Lipids

Question 1

What three elements do lipids contain?

Answer 1

carbon hydrogen oxygen

Question 2

What can lipids dissolve in?

Answer 2

Other nonpolar substances such as lipids. Not water as water is polar. The inner charges cannot surround solid particles of lipids

Question 3

State the functions of lipids.

Answer 3

Energy source and storage, protection, oxidation, important components of cell membranes, waterproofing, thermal insulation, buoyancy, electrical insulators and steroids & hormones.

Question 4

What can lipids aid in the protection of?

Answer 4

Organs like the kidneys

Question 5

How are lipids a source of energy and storage for that energy ?

Answer 5

In animals in achipose tissue - fat provides twice as much energy as the same mass of carbohydrates. Up in plants seeds contain oil and this provides nutrition until they they develop leaves for photosynthesis.

Question 6

How do lipids play a role in oxidation?

Answer 6

They are part of the oxidation of triglycerides to produce metabolic water.

Question 7

How do lipids play a role in cells?

Answer 7

They are important components of cell membranes as phospholipids.

Question 8

How do lipids play a role in waterproofing?

Answer 8

Implants that is the waxy cuticle which reduces water loss and is made of lipids. In animals aquatic birds have oils on their feathers.

Question 9

How do lipids play a role in thermal insulation?

Answer 9

They are poor thermal conductors

Question 10

Give an example of where lipids provide buoyancy for an animal

Answer 10

Whales

Question 11

What role do lipids play in nerve cells and schwann cells ?

Answer 11

Electrical insulators

Question 12

What are lipids constitutes of beginning with s and h?

Answer 12

Steroids and hormones

Question 13

How many molecules are triglycerides made up of and what are they?

Answer 13

They made up of two types of molecules 1 glycerol and 3 fatty acids.

Question 14

What does molecule of glycerol look like?

Answer 14

There are three 3 carbons linked together each with an OH group and otherwise bonded to hydrogen atoms.

Question 15

What do fatty acids look like?

Answer 15

There is a long hydrocarbon chain and at the end and a final carbon atom is bonded to another carbon atom, with a double bond to an oxygen atom and a bond to an OH group aka a carboxylic acid group.

Question 16

What do triglycerides look like?

Answer 16

Triglycerides have have fatty acids attached to each of the carbon groups where the OH would have been but which is removed during condensation.

Question 17

What are the features of fatty acids?

Answer 17

They can be from 14 to 22 CH2 units long. They are long molecules with a polar hydrophilic end and a non-polar hydrophobic tail. Fatty acids can be saturated or unsaturated.

Question 18

Define saturated fatty acids

Answer 18

There are no double carbon Bonds in the hydrogen chain meaning every carbon of saturated with hydrogens. They form straight chains and have a high melting point. They are a solid at room temperature. Tend to be sourced from animals.

Question 19

Define unsaturated fatty acids

Answer 19

There are one or more double carbon Bonds in the carbon chain meaning that not every carbon is saturated with hydrogen atoms. Unsaturated fatty acids with more than one carbon-carbon double bond are called poly unsaturated fatty acids. Unsaturated fatty acids form bent chains and have a low melting point. They are a liquid at room temperature. Tend to be found in plants.

Question 20

What products exit or leave in the the condensation of a triglyceride molecule?

Answer 20

3 water molecules are produced

Question 21

What products exit or leave in the hydrolysis of a triglyceride molecule?

Answer 21

3 water molecules break the molecule.

Question 22

Where are the water molecules that are involved in condensation and hydrolysis located in triglyceride molecules?

Answer 22

They are both of the OH groups from the ends of the carboxylic acids on the fatty acids and and on the carbon atoms of the glycerol molecule.

Question 23

What are the bonds formed and as a result of condensation forming a triglyceride molecule called?

Answer 23

Ester bonds (COCO)

Question 24

What do Ester bonds look like?

Answer 24

They are formed between a carbon in the glycerol molecule, the leftover oxygen atom and the carbon atom double bonded to the oxygen atom that did make up the carboxylic acid group before. COCO

Question 25

Are lipids polymers?

Answer 25

No

Question 26

How many fatty acids do phospholipids have?

Answer 26

2

Question 27

What are the main causes of heart disease?

Answer 27

Fatty deposits in coronary arteries (atheromas)

High blood pressure (hypertension)

Question 28

What is the disease of having atheromas?

Answer 28

atherosclerosis

Question 29

What factors contribute to heart disease? (4)

Answer 29

Diet high in saturated fats
Smoking
Lack of exercise
Aging

Question 30

Why does smoking contribute to heart disease?

Answer 30

It reduces the sizes of lumens

Question 31

Details in heart disease?

Answer 31

Kills 73000 in UK each year.

1in 6 men and 1 in 10 women die from coronary heart disease.

Question 32

How are lipoproteins formed?

Answer 32

After food has been absorbed at the small intestine, lipids and proteins combine to make lipoproteins. These are transported around the bloodstream in the blood.

Question 33

How many types of lipoproteins are there and what are they called ?

Answer 33

Low-density lipoproteins (LDLs)

high-density lipoproteins (HDLs)

Question 34

How are atheromas formed?

Answer 34

Ldls build up and cause an atheroma to form if the diet is high in saturated fat.

Question 35

How do atheromas cause heart disease?

Answer 35

An atheroma that forms in the coronary arteries can restrict blood flow to the heart muscle. This means that less oxygen and glucose is delivered to the cardiac muscle. This can result in angina and in serious cases, if the whole vessel gets blocked, a heart attack (myocardial infarction).

Question 36

How does a diet high in unsaturated fats affect the body and the risk of cardiovascular and coronary heart disease?

Answer 36

A diet high in unsaturated fats result in more hdls being produced. These carry unsaturated fats to the Liver for breakdown. The higher the ratio of hdl to LDL in a person’s blood, the lower the risk of cardiovascular and coronary heart disease.