B3 - Organisation and the digestive system

Question 1

What are cells?

Answer 1

The basic building blocks of all living organisms.

Question 2

What is a tissue?

Answer 2

A group of cells with a similar structure and function.

Question 3

What is an organ?

Answer 3

Aggregations of tissues performing specific functions.

Question 4

What is an organ system?

Answer 4

A group organs which work together to form organisms.

Question 5

What is a muscular tissue?

Answer 5

A tissue that contracts to move whatever it’s attached to.

Question 6

What is a glandular tissue?

Answer 6

A tissue which makes and secretes chemicals like enzymes and hormones.

Question 7

What is an epithelial tissue?

Answer 7

A tissue which covers some parts of the body.

Question 8

What is the order in which food passes through the digestive system?

Answer 8

Mouth > oesophagus > stomach > small intestine > large intestine > rectum >anus

Question 9

What is the function of the mouth in digestion?

Answer 9

To mechanically break up food into smaller pieces to increase surface area.

Question 10

What are two functions of saliva in digestion?

Answer 10

To moisten food to allow easier swallowing.

To start chemical digestion by containing salivary amylase.

Question 11

What is the function of stomach acid?

Answer 11

To kill potentially pathogenic microorganisms in food.

Question 12

What is the function of the small intestine?

Answer 12

To absorb glucose, amino acids vitamins and mineral ions digested in food.

Question 13

How are the small intestines adapted to carry out their function?

Answer 13

They have structures called villi which increase surface area.

Question 14

How are villi adapted to increase absorption?

Answer 14

Large surface area, wall is only one cell thick and large blood supply.

Question 15

What is the function of the large intestine?

Answer 15

To absorb water from digested food.

Question 16

What is the function of the liver in digestion?

Answer 16

To produce bile.

Question 17

What is the function of the gall bladder?

Answer 17

To store bile until it can be released into the small intestine.

Question 18

What is the function of bile?

Answer 18

Neutralises hydrochloric acid from the stomach.

Emulsifies fats to increase their surface area.

Question 19

What is the function of the rectum?

Answer 19

To store undigested material before excretion.

Question 20

What are the products of digestion used for?

Answer 20

Build new carbohydrates, lipids and proteins.

Glucose is used for respiration.

Question 21

What practical steps are needed for when testing for food molecules present in different foods?

Answer 21

1. Break the food up using a pestle and mortar.
2. Transfer to a beaker and add some distilled water.
3. Stir the mixture.
4. Filter the solution using a filter funnel and filter paper to get rid of any solids left.

Question 22

What reagent is used to test for reducing sugars?

Answer 22

Benedict’s solution.

Question 23

What additional steps should be taken other than adding Benedict’s solution?

Answer 23

Place the mixture of the solution and food sample in a water bath set about 75°c and leave for about 5 minutes.

Question 24

What is a positive result for reducing sugars?

Answer 24

Benedict’s solution turns a brick red colour (could also turn yellow/green if there is less sugar)

Question 25

What reagent is used to test for protein?

Answer 25

Biuret solution

Question 26

What is a positive result for proteins?

Answer 26

Biuret solution turns pink/purple.

Question 27

What reagent is used to test for lipids?

Answer 27

Sudan III

Question 28

What reagent is used to test for starch?

Answer 28

Iodine solution.

Question 29

What is a positive result for starch?

Answer 29

Iodine solution turns a blue/black colour.

Question 30

What enzymes are involved with digestion?

Answer 30

Carbohydrase, lipase and protease.

Question 31

Why are enzymes important in digestion?

Answer 31

They break down large molecules that can’t be absorbed into the blood stream, down into smaller molecules.

Question 32

What is the function of carbohydrase?

Answer 32

To break down carbohydrates to simple sugars.

Question 33

What is amylase?

Answer 33

A carbohydrase that breaks down starch.

Question 34

What is the function of protease?

Answer 34

To break down proteins into amino acids.

Question 35

What is the function of lipase?

Answer 35

To break down lipids into glycerol and fatty acids.

Question 36

Where is amylase produced?

Answer 36

Salivary glands, pancreas, small intestine.

Question 37

Where is protease produced?

Answer 37

Stomach, pancreas, small intestine.

Question 38

Where is lipase produced?

Answer 38

Pancreas, small intestines.

Question 39

What two conditions can affect how enzymes work?

Answer 39

Temperate and PH.

Question 40

What happens as the temperature of an enzyme controlled reaction increases?

Answer 40

The rate of the reaction will also increase, but only until a certain temperature.

Question 41

Why does the enzyme stop working past a certain temperature?

Answer 41

The enzyme has become ‘denatured’.

Question 42

What happens when an enzyme becomes ‘denatured’?

Answer 42

The active changes shape, meaning it will no longer compliment the correct substrate.

Question 43

How does PH affect enzymes?

Answer 43

Enzymes have an optimum PH. Anything above or below this will cause it to become denatured.