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Ch. 10 review: Lipids
•
Working with lipids:
– Analysis of lipid content of a tissue:
1. ‘Dissolve’ tissue components in a mixture of
chloroform, methanol, and water
2. Add water--solution separates into two phases:
aqueous/methanol and organic
•
What is in each phase?
3. Use chromatography to separate lipids of
different polarity
– Name two characteristics of lipids that influence polarity
• Which of the following pairs of lipids would
have the highest melting point?
– (a) stearic acid (18:0) or (b) oleic acid (18:1)
– Oleic acid: omega-9 fatty acid (olive oil)
– (a) palmitoleic acid (16:1) or (b) oleic acid (18:1)
– (a) phosphatidylinositol or (b) triacylglycerol
Why the aliphatic chain?
Ch. 10.7
• When the hormone vasopressin stimulates
cleavage of phosphatidylinositol 4,5bisphosphate by hormone-sensitive
phospholipase C, two products are formed.
What are they? Solubility?
Chapter 11 (Membranes)
• Fluid “Mosaic” model:
– List components of biological membranes
Peripheral vs. Integral Membrane Proteins
• Characteristics
• Purpose
• Peripheral membrane proteins: often
transiently associated with the membrane
– on/off in regulated manner
Lipid fluidity
• How is it an advantage?
• Why does it need to be restricted?
Membrane fusion
• Why is it so difficult?
– Vesicles have to fuse with the plasma membrane at
the right place/time
– Physically: mixing of polar headgroups and
hydrophobic regions
• “Unstable void space” figure 11-25
Solute transport across
membranes
• Simple diffusion
• Facilitated diffusion (a.k.a. passive
transport)
• Active transport
– Primary (chemical energy input (ATP))
– Secondary
Facilitated diffusion
~catalysis
“Side” note:
Primary active transporters (pumps)
P-type ATPases: Ion pumps (metals Na+,K+,Ca2+, etc)
F-type, V-type ATPases: Proton pumps (H+)
-pH regulation, ATP synthesis
Chapter 13: bioenergetics
(problem 18)
Oxidizing agent + n electrons → reducing agent
The E'° values for NAD+/NADH and pyruvate/lactate redox
pairs are -0.32 V and -0.19 V, respectively
(a) What are the oxidizing/reducing agents in the redox
pairs?
(b) Which chemical has the greatest tendency to lose
electrons?
(c) Which is the strongest oxidizing agent?
(d) Under standard conditions, in which direction will the
following reaction proceed?
Pyruvate + NADH + H+ ↔ lactate + NAD+