The Human Digestive System

Question 1

What is a tissue?

Answer 1

A group of cells with similar structure and function working together. e.g muscular tissue and glandular tissue.

Question 2

What are organs?

Answer 2

Organs are collections of tissues. Each organ contain several tissues, all working together to perform a specific task.

Question 3

What tissues do the stomach contain?

Answer 3

1. Muscular tissue: to chum food and the digestive juices of the stomach together.
2. Glandular tissue: to produce the digestive juices that break down food.
3. Epithelial tissue: covers the inside and the outside of the organ.

Question 4

What are the functions of the pancreas?

Answer 4

1. It makes hormones to control blood sugar.
2. Produces some enzymes to digest food.
   Contains two very different type of tissue which produce these different secretions.

Question 5

What are large multicellular organisms made up of?

Answer 5

Made up of a number of organ systems working together.

Question 6

What is an organ system?

Answer 6

Groups of organs which work together to perform specific functions.

Question 7

What are some examples of organ systems in the human body?

Answer 7

1. Digestive system
2. Circulatory system
3. Gas exchange system

Question 8

What are some adaptations in organs to make them effective as exchange surfaces?

Answer 8

1. Features to increase the surface area of part of an organ.
2. A rich blood supply to areas where exchange takes place
3. Mechanisms to increase concentration gradient by ventilating surfaces or moving materials on.

Question 9

What are the stages of an organism forming?

Answer 9

1. Cells
2. Tissues
3. Organs
4. Organ systems
5. Organism.

Question 10

What process is taken by the digestive system?

Answer 10

1. Food taken in is made up of large insoluble molecules
2. Body cannot absorb and use these molecules.
3. They need to be broken down or digested to form smaller soluble molecules which can be used and absorbed by the cells.

Question 11

What do glands such as the pancreas and the salivary glands do?

Answer 11

Make and release digestive juices containing enzymes to break down your food.

Question 12

What do enzymes do?

Answer 12

Break down the large, insoluble food molecules into smaller, soluble ones.

Question 13

What does the small intestine do?

Answer 13

Where the soluble food molecules are absorbed into your blood. Once there they get transported in the bloodstream around your body.

Question 14

Why is the small intestine effective?

Answer 14

1. Has a very large surface area as it is overed in villi.
2. Has a good blood supply and short diffusion distance to the blood vessel so it greatly increases diffusion and active transport from the small intestine to the blood.

Question 15

What does the muscular walls of the small intestine do?

Answer 15

Squeeze undigested food onwards into the large intestine.

Question 16

What happens in the large intestine?

Answer 16

Where water is absorbed from the undigested food into your blood. The material left forms faeces. Faeces are stored then passed out of your body through the rectum and anus.

Question 17

What does the liver do in the digestive system?

Answer 17

Produces bile which help in the digestion of lipids.

Question 18

What are the use of carbohydrates?

Answer 18

Provide us with the fuel that makes all other reactions of life possible. They contain carbon hydrogen and oxygen.

Question 19

What are simple sugars?

Answer 19

Two sugar units joined together.

Question 20

What is single sugars?

Answer 20

only one sugar unit

Question 21

What are example of simple and sing sugars?

Answer 21

1. Sucrose (simple)
2. Glucose (single sugars)

Question 22

What are some examples of sources of carbohydrates?

Answer 22

Bread, potatoes, rice, and pasta.

Question 23

What are lipids?

Answer 23

Fats and oils. The most efficient energy store in your body and important energy source in your diet.

Question 24

What are lipids made up of?

Answer 24

Three fatty acids joined to a molecule of glycerol.

Question 25

What are some examples of lipid rich foods?

Answer 25

1. Olive oil 2. Corn oil 3. Cheese 4. Cream

Question 26

What are proteins used for?

Answer 26

Used for the building the cells and tissues of your body and are the basis for all enzymes.

Question 27

What is protein made up of?

Answer 27

Carbon, hydrogen, oxygen

Question 28

What are some examples of protein rich foods?

Answer 28

meat, fish, pulses and cheese

Question 29

What are protein molecules made up of?

Answer 29

Made up of long chains of small units called ammino acids.

Question 30

What does it mean when protein is denatured?

Answer 30

The bonds holding the proteins are very sensitive to temperature and pH, and are easily broken. If this happens, the shape of the protein is lost and may not function anymore.

Question 31

What can our body make using proteins.

Answer 31

1. Structural components of tissues such as muscles and tendons. 2. Hormones such as insulin 3. Antibodies which destroy pathogens and are part of the immune systems. 4. Enzymes, which act as catalysts

Question 32

What are catalysts used for?

Answer 32

To speed up reactions. A catalyst speeds up the rate of reaction but it is not used up in the reaction.

Question 33

What controls the rate of reaction in our bodies?

Answer 33

Enzymes

Question 34

What are enzymes?

Answer 34

Are large protein molecules.

Question 35

Why is the shape of an enzyme vital for the enzyme to function?

Answer 35

The long chains of ammino acids are folded to produce a molecule with an active site. The active site has a unique shape so it can bind to a specific substrate molecule.

Question 36

How do enzymes work?

Answer 36

The substrate fits into the active site of the enzyme. They bind together and the reaction takes place rapidly and the products are released from the enzyme. Enzymes can join smaller molecules together as well as break up larger ones.

Question 37

What examples of metabolic reactions do enzymes control?

Answer 37

1. Building larger molecules from lots of small ones for example starch to glycogen or proteins to ammino acids. 2. Changing one molecule to another such as glucose to frutcose.

Question 38

What happens when enzyme is affected by temperature?

Answer 38

High temperature denature the enzyme changing the shape of the activity site

Question 39

What happens when enzyme is affected by pH?

Answer 39

Affects the active site of the enzyme to make it work efficiently or stop working

Question 40

What are some important features of the digestive system?

Answer 40

1. It is a hollow muscular tube that squeezes food, helping break it up into small pieces with a large surface area for enzymes to work on. 2. It mixes food with the digestive juices so that the enzymes come into contact with as much as the food as possible. 3. The muscles of the digestive system move the food along from one area to the next.

Question 41

What are carbohydrases?

Answer 41

Enzymes that break down carbohydrates. it is catalysed by the enzyme amylase. Produced in the salivary glands also made in the pancreas.

Question 42

What is proteases?

Answer 42

The enzyme that catalyse the protein rich foods. Produced in the stomach, pancreas and small intestine. Broken down into sugars.

Question 43

What is lipase

Answer 43

Enzyme that catalyse lipids into fatty acids and glycerol.

Question 44

Why do lipids not mix well with the watery liquids in the digestive system?

Answer 44

1. They stay as large globules which make it difficult for the lipase enzymes to react.

Question 45

How does bile break down lipids?

Answer 45

The bile emulsifies the lipids in your food. This means the bile breaks up large lipid drops into smaller droplets providing a bigger surface area. This helps the lipase chemically break down the lipids more quickly into fatty acids and glycerol.