

accounts for lateral diffusion, where the integral proteins are ‘icebergs’ in a lipid sea in a random mosaic distribution

Question 20

What is the composition of the sodium potassium pump?

Answer 20

alpha and beta subunits

Question 21

In the sodium potassium pump, there are _ sodium __ and _ potassium __

Answer 21

3 outside
2 inside

Question 22

What is the function of sodium potassium pump?

Answer 22

acts as an antiport generating a charge separation across a membrane

Question 23

What is the key to the sodium potassium pump?

Answer 23

phosphorylation of a specific Asp residue of transport protein