Lipids - Retrieval Questions 2

How does the hydrophilic and hydrophobic ends of the phopholipids interact with water?

The phospholipids may:
- ...form a layer on the surface of the water.
- ...form a micelle.
-...form a bilayer.

What are fatty acids?

Organic acids that have a carboxyl group joined to a hydrocarbon tail.

What is glycerol?

An organic alcohol that has three hydroxyl groups.

What chemical elements do lipids contain?

Carbon
Hydrogen
Oxygen

What is the head of the phospholipid made of?

Phosphate group
Glycerol molecule

Why are triglycerides not considered a polymer?

Because they are not composed of monomers

How do phospholipids behave in water?

When a phospholipid is surrounded by water, the hydrogen ions dissociate from the phophoric acid.
This forms a phosphate group with a negative charge.

What type of molecules are triglycerides?

Lipids

What are phospholipids?

A type of lipids that is similar to triglycerides in structures.

What is a hydrophobic molecule?

A molecule that is repelled by water due to it not having a charge.

Why does the membrane act as an electrical insulator?

Because it insulates against charge because charged ions cannot pass through the phospholipid bilayer.

Why do lipids not dissolve in water?

Because they are not polar molecules .

Name the role of triglycerides.

They are a good source of energy.

Why is it important that the phosphate group is negative?

It makes sure that the phospholipid head is hydrophillic.

What is the structure of a triglyceride molecule?

Triglycerides are formed from one molecule of glycerol and three fatty acids.