BCHM 316 Lecture Notes - Lecture 23: Glycerol, Chylomicron, Cyclooxygenase
1 Jun 2018
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Functions of phospholipids/bilayer structure
Functions of phospholipids
1. Components of membranes
2. Source of intracellular signals
3. Form lipoprotein particles which help to transport triglyceride and cholesterol in blood
Components of membrane
Phospholipids are made of a polar hydrophilic (water-loving) head-group and a hydrophobic
hydrocarbon tail. This molecule sits between the lipid-soluble and water-soluble phases. AKA the cell
surface.
Sources of intracellular signals
- There are three different signals that can be formed
o Fatty acid signals
o Diacylglycerol
o Inositol triphosphate (IP3)
- Arachidonate and its products (prostaglandins and leukotrienes) are an example of fatty acid
signals
- Diacylglycerol activates protein kinase C
- IP3 is only from PIP2, IP3 activates release of intracellular Ca2+ stores
Phospholipid has two fatty acids, a glyceryl
backbone, a phosphate group, and a molecule
at position number three.
Different phospholipases cleave at different
spots.
Phospholipase A1 and phospholipase A2 can
cleave between the C-O bond so like the bond
between the hydroxyl group from the glyceryl
backbone and the carboxylic group from the
fatty acid.
On the other hand, phospholipase C and
phospholipase D cleave between the PO4-O bond.
Specifically, phospholipase D allows for the base to be released.
find more resources at oneclass.com
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Document Summary
Functions of phospholipids: components of membranes, source of intracellular signals, form lipoprotein particles which help to transport triglyceride and cholesterol in blood. Phospholipids are made of a polar hydrophilic (water-loving) head-group and a hydrophobic hydrocarbon tail. This molecule sits between the lipid-soluble and water-soluble phases. There are three different signals that can be formed: fatty acid signals, diacylglycerol. Arachidonate and its products (prostaglandins and leukotrienes) are an example of fatty acid signals. Ip3 is only from pip2, ip3 activates release of intracellular ca2+ stores. Phospholipid has two fatty acids, a glyceryl backbone, a phosphate group, and a molecule at position number three. Phospholipase a1 and phospholipase a2 can cleave between the c-o bond so like the bond between the hydroxyl group from the glyceryl backbone and the carboxylic group from the fatty acid. On the other hand, phospholipase c and phospholipase d cleave between the po4-o bond. Specifically, phospholipase d allows for the base to be released.
