LIPIDS

Question 1

What are the types of lipids? (2)

Answer 1

-triglycerides
-phospholipids

Question 2

How are triglycerides formed? (1)

Answer 2

During a condensation reaction with glycerol and three fatty acids.

Question 3

What is glycerol? (1)

Answer 3

An alcohol.

Question 4

What are the bonds formed between a glycerol and three fatty acids called? (1)

Answer 4

Ester bonds.

Question 5

How long are fatty acid chains? (1)

Answer 5

Between 14 and 22 carbon atoms long

Question 6

What is triglycerides in terms of its water properties? (1)

Answer 6

Hydrophobic.

Question 7

Why is triglyceride hydrophobic? (1)

Answer 7

Because of the hydrocarbon chains of the component fatty acids.

Question 8

Where in a triglyceride does a condensation reaction happen, and where does the bond for? (2)

Answer 8

A bond is formed between the carboxyl group (-COOH) of fatty acid and one of the hydroxyl groups (-OH) of glycerol to produce monoglyceride.

Question 9

What happens after the formation of monoglyceride? (1)

Answer 9

Condensation reaction is repeated to give a diglyceride.

Question 10

What happens after the formation of a diglyceride? (1)

Answer 10

Condensation reaction repeats to form a triglyceride.

Question 11

What are the types of fatty acid chains? (2)

Answer 11

-saturated fatty acid chains
-unsaturated fatty acid chains

Question 12

What are the types of unsaturated fatty acid chains? (2)

Answer 12

-trans-unsaturated fatty acids
-cis-unsaturated fatty acids

Question 13

What is a saturated fatty acid? (1)

Answer 13

One in which all the bonds between carbon atoms in the hydrocarbon chain are single covalent bonds.

Question 14

What are unsaturated fatty acids? (1)

Answer 14

A fatty acid in which one or more pairs of adjacent carbon atoms in the hydrocarbon chain are linked by a double covalent bond.

Question 15

If an unsaturated fatty acid has one double bond what is it called? (1)

Answer 15

A monounsaturated fatty acid.

Question 16

If an unsaturated fatty acid has more than one double bond what is it called? (1)

Answer 16

A polyunsaturated fatty acid.

Question 17

Why do unsaturated fatty acids have low melting points? (2)

Answer 17

Because they can’t pack close due to the kinks in the chains caused by the double bonds which makes them solid at room temperature.

Question 18

What are trans-unsaturated fatty acids? (2)

Answer 18

-H atoms are opposite on chain
-natural therefore healthier

Question 19

What are cis-unsaturated fatty acids? (2)

Answer 19

-H atoms are on the same side of the chain.
-are processed therefore are unhealthier (more like saturated fatty acid)

Question 20

What is a phospholipid? (2)

Answer 20

Has a phosphate group, a glycerol and two fatty acids acid chains.

Question 21

What makes a phospholipid both hydrophilic and hydrophobic? (2)

Answer 21

The phosphate head (compose of Botha phosphate group and a glycerol) are hydrophilic and thee fatty acid tails are hydrophobic.

Question 22

What is a phospholipid in terms of water properties? (1)

Answer 22

Is both hydrophilic and hydrophobic.

Question 23

What is a bilayer (1)

Answer 23

A single structure made of two layers of molecules usually used to describe the arrangement of phospholipids in a cell membrane.