B3: Organisation And The Digestive System🍔

Question 1

What is a tissue?

Answer 1

A group of cells with similar structure and function that work together.

Question 2

What is an organ?

Answer 2

Collections of tissues.

Question 3

What is an organ system?

Answer 3

Groups of organs that work together to perform specific functions.

Question 4

Name the parts of the digestive system. (IN ORDER)

Answer 4

Mouth, gullet, stomach, liver, bile duct, small intestine, large intestine, rectum, anus.

Question 5

What do carbohydrates provide?

Answer 5

The fuel that makes all other reactions of life possible. (Hydrogen, carbon, oxygen)

Question 6

What are lipids for?

Answer 6

They are the most efficient energy source in our diet.

Question 7

What are proteins for?

Answer 7

They are for building up cells and tissues of your body.

Question 8

What are lipids made up of?

Answer 8

Fatty acids joined to a molecule of glycerol.

Question 9

What are proteins made of?

Answer 9

Amino acids.

Question 10

How do you test for starch?

Answer 10

Iodine turns from yellow to blue-black if starch is present.

Question 11

How do you test for sugars?

Answer 11

Benedict’s solution goes from blue to brick red on heating if sugar is present.

Question 12

How do you test for protein?

Answer 12

Biuret goes from blue to purple if protein is present.

Question 13

How do you test for lipids?

Answer 13

Ethanol has a cloudy white layer is lipids are present.

Question 14

What is a catalyst?

Answer 14

They speed up chemical reactions without being used up themselves.

Question 15

What are enzymes?

Answer 15

Biological catalysts.

Question 16

How do enzymes work?

Answer 16

The substrate fits perfectly into the enzyme active site. The substrate splits into products which leave the active site.

Question 17

What happens to enzymes if temperature is increased?

Answer 17

The reaction speeds up until a certain point. After that the amino acid chains making up the active site, begin to unravel. This is called DENATURING.

Question 18

What happens to enzymes if the pH is changed?

Answer 18

Different enzymes work best at different pH levels. A change in pH can stop them working completely because it affects the forces holding together the different parts of protein molecules.

Question 19

What does digestion involve?

Answer 19

The breaking down of large molecules into smaller ones.

Question 20

Carbohydrases break down?

Answer 20

Carbohydrates to simple sugars.

Question 21

Proteases break down?

Answer 21

Proteins to amino acids.

Question 22

Lipases break down?

Answer 22

Lipids to fatty acids and glycerol.

Question 23

What is the enzyme that is secreted from the stomach?

Answer 23

Pepsin.

Question 24

In what pH does pepsin work best in?

Answer 24

An acidic pH.

Question 25

In which pH do the enzymes that come from your pancreas work best in?

Answer 25

Alkaline pH

Question 26

What does bile do? (pH levels)

Answer 26

Bile neutralises the acid that was added to the food in the stomach. It provides alkaline conditions for the enzymes in the small intestine so that the work best.

Question 27

What does bile do?(emulsification)

Answer 27

It emulsifies the fats in your food. It breaks up large droplets of fat into smaller ones. It provides a bigger surface area for lipase to act upon.