Nutrition and Living Organisms

Question 1

What are heterotrophic animals?

Answer 1

They are animals that feed by eating (feeding of others)

Question 2

How many types of heterotrophic animals are there? What are they?

Answer 2

There are 5 types:

1. Herbivores - only eat plants
2. Carnivores - only eat meat
3. Omnivores - eats both plants and meat
4. Parasites - live and feed on other living things
5. Saprophytes - grow on dead and decaying matter

Question 3

Give an example of a:

a) Herbivore
b) Carnivore
c) Omnivore
d) Parasite
e) Saprophyte

Answer 3

a) Rabbit, snail
b) Tiger, snake
c) Hedgehog, parrot
d) Fleas
e) Mould, yeast

Question 4

How do plants get nutrition?

Answer 4

They feed by making their own food using photosynthesis. They are AUTOTROPHIC (self-feeding).

Question 5

What do plants need to grow?

Answer 5

They need light (sunlight), water (rain), and carbon dioxide.

Question 6

What is the word equation for photosynthesis?

Answer 6

Carbon dioxide + water —-> Glucose + oxygen

Question 7

What is the symbol equation for photosynthesis?

Answer 7

6CO₂ + 6H₂O —-> C₆H₁₂O₆ + 6O₂

Question 8

What are the 7 food groups?

Answer 8

Fats
Carbs
Protein 
Fibre
Vitamins
Minerals
Water

Question 9

What is a balanced diet?

Answer 9

A balanced diet is one that contains all of the 7 food groups in the corrects amounts that are appropriate to your needs.

Question 10

What do proteins do?

Answer 10

The make new cells during growth and they repair old or damaged cells.

Question 11

What are proteins made of?

Answer 11

They are made of amino acids, there are 20 different types of amino acids which make up proteins. (learn diagram)

Question 12

Give some examples of foods that have high protein content.

Answer 12

Beans,
Meats,
Eggs,
Nuts,
Fish etc.

Question 13

What do fats do?

Answer 13

Fats give us energy, they contain a lot more energy than the same amount of carbs. We need fats as an energy store. Fats also act as an insulator and stop our body from losing too much heat.

Question 14

What are fats made of?

Answer 14

Glycerol and 3 fatty acids (learn diagram)

Question 15

Foods rich in fat are…

Answer 15

Cakes
Butter
Fried foods
Cheese
Crisp
Pastry
Doughnuts etc.

Question 16

What are sugars and what do they do?

Answer 16

Sugars are carbs that give us energy, they are the fuel that we need to stay alive.

Question 17

What is the most important sugar that our body uses?

Answer 17

Glucose.

Question 18

Name 3 other sugars (not glucose)

Answer 18

Fructose (fruit sugar)
Lactose (milk sugar)
Maltose (found in cereals)

Question 19

What is the sugar we put in our tea?

Answer 19

It is a disaccharide of glucose and fructose called sucrose.

Question 20

What is starch made of?

Answer 20

Starch is a carb made of lots of small glucose molecules.

Question 21

What foods are rich in starch?

Answer 21

Bread
Rice
Pasta etc.

Question 22

What is the food test for starch?
What is the positive result?
What is the negative result?

Answer 22

Put a couple of drops of iodine solution into a spotting tile with the substance being tested.
Positive = Blue/Black
Negative = Orange/Brown

Question 23

What is the food test for protein?
What is the positive result?
What is the negative result?

Answer 23

Put the substance being tested and some sodium hydroxide into a test tube with copper sulfate. Mix this around and wait for the results.
Positive = Purple
Negative = Blue

Question 24

What is the food test for glucose (reducing sugar)?
What is the positive result?
What is the negative result?

Answer 24

Put some benedicts solution and the substance being tested into a boiling tube and mix it around. Boil it in a water bath for around 10 mins.
Positive = Brick red
Negative = Blue

Question 25

What is the food test for fats?
What is the positive result?
What is the negative result?

Answer 25

Put the substance being tested into a test tube with some ethanol, mix this, then add some water, mix again.
Positive = Cloudy, white emulsion
Negative = Clear, colourless solution

Question 26

How do find the amount of energy per g of a substance (eg.crisp) (using water temp etc.)

Answer 26

To find the energy per g of crisp:
Burn some crisp holding underneath a boiling tube of water, measure the temperature change of the water using a thermometer.
Use this equation to work out the energy in 1g of crisp:
1) Amount of water x 4.2 x temp rise of water = energy in crisp (J)
2) energy in crisp (J) ÷ mass of crisp (g) = energy per g.

Question 27

Why is this not the most effective way to find the energy per g in a crisp?

Answer 27

Because the energy isn’t going directly to the water, some might go into the air. Some of the energy might also go into different methods of energy release such as light or sound energy.