Question

1- cite the four majors classes of membrane - forming lipids

2- define the following terms :

1- pI of a protein

2-pKa of a functional group

3-alpha bulge or (pi) helix

Answer 1

Answer 1: Four major classes of membrane-forming lipids:

• Phospholipids
• Glycolipids
• Fatty acids
• Phosphoglycerides

Answer 2:

1. pI of a protein: pI is isoelectric point of a protein which is defined as the pH at which net charge of the protein is zero.
2. pKa of a functional group: pKa of a functional group is defined by its degree of dissociation in water to produce ions.
3. alpha bulge or (pi) helix: can be identified in as a 'bulge' and are determined by their repeating (i+5)(i) hydrogen bonds