Lipids

Question 1

Similarities and differences of lipids with carbohydrates

Answer 1

Both = carbon, hydrogen and oxygen
C= soluble, 2:1 ratio of H to O
L = insoluble due to fewer polar covalent bonds as there are fewer O atoms, dont have 2:1 ratio

Question 2

How do lipids become soluble

Answer 2

form complexes with proteins, lipids are surrounded by protein. These are lipoproteins

Question 3

Examples of lipids

Answer 3

Fatty acids, steroids, eicosanoids (20 carbon lipids), phospholipids, fat soluble vitamins (A,D,E,K), lipoproteins, triglycerides

Question 4

What are fatty acids

Answer 4

carboxyl group attached to a hydrocarbon chain
Used in formation of triglycerides and phospholipids

Question 5

How can fatty acids be used to generate ATP

Answer 5

Fatty acids are catabolised

Question 6

Unsaturated vs saturated, diff types of saturated fatty acids

Answer 6

Unsaturated = hydrocarbon chain have single covalent bonds, each carbon atom saturated by H
Saturated = hydrocarbon chain have one or more double bonds
Monounsaturated = one double bond
Polyunsaturated = more than one double bond

Question 7

How are triglycerides formed

Answer 7

3 carbon glycerol (backbone of triglyceride) combines with 3 fatty acids in 3 condensation reactions forming 3 ester bonds

Question 8

Fats vs oil

Answer 8

Fat = triglycerides that consist of saturated fatty acids
Oil = triglyceride that consists of unsaturated fatty acids

Question 9

draw the ester bonds and ester group

Question 10

Function of triglycerides

Answer 10

Insulation, energy storage (twice as much as carbohydrates), protection

Question 11

what is the adipose tissue

Answer 11

Tissue where excess fats, proteins, oils, carbohydrates are stored as triglycerides

Question 12

Structure of phospholipid

Answer 12

Glycerol backbone with two fatty acid tails (one unsaturated and one saturated)
The phosphate head attaches a charged group (usually containing hydrogen) to the third carbon

Question 13

Structure of steroid

Answer 13

Four carbon rings and a hydroxyl group, many have a short hydrocarbon tail.

Cholesterol is a steroid that can synthesise other steroids

Question 14

Function of steroids

Answer 14

Cholesterol = cell membrane rigidity, precursor of bile salts and steroids
Bile salts = lipid digestion and absorption
Adrenocortical = stress, metabolism, water and salt level
Sex hormones = reproductive functions
Vitamin D = calcium levels and bone growth & repair

Question 15

What are eicosanoids

Answer 15

eicosanoids are lipids derived from 20 carbon long fatty acids that are called arachidonic acid

Question 16

What are the subclasses of eicosanoids

Answer 16

leukotrienes and prostaglandins

Question 17

Leukotrienes functions

Answer 17

Inflammatory response
hormone response regulation
Prevent stomach ulcers
regulate body temperature

Question 18

prostaglandins functions

Answer 18

inflammatory and allergic response