Lipids

Question 1

What can lipids dissolve in?

Answer 1

Organic solvents like ethanol

Question 2

What makes up a triglyceride?

Answer 2

One glycerol molecule and three fatty acid chains

Question 3

What are the bonds called in a triglyceride and phospholipid?

Answer 3

Ester bonds

Question 4

What is the difference between triglycerides and phospholipids?

Answer 4

phospholipids have a phosphate group that replaces one fatty acid chain

Question 5

What is so special about phospholipids structure?

Answer 5

It has a hydrophilic head and a hydrophobic end so it can form membranes

Question 6

What is another name for a condensation reaction?

Answer 6

Esterification

Question 7

What is meant by saturated?

Answer 7

Fatty acid chains with no double bonds

Question 8

Name 4 roles of lipids?

Answer 8

Cushioning against knocks.

Buoyancy for aquatic mammals.

Thermal insulation against heat loss.

Waterproofing on surfaces.

Question 9

Phospholipids form what type of membranes?

Answer 9

Unilayer or bilayer.

Question 10

What element, as well as carbon, hydrogen and oxygen, is present in a phospholipid?

Answer 10

Phosphorus

Question 11

What element do lipids have a lower proportion of in their structure than carbohydrates have?

Answer 11

Oxygen

Question 12

Why is it that lipids are used in a variety of ways by organisms?

Answer 12

They have a wide range of molecular structures, functions and properties.

Question 13

What are the two most common lipids?

Answer 13

Triglycerides and Phospholipids.

Question 14

What is the name of a fatty acid with one double bond in its structure?

Answer 14

Monounsaturated

Question 15

What are phospholipids?

Answer 15

Modified triglycerides.

Question 16

Which end of a phospholipid is hydrophilic?

Answer 16

phosphate head/charged head.

Question 17

What are sterols/steroid alcohols?

Answer 17

They are a type of lipid but they are not fats or oils

Question 18

Give an example of a sterol.

Answer 18

cholesterol

Question 19

Where is cholesterol made and where can it be found?

Answer 19

Made in the liver and intestine. Found in between phospholipids of the cell membrane.

Question 20

What are the functions of cholesterol?

Answer 20

Adds stability to the cell membranes.

Maintains fluidity of membranes. Keeps them fluid at low temperatures. Stops them becoming too fluid at high temperatures.

Question 21

draw a glycerol molecule

Answer 21

Question 22

Draw a fatty acid

Answer 22

Question 23

Why are phospholipids called surface active agents or surfactants?

Answer 23

The way that they react with water in a dual nature means they are surfactants.