Module 2 Section 2 LIPIDS

Question 1

What are elements are lipids Made up of

Answer 1

Carbon Hydrogen oxygen

Question 2

What is the structure of a triglyceride

Answer 2

Glycerol head and 3 fatty acid tails

Question 3

What are the fatty acids long tails made of

Answer 3

Hydrocarbons

Question 4

Are fatty acid tails hydrophilic or hydrophobic

Answer 4

Hydrophobic (they repeal water)

Question 5

What is the basic structure of a fatty acid tail

Answer 5

O=C-R -> “R” varies
/
OH

Question 6

What happens in triglyceride synthesis

Answer 6

They are synthesised by the formation of an ester bond between each fatty acid and the glycerol molecule

Question 7

What is the process of triglyceride synthesis called

Answer 7

Esterification

Question 8

What type of reaction is Esterification

Answer 8

Condensation

Question 9

How do triglycerides break down

Answer 9

When ester bonds are broken

Question 10

What type of reaction is breaking up a triglyceride

Answer 10

Hydrolysis

Question 11

What’s the difference between saturated and unsaturated fatty acids

Answer 11

Saturated fatty acids have no double bonds between the carbon atoms, they are saturated with hydrogen

Unsaturated fatty acids have at least one double bond between carbon atoms

Question 12

What is the structural noticeable difference between saturated and unsaturated fatty acids

Answer 12

Unsaturated fatty acids have a kink caused by the double bond

Question 13

What is the structure of a phospholipid

Answer 13

They have a glycerol head, a phosphate group and two fatty acid chains

Question 14

What type of molecules are phospholipids made up of

Answer 14

Macromolecules

Question 15

What part of a phospholipid is hydrophilic

Answer 15

The phosphate group

Question 16

What part of a phospholipid is hydrophobic

Answer 16

The fatty acid tails

Question 17

Triglycerides are macromolecules. What are macromolecules?

Answer 17

Complex molecules with a relatively large molecular mass

Question 18

What is the function of triglycerides

Answer 18

Storage (energy in plants and animals, energy and carbon in some bacteria)

Question 19

How do the properties of triglycerides make them suitable for their functions

Answer 19

They have long hydrocarbon tails that contain lots of chemical energy, which is released when they are broken down, they can store about twice as much energy per gram as carbohydrates

They are insoluble so don’t allow water to enter cells by osmosis which would make them swell and reduce the amount of possible storage space

Question 20

What is the function of a phospholipid

Answer 20

Make up the phospholipid bilayer in cell membranes. Cell membranes control what enters and leaves a cell

Question 21

How do the properties of phospholipids make them suitable for their functions

Answer 21

Their heads are hydrophilic and tails are hydrophobic so they form a double layer with their heads facing out to the water on either side and protecting the tails inside
The centre of the bilayer is hydrophobic so water soluble substances can’t pass easily- the membrane acts as a barrier to those substances

Question 22

What is the function of cholesterol

Answer 22

In eukaryotic cells they strengthen the cell membrane by interacting with the phospholipid bilayer

Question 23

How do the properties of cholesterols make them suitable for their functions

Answer 23

It’s small in size and flat in shape

• allowing it to fit in between the phospholipid molecules in the membrane
• then they bind to the hydrophobic tails of the phospholipid causing them to pack more closely together
• making it less fluid and more rigid