1.2.9 - Lipids & Ester Bonds

Question 1

Describe Lipids
(3 Points)

Answer 1

~ Macromolecules that contain carbon, hydrogen and oxygen atoms.

~ Play an important role in energy storage, insulation and hormonal communication.

Features:
~ Non-polar, hydrophobic and insoluble.

Question 2

Describe Triglycerides
(3 Points)

Answer 2

~ Monomers are glycerol and fatty acids.

~ Made of one molecule of glycerol with 3 fatty acids attached to it.

~ Non-polar, hydrophobic and insoluble.

Question 3

Describe Fatty Acids

Answer 3

Contains a methyl group at one end of a hydrocarbon chain known as the R group, at the other end is a carboxyl group.

Question 4

How Do Fatty Acids Vary?
(2 Points)

Answer 4

~ Length of the hydrocarbon chain (R group).

~ Fatty acid chain may be unsaturated or saturated.

Question 5

Describe Saturated Fatty Acids
(4 Points)

Answer 5

~ Contain no carbon-carbon double bonds.

~ Hydrocarbon chain is saturated with hydrogen atoms, due to the absence of double bonds.

~ Form unbranched, linear chains.

~ Mainly found in animals fats. E.g. Butter.

Question 6

Describe Unsaturated Fatty Acids
(4 Points)

Answer 6

~ Contain carbon-carbon double bonds.

~ Causing the chain to kink, due to the double bonds.

~ Melt at lower temperatures than saturated fats.

~ Mostly found in plants. E.g. Olive oil.

Question 7

What Does A Diet High In Saturated Fats Increase Your Risk Of Developing?

Answer 7

CVD, as blood cholesterol levels increase.

Question 8

What Function Do Fats & Oils Have In Organisms?
(4 Points)

Answer 8

~ Energy storage.

~ Insulation.

~ Buoyancy.

~ Protection.

Question 9

How Are Triglycerides Formed?
(2 Points)

Answer 9

~ By condensation reactions.

~ 3 fatty acids and a single glycerol molecule are joined together by an ester bond.

Question 10

How Are Triglycerides Broken?
(2 Points)

Answer 10

~ By hydrolysis reactions

~ A molecule of water is added to each ester bond to break it apart, splitting up into 1 glycerol molecule and 3 fatty acids.

Question 11

How Is An Ester Bond Formed?
(4 Points)

Answer 11

~ When the hydroxyl (-OH) group from glycerol, bonds with the carboxyl group (-COOH) group of the fatty acid.

~ Formed during a condensation reaction, where for each ester bond formed a molecule of water is released.

~ 3 fatty acid then going to one glycerol to form a triglyceride.

~ For one triglyceride formed, 3 water molecules are released.