Chapter 3

Question 1

What is tissue?

Answer 1

A group of cells with a similar structure and function working together.

Question 2

What is an organ?

Answer 2

Organs are collections of tissues working together for a specific function.

Question 3

What is an Organ system?

Answer 3

Organ systems are groups of organs working together to perform a specific function. Examples are the digestive system, the circulatory system and the gas exchange system.

Question 4

All systems have adaptions to make them more effective as exchange surfaces what are they?

Answer 4

• a rich blood supply
• areas with short diffusion distances
• mechanisms to increase the concentration gradient

Question 5

What tissues does the stomach contain?

Answer 5

Epithelial tissue - which covers the inside and outside of the organ.

glandular tissue- to produce the digestive juices that break down food.

Muscular tissue - to churn the food and digestive juices together.

Question 6

What does the liver do?

Answer 6

Produces bile

Question 7

What does the stomach do?

Answer 7

Breaking down large insoluble molecules into smaller I soluble molecules.

Question 8

What does the small intestine do?

Answer 8

Breaks down large insoluble molecules into smaller I soluble molecules and absorption.

Question 9

What does the large intestine do?

Answer 9

Absorbs water from undigested food.

Question 10

What are carbohydrates?

Answer 10

• They are made of sugar units.
  Complex carbohydrates contain long chains of simple sugar units bonded.
• Fuel for reactions
• Broken down into glucose to provide energy for metabolic reactions in your cells.

Question 11

What are lipids?

Answer 11

Lipids are fatty acids and oils.
Most efficient energy store in your body.
Combine with other molecules, to become important in cell membranes as hormones in your nerve system.

Question 12

What are proteins?

Answer 12

Proteins are used for building cells and tissues and the bases of enzymes.
Protein is made up of long chains of amino acids
Structural components of of tissues
Antibodies and enzymes

Question 13

What are enzymes?

Answer 13

Enzymes are special biological catalysts which speed up reactions. Each enzyme interacts with a specific substrate.
The shape is crucial to the amino acids are folded so they are in specific shape for a unique substrate.

Question 14

What do enzymes control?

Answer 14

Metabolism - the sum of all reactions

Different enzymes speed up specific types of metabolic reactions.

Question 15

List 3 metabolic reactions.

Answer 15

Building large molecules from lots of smaller ones. Such as building starch, glycogen or cellulose from glucose.
Changing one molecule into another. This includes simple sugar to another, converting amino acids to another.
Breaking down large molecules into smaller ones. This includes breaking down carbohydrates lipids and proteins

Question 16

What temperatures do most enzymes react best at?

Answer 16

The rate of an enzyme-controlled reaction increases as the temperature rises - but only until the protein structure of enzyme breaks down.
They tend to begin to break down at 40C
Human enzymes work best at 37C

Question 17

What organs in the digestive system are slightly acidic to allow enzymes to work?

Answer 17

The stomach has a low ph acidity

Question 18

What organs in the digestive system are slightly alkaline?

Answer 18

Mouth and small intestine

Question 19

What is the enzyme that catalysts carbohydrates?

Answer 19

Amylase, this works at an optimum condition of Ph 8

Question 20

What enzymes is protein catalysed by?

Answer 20

Protein is catalysed by protease

Question 21

What happens when lipids are broken down?

Answer 21

They are broken down into fatty acids and glycerol this reaction is catalysed by lipase.

Question 22

What lines your stomach to protect it from Hydrochloric acids?

Answer 22

A thick layer of mucus.

Question 23

Where are some of the enzymes that catalyse digestion made?

Answer 23

They are made in your Pancreas.

Question 24

Why are fats surface area altered by bile?

Answer 24

They are altered as they don’t mix with all the watery liquids.