science hw cards

Question 1

Name and describe 3 ways the human body defends against the entry of pathogens.

Answer 1

Skin – barrier, nose - nasal hairs , mucus and cilia, trachea & bronchi – mucus to catch, cilia to remove from lungs, stomach - HCl acid kills.

Question 2

What is an antigen

Answer 2

A protein on the surface of a pathogen.

Question 3

Why are dead or inactive pathogens used in a vaccine

Answer 3

To stimulate white blood cells to make antibodies without causing the disease.

Question 4

why will the antibody produced for measles not be effective in other diseases

Answer 4

Antibody has a specific shape which fits with a specific antigen.

Question 5

What is an antibiotic and what is it used for

Answer 5

kills bacteria inside the body without harming the cell

Question 6

define Organism

Answer 6

A group of organ systems working together.

Question 7

define Organ system

Answer 7

A group of organs working together to perform a specific function.

Question 8

define Organ

Answer 8

A group of tissues working together to perform a specific function.

Question 9

define Tissue

Answer 9

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

Question 10

define Cell

Answer 10

The smallest structural and functional unit of an organism.

Question 11

What is digestion?

Answer 11

Large insoluble molecules are broken down into smaller soluble ones.

Question 12

What is an enzyme?

Answer 12

A biological catalyst – they speed up the rate of reaction without being used up.

Question 13

What biological molecule are enzymes made of?

Answer 13

Proteins.

Question 14

What is the active site of an enzyme?

Answer 14

It is where the substrate binds

Question 15

What is a substrate?

Answer 15

Substance (chemical) that the enzyme acts on.

Question 16

What are the products of digestion used for in the body?

Answer 16

They are used to build new carbohydrates, lipids and proteins in the body. Glucose is used in respiration.

Question 17

What does denatured mean?

Answer 17

That the active site of the enzyme has changed shape so the substrate cannot fit.

Question 18

How does increasing the temperature affect enzyme activity?

Answer 18

Initially it increases the rate of reaction due to increased collisions between the enzyme and substrates, if the temperature is too high the enzyme will denature.

Question 19

How does pH affect enzyme activity?

Answer 19

Enzymes have optimum pH conditions, if these are too alkaline or acidic the enzyme denatures

Question 20

What is the role of bile in digestion?

Answer 20

It neutralises stomach. (hydrochloric) acid and emulsifies fats.

Question 21

Where in the body is bile made?

Answer 21

Bile is made in the liver and stored in the gall bladder.

Question 22

What is a double circulatory system?

Answer 22

Where blood from the heart is pumped to the lungs and the body at the same time.

Question 23

What is a pacemaker?

Answer 23

A group of cells in the right atrium that controls the heart rate.

Question 24

What is the role of the coronary arteries?

Answer 24

To supply oxygenated blood to the heart muscle.

Question 25

Where does the left atrium pump blood to?

Answer 25

To the left ventricle.