Lipids

Question 1

What is glycerol?

Answer 1

Molecule which combines with three fatty acids to form triglycerides. It is three carbon chain with three hydroxyl groups.

Question 2

Hydrophilic

Answer 2

Section of a molecule which is attracted to water

Question 3

Hydrophobic

Answer 3

Section of a molecule which is repulsed by water

Question 4

What is a triglyceride?

Answer 4

Individual lipid molecule made up of a glycerol molecule and three fatty acids contain ester bonds

Question 5

What is a lipid?

Answer 5

A class of organic compounds that are fatty acids and their derivatives and are insoluble in water, but soluble in organic solvent e.g. triglycerides, phospholipids, wax and steroids.

Question 6

What is a mono unsaturated fatty acid

Answer 6

Fatty acid, which possesses a carbon chain with a single double bond between carbon atoms

Question 7

What is a phospholipid?

Answer 7

Triglyceride, in which one of the three fatty acid molecules is replaced by phosphate molecule phospholipids are important in the structure and function of plasma membranes

Question 8

Poly unsaturated fatty acid

Answer 8

Fatty acid which possesses a carbon chain with many double bonds between carbon atoms

Question 9

Saturated fatty acid

Answer 9

A fatty acid in which there are no double bonds between the carbon atoms

Question 10

Info, about lipids

Answer 10

Different from proteins and carbohydrates. They are not polymers. They are still organic molecules as they contain hydrogen and carbon they provide a source of energy helped insulate organisms act as waterproofing or membrane in hormones two types of lipids, triglycerides and phospholipids.

Question 11

Triglyceride components

Answer 11

A glycerol molecule and three fatty acid chains

Question 12

Triglyceride bonds

Answer 12

Ester bonds formed by condensation reaction between each of the three 0H groups on the glycerol and the OH group of each fatty acid chain. They are nonpolar 

Question 13

Triglyceride properties

Answer 13

Fatty acid chains are hydrophobic making lipids insoluble and water. They bundle together as insoluble droplets, because the tails face inwards, and the glycerol heads shielded them from the water. The hydrocarbon fatty acid chains can be saturated or unsaturated.

Question 14

Examples of triglyceride

Answer 14

Used as an energy store as there is a lot of energy released when the fatty acid chains are broken down

Question 15

Phospholipids components

Answer 15

A glycerol molecule and phosphate group and two fatty acid chains

Question 16

Phospholipid bonds

Answer 16

Esther bond formed by condensation reaction between two 0H groups on the glycerol and the OH group of each fatty acid chain

Question 17

Phospholipid properties

Answer 17

Phosphate group is hydrophilic, and the fatty acid chains are hydrophobic. This allows phospholipids to form bilayers, which make up membranes in and around cells.

Question 18

Phospholipid examples

Answer 18

Membranes hormones, e.g. testosterone

Question 19

Saturated fatty acids

Answer 19

Don’t have any double bonds between their carbon atoms. The fatty acid has all the hydrogen it can hold or is saturated with hydrogen.

Question 20

Unsaturated fatty acids

Answer 20

Have double bonds between carbon atoms, which means they contain few hydrogen atoms. The double bond also causes the chains to bend or kink in saturated fatty acid chains can contain one or many carbon double bonds. 

Question 21

Phospholipid bilayer

Answer 21

Phospholipid heads are hydrophilic, and their tails are hydrophobic so placed in water. They form a double layer with the heads facing outwards towards the wood, and their tails facing inwards away from the water. The centre of the bilayer is therefore hydrophobic so water soluble substances cannot pass through. This creates a barrier, allows separation of solutions and create different conditions either side of the membrane.

Question 22

What are sterols

Answer 22

Also known as steroid alcohols and another type of lipid found in cells. They are not fats or oils have very little structurally in common with them. They are complex alcohol molecules based on a carbon ring structure with a OH group at one hand they have jewel hydrophilic at hydrophobic characteristics, e.g. cholesterol 

Question 23

Cholesterol

Answer 23

The body manufacturers cholesterol, primarily in the liver and intestines plays an important role in the formation of cell membranes, becoming position between the phospholipids, adding stability of cell membrane and regulates the fluid, keeping the membranes fluid at low temperatures and stopping them becoming too fluid high temperatures

Question 24

Steroid hormones made from cholesterol

Answer 24

Testosterone oxygen and vitamin D because they are small and hydrophobic they can pass through the hydrophobic part of the cell membrane