Topic 5 - Biological Molecules

Question 1

What is the function of Carbohydrates?

Answer 1

Gives you quick energy

Question 2

What is the definition of Lipids?

Answer 2

For insulation and a sources of slow energy release

Question 3

What is the definition of Protein?

Answer 3

For growth

Question 4

What is the definition of Dietary fiber?

Answer 4

Supports healthy digestion and movement of food through alimentary canal (peristalsis)

Question 5

What are the 3 types of vitamins and their purpose?

Answer 5

Vit A for eyesight and skin health, Vit C for healing wounds and strengthening connective tissues, Vit D for bone health

Question 6

What are the 2 types of Minerals and their purpose? (2)

Answer 6

Calcium for bone health, Iron to produce haemoglobin (in red blood cells)

Question 7

What is the definition of Water?

Answer 7

To maintain osmotic pressure in cells

Question 8

What are the 3 types of Polymer? (3)

Answer 8

Carbohydrates, protein, lipids (fats & oils)

Question 9

What are the 3 types of Monomer?

Answer 9

Glucose, amino acid, fatty acids/glycerol

Question 10

What is the energy experiment in dry food?

Answer 10

Dry foods can be burned and used to heat water to measure the amount of energy released. This experiment isn’t also that accurtue because of the energy released to the environment but can be improved using insulation.

Question 11

What is the testing reagent for starch and what is it called?

Answer 11

Testing reagent: iodine - Positive result: colour change from orange-brown to blue-black

Question 12

What is the testing reagent for Glucose and what is it called?

Answer 12

Testing reagent: benedict’s - Positive result: colour change from blue to orange-red

Question 13

What is the testing reagent for Lipids and what is it called?

Answer 13

Testing reagent: ethanol - Positive result: cloudy emulsion forms

Question 14

What is the testing reagent for Protein and what is it called?

Answer 14

Testing reagent: biuret - Positive result: colour change from blue to purple

Question 15

What is a Calorimetry?

Answer 15

Measuring the amount of heat released or absorbed during a chemical reaction.

Question 16

What is nutrients?

Answer 16

A molecule found in food which has a specific role in the body essential to life and growth.

Question 17

Monomer definition?

Answer 17

A small, individual molecule

Question 18

Polymer definition?

Answer 18

Large molecules made up of many monomers.

Question 19

What is reagent?

Answer 19

A substance used in chemical analysis or other reactions

Question 20

Why do humans require energy?

Answer 20

Humans, and other organisms, require energy for: Maintaining body temperature, Making new molecules, Movement (and other life processes!)

Question 21

How much energy do humans require?

Answer 21

Dependent on their lifestyle, people will require different amounts of energy and will, therefore, eat different amounts and types of food. These requirements can be affected by age, activity levels, metabolism and factors like pregnancy

Question 22

What is the energy equation?

Answer 22

Energy (joules per gram) = difference in temp x mass of water x 4.2 joules ÷mass of food (g)

Question 23

What is the test for starch? (2)

Answer 23

1. Put a small sample of the first food onto a white tile. Add a few drops of iodine solution.
2. Record your results and conclusion in your table

Question 24

What is the test for sugar? (3)

Answer 24

1. Put a small sample of the first food into a boiling tube. Add about 3 cm depth of Benedict’s solution and mix it with the food
2. Stand the tube in a very hot water bath and leave it for about 5 min.
3. Record the results in the table below

Question 25

What is the test for protein? (3)

Answer 25

1. Chop up or crush a small sample of the first food, and put it into a test tube
2. Add about 3 cm depth of biuret solution. Shake the tube or stir with a clean glass rod, to mix the food and biuret solution
3. Record you results in the table

Question 26

Benedicts Results

Answer 26

No sugar = blue
Very little sugar = green
Little sugar = yellow
Medium sugar = orange
High sugar = red

Question 27

What is the test for Fats? (4)

Answer 27

1. Chop or crush a sample of the first food and put it into a very clean dry test tube
2. Add enough ethanol to cover the food. Shake the or stir with a clean glass rod to mix the food and ethanol
3. Put some water into another clean test tube. Carefully pour some of the ethanol in the tube with food (don’t pour the food only the solution) into the water.
4. Record your results in the table