Biological Molecules (carbohydrates&lipids) 2.1

Question 1

What are carbohydrates?

Answer 1

Organic compounds

Question 2

What do carbohydrates contain?

Answer 2

• hydrogen
• oxygen
• carbon

Question 3

What is the general formula for carbohydrates?

Answer 3

Cn(H2O)n

Question 4

Draw alpha glucose (label the carbons)

Answer 4

Picture online

Question 5

Draw beta glucose

Answer 5

Picture online

Question 6

What is hydrolysis?

Answer 6

When water is added to a molecule and break 1 or more bonds within it

Question 7

Draw 2 alpha glucose molecules joined by a the addition of water

Answer 7

Picture online

Question 8

What is a condensation reaction?

Answer 8

When water is produced due to a chemical reaction

Question 9

What bond is formed during condensation of 2 types of sugar molecules?

Answer 9

Glycosidic

Question 10

Name 3 sources of lipids

Answer 10

• dairy
• sat fats eg meat
• un-sat fats eg olive oil

Question 11

What are the functions of lipids?

Answer 11

• insulation
• production of hormones
• phospholipid bilayer
• water proofing

Question 12

Name the 4 types of lipids and give an example where possible

Answer 12

• waxes eg fatty acids
• steroids eg hormones
• triglycerides
• phospholipids

Question 13

Draw a glycerol molecule

Answer 13

H
          |
H— C—O—H
          |
H— C—O—H
          |
H— C—O—H
          |
         H

Question 14

Draw a fatty acid

Answer 14

O H H H H H
\ | | | | |
C—C—C—C—C—C—H
// | | | | |
HO H H H H H
(No H bonded to end H in chain, format error)

Question 15

How many fatty acids are in a triglyceride?

Answer 15

3

Question 16

What bond forms between a glycerol and fatty acid molecule?

Answer 16

An Easter bond

Question 17

What type of reaction takes place when joining a glycerol and fatty Vaud molecule?

Answer 17

Condensation reaction

Question 18

What are the characteristics of saturated fats?

Answer 18

• all available carbon bonds filled with hydrogen
• single carbon bonds only
• molecules can pack closely together
• high surface area
• high boiling and melting point

Question 19

What does mono-saturated mean?

Answer 19

One double carbon bond

Question 20

What are the characteristics of a polyunsaturated fatty acid?

Answer 20

• more than one double carbon bond
• several hydrogen missing
• molecules aren’t packed closely together
• lower surface area
• lower melting and boiling point (less energy to break bonds)

Question 21

Draw a phospholipid

Answer 21

O H
| |
O—P—O—C—H O
|| | ||
O H—C—O—C—CH2—CH2—CH2—CH3
| O
| ||
H—C—O—C—CH2—CH2—CH2—CH3
|
H

Question 22

What can reducing sugars do?

Answer 22

Give electrons to other molecules

Question 23

What is the test for reducing sugars?

Answer 23

• heat with Benedictus solution

- orange/red/yellow/green indicates reducing sugar

Question 24

What is a precipitate?

Answer 24

Comes from solution, solid suspended in a liquid

Question 25

What is the test for carbohydrates?

Answer 25

- add iodine to sample | - choir change from yellow to blue/black

Question 26

What is the test for non-reducing sugars?

Answer 26

- test to make sure there are no reducing sugars - boil sample with hydrochloric acid - cool and add hydrocarbonate - test for reducing sugars again

Question 27

What is the test for lipids?

Answer 27

- mix sample with ethanol - filter - pout solution into test tube with water - cloudy emulsion indicates lipids are present

Question 28

What is the test for proteins?

Answer 28

- use biuret | - lilac indicates proteins are present