4 Gas Exchange And Transport

Question 1

Why organisms need a mass change system specialised gas exchange surfaces as the increase in size

Answer 1

Heart is needed to pump blood around the body
In a mass flow system
Due to a small SA:Vol
And overcome the limitations of diffusion (e.g. large diffusion distance)
And transport waste products and other molecules like oxygen
Due to high metabolic activity

Question 2

Role of mass transport system

Answer 2

Mass transport system helps maintain a steep concentration gradient and ensures efficient cell activity

Question 3

Diffusion

Answer 3

Passive net movement of molecules from a high concentration to a lower concentration down a diffusion gradient

Question 4

Facilitated diffusion

Answer 4

The movement of molecules or ions from an area of lower concentration to a higher concentration with the assist of carrier proteins in the membrane, utilising cell energy

Question 5

Osmosis

Answer 5

The movement of water molecules from a solution with a high concentration of water molecules to a solution with a low concentration of water molecules through a cells partially permeable membrane

Question 6

Understand how the properties of molecules affects how they are transported

Answer 6

Solubility: soluble molecules can diffuse through
Size: large molecules or less permeable
Charge: charged molecules rely on facilitated diffusion use the polar head of the phospholipid causing repulsion

Question 7

Water potential equation

Answer 7

Water potential= turgor pressure + osmotic potential

Question 8

Adaptation of insect trachea for gas exchange

Answer 8

Supported by rings of chitin to prevent collapse
Divided into smaller tubes called tracheoles
Tracheoles extends through the whole body and can extend between cells
0.1 mm diameter and a gas exchange happens across the fluid-filled tips forming a diffusion gradient

Question 9

Adaptation of insect spiracle for gas exchange

Answer 9

Opens and closes by muscle valves
To decrease water loss

Question 10

How insect adaptations increase gas exchange efficiency

Answer 10

large SA:Vol due to tracheoles and increased fluid is withdrawn from tips
Steep conc grad maintained between tracheoles and body cells due to respiration and pumping movement of abdomen
Shirt diffusion distance between tracheoles walls and tissues
Constant flow of air through the tracheole system to maintain ventilation of tissues

Question 11

Movement of gases in insect tracheole system

Answer 11

Along diffusion gradient due to respiration
Mass transported by movement of muscles which squeeze trachea enabling air to move in and out
Removal of water through tracheole tips

Question 12

Operculum fish