Lipids 2.1.2 (h,i,j)

Question 1

What are lipids?

Answer 1

Fats and oils

Question 2

Are lipids polar?

Answer 2

No they are non-polar as the electrons are evenly distributed between the C, H and O.

This makes them insoluble in water.

Question 3

What is a macromolecule?

Answer 3

Molecules made from repeating units such as polysaccharides

Lipids are macromolecules

Question 4

What is a triglyceride made out of?

Answer 4

1 glycerol ——> alcohol

3 fatty acids ——-> carboxylic acid

Question 5

What bonds are created between the glycerol and fatty acids in a triglyceride?

Answer 5

Both molecules contain an OH functional group. They both interact with each other to form an ester bond.

This reaction is called esterification which is a condensation reaction.

Therefore water is a product of esterification.

Question 6

How are ester bonds broken?

Answer 6

Water molecules are needed to reverse the reaction. This process is called hydrolysis

Question 7

What is a saturated fatty acid?

Answer 7

A fatty acid with NO DOUBLE BONDS
this is because all the carbon atoms form the maximum number of bonds with hydrogen atoms

Question 8

What is an unsaturated fatty acid?

Answer 8

A fatty acid with ONE OR MORE DOUBLE BONDS

Question 9

What do the double bonds do to the structure of an unsaturated fatty acid?

Answer 9

The molecules are able to kink/bend when there is a double bond (because it changes the angle of the bond)

This stops unsaturated fats from packing close together.

Question 10

Why are unsaturated fats liquid at room temperature?

Answer 10

Because of the kink in their structure, they cannot be closely packed together which means that they remain liquid at room temperature.

Question 11

Which fat is healthy?

Answer 11

Unsaturated

Question 12

Which fat is unhealthy?

Answer 12

Saturated because an excess could lead to coronary heart disease

Question 13

What is phospholipid?

Answer 13

Modified triglycerides which contain CHO as well as a phosphate group

Question 14

Are phospholipids charged?

Answer 14

Yes they have extra electrons which makes the negatively charged which makes them SOLUBLE IN WATER

Question 15

What is different about the structure of a phospholipid from a triglyceride?

Answer 15

A fatty acid chain is replaced by a phosphate group

Question 16

Phospholipids properties?

Answer 16

• Hydrophobic tails
  they are NON-POLAR which means that they REPEL water
• Hydrophilic heads
  they are POLAR and therefore ATTRACT water molecules

Question 17

Phospholipid function?

Answer 17

The cell membrane in a cell contains a phospholipid bilayer (which is made up of phospholipids). They have the hydrophilic heads in the water and the hydrophobic tails facing inwards. This allows them to separate conditions inside and outside a cell.

Question 18

What is cholesterol?

Answer 18

It provides structure to the cell membrane by maintaining fluidity to the cell.

they bind to fatty acid tail to pack them closer to each other

Question 19

Where is it found?

Answer 19

In the cell membrane, wedged in between the phospholipid fatty acid tails

Question 20

What is cholesterols structure?

Answer 20

It contains an OH group which is charged and therefore hydrophilic

Question 21

role of lipids?

Answer 21

membrane formation
hormones
electrical insulation
waterproofing
thermal insulation
buoyancy