Gas Exchange Topic 3

Question 1

What is the relationship between the size of an organism and the surface area : volume

Answer 1

Larger organisms have a smaller surface area : volume
Faster diffusion

Question 2

What is involved in inspiration

Answer 2

Diaphragm contracts and external intercostal muscles contract
Pressure decrease and volume increase
Air moves down a pressure gradient / air enters from higher atmospheric pressure

Question 3

Describe the counter current principle for fish

Answer 3

Water and blood flow in opposite directions
Maintains diffusion gradient of oxygen
Along length of lamellae

Question 4

What is involved in expiration

Answer 4

Diaphragm relaxes and domes
Internal intercostal muscles contract
Volume decrease and pressure decrease
Air moves to an area of lower pressure (outside of the body)

Question 5

Ways a fish is adapted for efficient gas exchange

Answer 5

Thin so short diffusion pathway
Many lamellae so large surface area

Question 7

Describe the role of the enzymes in the digestive system in the complete breakdown of starch

Answer 7

Amylase
Into maltose
Maltase
Maltose to glucose
Hydrolysis
Of glycosidic bonds

Question 8

Describe the processes involved in the absorption of the products of starch digestion

Answer 8

Glucose moves in with sodium
Via protein
Sodium removed by active transport
Into blood
Glucose moves into blood
By diffusion

Question 9

Describe the processes involved in the absorption and transport of digested lipid molecules from the ileum into lymph vessels

Answer 9

Micelles contain bile salts and fatty acids
Make fatty acids soluble
Fatty acids absorbed by diffusion
Triglycerides reform
Vesicles move to cell membrane