1. the Diagram Represents the Process by Which Green Plants Make Glucose

Name ................................................ Homework 3.1

Date due ..........................................

1. The diagram represents the process by which green plants make glucose.

a) Name the process. ……………………………………………………………………………………………………….. 1

b) Name gases X and Y X …………………………………………………………………………………………………… 1

Y ………………………………………………………………………………..………………… 1

c) Sunlight is essential for this process. Name the substance in green plants which can

absorb sunlight. ………………………………………………………………………………………………………. 1

2. The diagram represents the processes by which energy is produced in humans.

a) Name the process. ………………………………………………………………………………………………………….. 1

b) Name gases X and Y X ……………………………………………………………………………………………………… 1

Y ……………………………………………………………………………………………………… 1

3. Over the past two centuries the amount of carbon dioxide in the atmosphere has been

increasing.

a) Give two reasons for this rise ………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………..

…………………………………………………………………………………………………………………………………………..…………….. 2

b) What name is given to this rise in world wide atmospheric temperature rise?

……………………………………………………………………………………………………………………………………………………………… 1

Homework 3.1

4. A student set up the apparatus shown below to investigate the rate of photosynthesis.

Oxygen gas produced by the plant was collected in the test tube

a) What effect does the distance of the lamp from the plant have on the number o

bubbles of oxygen gas produced?

………………………………………………………………………………………………………………………………………………………………

……………………………………………………………………………………………………………………………………………………………… 1

b) Give one variable that needs to be kept the same to make the experiment fair.

……………………………………………………………………………………………………………………………………………………………… 1

5. The diagram below shows a molecule of the carbohydrate, glucose.

CH2OH CH2OH H

C O C C

C C CH2OH

C C

What is the formula for glucose? ………………………………………… 1

6. a) Describe the chemical test for oxygen ………………………………………………………………………………. 1

b) Describe the chemical test for carbon dioxide ……………………………………………………………….. 1

Name ................................................ Homework 3.2

Date due ..........................................

1. Farmers use herbicides to kill weeds.

The diagram shows a molecule of a herbicide.

a) Complete the formula to show the number of each type of atom in this molecule.

C…... H….…O…… N……. P……. 1

b) Why does a crop not grow as well when there are lots of weeds growing in beside

the crop?

…………………………………………………………………………………………………………………………………………………………… 1

c) What name is given to the type of chemicals used to

i) kill pests such as slugs and insects which eat crops? ………………………………………………….. 1

ii) kill bacteria and fungi which cause plants to become diseased? ……………………………….. 1

2. Instead of using chemicals to kill pests farmers can encourage the use of

use of natural predators to eat the pests.

Name an animal that is used to keep down the number of greenfly on plants.

…………………………………………………………………………………………………………………………………………………………… 1

3. Plants require essential elements and each element has a different function in the plant.

Nitrogen is needed for root development and leaf growth. The rate of plant growth is

improved by the element potassium, while the element phosphorus controls leaf

development and size.

Present all the information in the passage as a table with two suitable headings.

Homework 3.2

4. Name a natural fertiliser …………………………………………………………………………………. 1

5. A farmer wishes to add the essential element phosphorus to his crops. He decides to

use a phosphate compound. He has available both sodium phosphate and calcium

phosphate. Using page 4 of the data book to help you, decide which one he should use

and give your reason.

The farmer should use ……………………………………………. because it is ……………………………………………

…………………………………………………………………………………………………………………………………………………………….. 2

6. The graph below shows the percentage of nitrogen (N), phosphorus (P) and

potassium (K) present in a bags of Bestgrow and Wondercrop fertilisers.

a) Which fertiliser

i) contains 11% potassium? ………………………………………….... 1

ii) contains a higher percentage of phosphorus than nitrogen? …………………………………..…….. 1

b) What is the percentage of phosphorus in Bestgrow? ……………………………………… % 1

7. Name two types of plant which have root nodules which can convert nitrogen in the

air into nitrate fertiliser in the soil.

…………………………………………………….. and ……………………………………………………………… 2

Homework 3.2

8. The pie chart shows the percentage of nitric acid used to make other substances

a) What percentage of nitric acid is used to make nylon? ……………………………… 1

b) 20 million tonnes of nitric acid are produced in Europe each year.

How many million tonnes of nitric acid are used to make fertilisers?

………………… million tonnes 1

c) Nitric acid is used to make the fertiliser ammonium nitrate.

Name the element provided by ammonium nitrate which is essential for healthy

plant growth?

…………………………………………….……. 1

9. The graph shows how fertiliser use is changing.

a) Why is the amount of fertiliser used changing in this way? ………………………………………….

…………………………………………………………………………………………………………………………………………………………… 1

b) What has been the increase in use of fertiliser from 1980 to 1990?

……………… million tonnes 1

Name ................................................ Homework 3.3

Date due ..........................................

1. a) Name the four main elements in the human body?

……………………………………………………………………………………………………………………………………………………………… 2

b) What is the most common compound in the human body?

……………………………………………………………………………………………………………………………………………………………… 1

2. There are three types of essential compounds which make up a healthy diet.

One of these essential compounds is carbohydrates.

Name the other two essential compounds in our diet.

………………………………………………………………and…………………………………………………………………………………… 2

3. Minerals supply the body with small amount of essential elements.

Two of the essential elements are calcium and iron.

a) Why do we need calcium in our diet? .................................................................................

b) Why do we need iron in our diet? ....................................................................................... 2

4. The body needs a constant supply of small amount of minerals in order for it

to function properly. Selenium which can be obtained from grain prevents the

breakdown of body fats. Tea is a good source of fluorine which is needed for decay

resistant teeth. Nerve transmission in the body relies on a supply of potassium.

Bananas are a good source of potassium. Green vegetables supply many minerals

among them magnesium which is needed for making body proteins.

Present all of this information in the form of a table with three suitable headings.

Homework 3.3

5. What percentage of the body weight is water?

A less than 25%

B About 45%

C About 50%

D mote than 60%

Underline the correct answer. 1

6. Vitamins are needed to keep a body healthy.

Vitamin A is used to fight disease. Vitamin D is needed for bone development.

Both vitamin C and vitamin E are found in green vegetables.

Vitamins

in fish

needed for needed for needed for

healthy skin reproduction bone development

vitamin E vitamin A

a) Use the information given to complete the key. 2

b) Apart from vitamin A, what other vitamin is found in fish? Vitamin ........................... 1

7. A sample of cows milk was found to contain 88% water.

Calculate the mass of water in 200g of cows milk.

……………………………….. 1

Name ................................................ Homework 3.4

Date due ..........................................

1. The grid below shows some carbohydrates.

A glucose

B starch

C maltose

D fructose

E sucrose

Which box(es) shows

a) a carbohydrate that is a polymer molecule?

Box letter ........................... 1

b) the two carbohydrates that do not react with Benedict’s solution?

Boxes ...................... and .......................... 1

c) the carbohydrate which green plants join together to form starch.

Box letter .......................... 1

d) the carbohydrate which turn blue-black with iodine solution.

Box letter .......................... 1

e) the carbohydrate which is nearly insoluble in water and has no taste?

Box letter ....................... 1.

2. A carbon and hydrogen

B carbon hydrogen, oxygen and nitrogen

C carbon, hydrogen and oxygen

D carbon, oxygen and nitrogen

Which box in the grid above shows the elements present in all carbohydrates?

Box letter ................. 1

3. What are carbohydrates used for in the body? .................................................................

........................................................................................................................................................... 1

4. Complete the following sentences by filling in the blank spaces.

During digestion starch molecules is broken down into ................................... molecules.

The digestion of starch molecules is brought about by the action of the enzyme,

........................................ found in saliva and by the action of ..............................................

acid found in the stomach. 3

Homework 3.4

5. A class was investigating the breakdown of starch using the enzyme found in

saliva.

They carried out the experiments at different pH values and timed how long it took

for the starch to be completely broken down.

Their results are shown in the table below.

pH Time taken (minutes)

5.5 6.0

6.0 5.5

6.5 4.0

7.0 1.8

7.5 2.5

8.0 3.5

8.5 4.0

a) Plot a line graph of the results shown in the table – the x axis has already been

done for you.

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 2

b) Predict how many minutes it would take for the breakdown of the starch when the

pH value is 9.0. .................... minutes 1

c) Does the enzymes work best in acid, alkali or neutral solutions? ............................... 1

d) The enzyme is a catalyst which works in the body. What does a catalyst do? ...................................................................................................................................................................... 1

Name ................................................ Homework 3.5

Date due ..........................................

1. How does the amount of energy released from one gram of fat compare with

that released by one gram of carbohydrate?

...............................................................................................................................................................

............................................................................................................................................................... 1

2. Using the information given on page 7 of the data booklet draw a bar graph

of the mass of fat in grams per 100g of food for the following foods:-

steak sausages cheese eggs

3. Using the information on page 7 of the data booklet calculate

a) the mass of fat present in 50g of butter.

................. g 1

b) the mass of fat in 100g of steak + 100g of eggs

.................. g 1

4. Why do many doctors suggest that we replace saturated fats in our diet

with foods which contain polyunsaturated fats instead?

..............................................................................................................................................................

................................................................................................................................................................... 2

5. Describe a test which you could carry out to show that butter contains fat.

..............................................................................................................................................................

................................................................................................................................................................... 1

Homework 3.5

6. A piece of cheese was put in a test tube. Some soda lime was added.

The mixture was then heated. The gas coming out of the test tube was

tested using damp pH paper.

Draw and label a diagram of this experiment.

7. The table below gives some information about 4 different foods.

Food carbohydrate fat energy

(g per 100g) (g per 100g) (kJ per 100g)

Butter 0.1 81.5 3000

Crisps 30.5 12.0 2050

Peanuts 7.8 53.0 2600

Bread 45.9 0.8 970

a) Which of the foods produces the least amount of energy per gram? ………………….……….. 1

b) How much fat is there in a packet of crisps which contains 25g of crisps?

……………….. g 1

c) How many grams of butter would provide 600 kJ of energy?

…………………. g 1

d) How much more energy of provided by 100g of butter than 100g of peanuts?

…………………… kJ 1

e) How many grams of carbohydrate are there in a 200g packet of peanuts?

…………………… g 1

Name ................................................ Homework 3.6

Date due ..........................................

1. A Balanced Diet

Type of food Why it is needed

Carbohydrates Provides energy

Proteins .................................................................

Vitamins and minerals For healthy skin, teeth and bones

...................................... Keeps the gut working properly

Complete the table by filling in the missing information 2

2. Food additives are chemicals added to food.

a) Potassium sorbate is added to fruit juice as a preservative.

Why is a preservative added?

.............................................................................................................................................................

............................................................................................................................................................. 1

b) The label below shows the ingredients in a fruit juice.

Ingredients:- apple juice, blackcurrent juice, citric acid,

anthocyanins, flavourings, vitamin C, potassium sorbate

From this list of ingredients name another additive in the fruit juice and

say why it is used.

.............................................................................................................................................................

............................................................................................................................................................. 1

3. a) Complete the following sentence

All protein molecules contain the elements carbon, hydrogen, oxygen and

............................................................... 1

b) A sample of protein is mixed with soda lime and the mixture heated in a test

tube. A piece of damp pH paper is held at the mouth of the test tube.

What would happen to the pH paper? ..................................................................................... 1

Homework 3.6

4. The results of tests carried out on a piece of food are shown in the table.

Food test Result

Food rubbed on filter paper Greasy mark

Benedict’s test Stays blue

Iodine test Turns blue-black

Heated with soda lime No gas produced

Which two types of food were present in this piece of food?

............................................. and .................................................................. 2

5. Which type of food produces amino acids during digestion?

A Oils

B Fats

C Proteins

D Carbohydrates

Underline the correct answer. 1

6. a) Name two sources of fibre in the diet of humans.

................................................................and......................................................................................... 2

b) What happens to fibre in the gut when it absorbs water?

............................................................................................................................................................. 1

7. Scurvy is a disease cause by a vitamin deficiency.

A deficiency of which vitamin will lead to scurvy

A Vitamin A

B Vitamin B

C Vitamin C

D Vitamin D

Underline the correct answer. 1

8. Which element is present in proteins but not present in carbohydrates?

............................................................... 1

9. What is a person likely to suffer from if their diet does not contain enough fibre?

............................................................... 1

Homework 3.6

10. The pie chart shows the percentage of phosphoric acid used to make other substances.

a) Give one reason why a food might contain a food additive. ……………………………………………….

………………………………………………………………………………………………………………………………………………………….. 1

b) 50 million tonnes of phosphoric acid are used each year.

Calculate the mass of phosphoric acid used to make food additives each year.

………………… million tonnes 2

11. In the European Union food additives are identified by an E number.

E-100 is the compound curcumin which is a yellow food colour. The food preservative,

Sorbic acid has the E number E 200. Vitamin C has the E number E 300 and is an

anti-oxidant.

Present this information as a table with three headings.

Name ................................................ Homework 3.7

Date due ..........................................

1. Alcohol can be made from carbohydrates.

Which substance catalyses the reaction?

A Ethanol

B Yeast

C Ethanol

D Carbon dioxide

Underline the correct answer. 1

2. Which of the drinks shown below contains a single unit of alcohol.

A a pint of beer

B a large whisky

C a bottle of alcopop

D a single glass of wine

Underline the correct answer. 1

3. What name is given to the chemical process in which glucose is converted into

ethanol?

...................................................... 1

4. How long does it take the body to break down the alcohol in one pint of beer?

............................................. 1

5. A bottle 200ml of cider. The alcohol concentration in the cider is 8%.