B3 Extra

Question 1

What is the hierachy of tissues in the body

Answer 1

Cells–>tissues—>organs—>organ systems—>organisms

Question 2

What happens if PH is too high or too low

Answer 2

If PH is too high or too low it interferes with the bonds holding the enzyme together . This changes the shape of the active site of the enzyme and causes it to become denatured

Question 3

What is usually the best PH for an enzyme to work at

Answer 3

Enzymes usually work best at Ph 7

Question 4

What PH does the pepsin enzyme work best at

Answer 4

Pepsin (which breaks down protiens in the stomach) works best at PH 2 which means its suited to the acidic conditions of the stomach

Question 5

Where is bile produced,stored and released into

Answer 5

Bile is produced by the liver, it is stored in the gall bladder and released into the small intestine

Question 6

What does bile do in the small intestine.

Answer 6

The hydrochloric acid from the stomach makes conditions too acidic for enzymes in the small intestine to work . Bile neutralises the stomach acid in the small intestine and makes the PH perfect for the enzymes to work in

Question 7

What does the salivary gland do

Answer 7

The salivary gland produces the enzyme amylase

Question 8

What is the function of the rectum

Answer 8

The rectum is where the feaces are stored before they leave through the anus

Question 9

What happens in the large intestine

Answer 9

In the large intestine excess water is absorbed from food

Question 10

What is the function of the gall bladder

Answer 10

The gall bladder is where the bile is stored before it is released into the small intestine

Question 11

What is the function of the liver

Answer 11

The liver is where bile is produced . Bile neutralises stomach acids and emulsifies fats

Question 12

What does the pancreas do

Answer 12

The pancreas produces protease,amylase and lipase . It releases these into the small intestine

Question 13

What does the stomach do

Answer 13

• The stomach pummels the food with its muscular walls
• Stomach produces the protease enzyme ,pepsin
• It produces hydrochloric acid : to kill bacteria,to give the right Ph for protease to work (PH 2)

Question 14

What does the small intestine do

Answer 14

The small intestine produces protease,amylase and lipase

-It is where digested food is absorbed out of the digestive system into the blood

Question 15

What is the thorax

Answer 15

The thorax is the top part of the body

Question 16

Whta are the lungs protected by

Answer 16

The lungs are protected by the ribcage

Question 17

What surrounds the lungs

Answer 17

Pleural membranes surround the lungs

Question 18

Where does the air we breathe in go to

Answer 18

The air we breathe in goes to the trachea

Question 19

What does the trachea split into

Answer 19

The trachea splits into two tubes called the bronchi, one goes to each lung

Question 20

What do the bronchi split into

Answer 20

The bronchi split into smaller tubes called bronchioles which eventually end at alveoli

Question 21

What happens in the alveoli

Answer 21

Gas exchange takes place in the alveoli

-Each alveoli is surrounded by a network of blood cappilaries

Question 22

How does gas exchange take place in the alveoli

Answer 22

The blood in the blood capillaries passing next to the alveoli have just returned to the lungs from the rest of the body so contain lots of carbon dioxide and very little oxygen. Oxygen diffuses out from the alveoli ( where there is a high concentration ) to the blood (low conc) and carbon dioxide diffuses out of the blood into the alveoli to be breathed out

Question 23

What happens when the red blood cells carrying oxygen reach the body cells

Answer 23

When red blood cells reach body cells oxygen diffuses from the red blood cells (high conc)into the body cells(low conc) . Carbon dioxide simultaneously diffuses from body cells into red blood cells ready to be carried back to the lungs

Question 24

What do cappilaries do

Answer 24

Cappilaries carry blood very close to every cell in the body so substances can be exchanged

-They supply food and oxygen and take away waste e.g co2 from blood cells

Question 25

What adaptations do cappilaries have to allow efficient substance exchange

Answer 25

• Cappilaries have permeable walls so substances can diffuse in and out
• Cappliaries have walls one cell thick . This increases the rate of diffusion by decreasing the diffusion pathway distance

Question 26

How are exchange surfaces adapted in multi cellular organisms to maximise effectiveness

Answer 26

• Exchange surfaces have a thin membrane so there is only a short distance to diffuse
• Exchange surfaces ahge a large surface area for a higher rate of diffusions
• Exchange surfaces in animals have lots of blood vessels to get stuff in and out of the blood quickly
• Gas exhange surfacss in animals are often ventilated too - air moves in and out

Question 27

How can active transport be used in the gut

Answer 27

Active transport can be used in the gut so that nutrients can be taken from the gut too the blood even if there is a smaller concentration of nutrients in the blood