Chapter 2 - The importance of water

Question 1

Properties of water

Answer 1

1. High specific heat capacity
2. Transparent
3. High heat latent evaporation
4. High cohesion between molecules
5. Universal solvent
6. Low density when solid
7. Adhesive properties
8. Molecular motility

Question 2

What is the biological importance of water having a high specific heat capacity?

Answer 2

• hydrogen bonds between H2O molecules absorb high amounts of energy
• important for keeping aquatic habitats thermally stable
• important for stabilizing internal body temperature as environment changes

Question 3

Biological importance of water being transparent?

Answer 3

• Allows light to pass through it

- important for light dependent stage of PHS

Question 4

Biological importance of water having a high heat of latent evaporation

Answer 4

• important in thermoregulation of mammals

- evaporation of water removes heat from surface of skin and tongue

Question 5

Biological importance of water having high cohesion between molecules

Answer 5

• important in transpiration stream
• provides supportive role:hydrostatic skeleton
• enables motility of aquatic organisms

Question 6

Biological importance of water being the universal solvent

Answer 6

• important for transporting ions, proteins etc.
• important for removing waste
• important in allowing chemical reactions to take place inside cells
• metabolic functions

Question 7

Biological importance of water having a low density when solid

Answer 7

• important for insulating water beneath ice
• forms a surface for habitats
• produces circulation currents in large bodies of water

Question 8

Biological importance of water having adhesive properties

Answer 8

• acts as a lubricant:

Pleural fluid, mucus, synovial fluid

Question 9

Biological importance of water having molecular motility

Answer 9

• allows osmosis to occur

Question 10

Method for testing for reducing sugars

Answer 10

1. Add an equal amount of Benedict’s reagent to the solution to be tested.
2. Place in water bath at 90 degrees for 5-10 mins
3. Observe the color of the precipitate

Question 11

What is a biosensor?

Answer 11

• an analytical device that uses a biological molecule to detect the presence of a specific chemical molecule

Question 12

What are the main components of a biosensor?

Answer 12

1. Molecular recognition (bio receptor)
2. Transduction
3. Amplifier
4. Display (processor)