Unit 4 - Biological Molecules

Question 1

What are Carbohydrates needed for?

provides body with

Answer 1

Provide the body with glucose which is converted into energy to support bodily functions

Question 2

What elements are in carbohydrates ?

Answer 2

Carbon, Hydrogen, Oxygen

Question 3

What is the subunit of Carbohydrates

Answer 3

Sugar

Question 4

Example of carbohydrates as foods (simple and complex)

Answer 4

Simple : candy, Fruits
Complex: pasta, rice

Question 5

What is the food test for Starch and glucose ? What is a positive result?

Answer 5

Starch : Iodine test
Turns from Orange/ brown to Blue/ Black
Glucose : Benedicts test
Turns from blue to red

Question 6

What are proteins needed for?

Answer 6

Growth and repair

Question 7

Elements in protein

Answer 7

carbon, hydrogen, oxygen, nitrogen, sometimes sulfur

Question 8

What is the subunit of protein

Answer 8

amino acids

Question 9

Food example of protein

Answer 9

Fish , egg, meat

Question 10

What is the food test for proteins? What is a positive result?

Answer 10

biuret solution
From blue to purple

Question 11

What are lipids neeeded for?

Answer 11

Insulation and energy

Question 12

What elements are in lipids?

Answer 12

Carbon, oxygen, hydrogen

Question 13

What is the subunits of Lipids?

Answer 13

Glycerol and 3 fatty acids

Question 14

food example of lipids

Answer 14

Butter, cheese, meat

Question 15

What is the food test for lipids? what is a positive result?

Answer 15

Ethanol emulsion
Turns from clear to cloudy

Question 16

Steps : testing for starch

Answer 16

1. Put food sample on a spotting tile.
2. Add 2-3 drops of iodine solution.
3. Positive result for starch is if iodine turns from yellow to blue- black.

Question 17

Steps : testing for glucose

Answer 17

1. Place food sample into a boiling tube
2. Add an equal amount of benedicts solution.
3. Place boiling tube in a hot water bath
4. Positive test for glucose is if the solution turns from blue to red.

Question 18

Steps : testing for protein

Answer 18

1. Place food to be tested in a test tube.
2. Add 5-6 drops of biuret solution.
3. A positive result will turn from blue to purple.

Question 19

Steps : testing for vitamin C

Answer 19

1. Pipette 2cm^3 of DCPIP into a conical flask
2. Add the vitamin C solution to burette.
3. Add the solution drop by drop, shaking the conical flask each time.
4. Measure the volume needed for the indicator to change from blue to colorless.

Question 20

What is vitamin C needed for?

Answer 20

Tissue repair and disease resistance

Question 21

Food examples of Vitamin C

Answer 21

Oranges, Lemons, Limes

Question 22

State and describe the condition associated with a vitamin C deficiency:

Answer 22

Scurvy – the body tissue starts to break down. Usually starts in the gums, they start to bleed, and teeth fall out.

Question 23

What is the name given to the shape of DNA:

Answer 23

Double Helix

Question 24

What are the bases in DNA, and which one’s bond together?

Answer 24

A-T and C-G

Question 25

What is the role of water as a solvent in digestion?

Answer 25

Dissolves Enzymes and nutrients in the alimentary canal so digestion and absorption can occur

Question 26

What is the role of water as a solvent in excretion?

Answer 26

Urea, a harmful waste product, is dissolves in water (to make urea) so it can be easily removed from the body

Question 27

What is the role of water as a solvent in transport?

Answer 27

Blood plasma contains a lot of water. Allows substances dissolves in it such as glucose, to be easily transported around the body

Question 28

Why is amino acid sequence important in proteins?

Answer 28

determines protein shape.

Question 29

What does the shape of protein determine?

Answer 29

Protein function (what is does)

Question 30

How is shape important for enzymes ?

Answer 30

have a specific shape that fits just one type of molecule. Speed up the rate of reaction in our cells.

Question 31

How is shape important for Antibodies ?

Answer 31

have a specific shape to fit one type of bacteria or virus. Allows them to destroy these pathogens.

Question 32

How is shape important for haemoglobin?

Answer 32

has a specific shape to allow it to carry oxygen in red blood cells. These is needed by cells for respiration.

Question 33

Similarities between simple and complex carbohydrates

Answer 33

• Both are used for energy.
• Both have only carbon, Oxygen, and Hydrogen atoms

Question 34

Differences between simple and complex carbohydrates

Answer 34

• Simple carbs are soluble in water, but complex carbs are insoluble in water.
• Simple carbs are small (e.g., glucose). Complex ones are large, made of many simple carbs joined together (e.g., starch)

Question 35

Carbohydrates / glucose in plants

Answer 35

Plants transport sucrose, which is then converted into glucose before respiration

Question 36

Chains of glucose - made from (3)

Answer 36

1. cellulose - plants use to make cell walls
2. Starch plants use to store energy
3. glycogen - animals use to store energy in the liver

Question 37

DNA structure

4 ,bases, held together, back bone

Answer 37

• twisted ladder (double helix)
• back bone made of sugar and phosphate
• bases determine the code
• held together by hydrogen bonds