Exchange of Nutrients & Wastes (PPT 5-6) [U1/ T2]

Question 1

Explain why chemical digestion is required in the digestive process?

Answer 1

To break apart complex molecules into simple molecules. This action is carried out by digestive enzymes, they make macromolecules into macromolecules to enable them to diffuse across membranes.

Question 2

Describe the role of the digestive enzymes amylase, protease & lipase in chemical digestion.
Include the following
- What the chemical digestion is of?
- The location in the digestive system

Answer 2

Amylase:

• Digestion of carbs
• Starts at mouth, ends in small intestine.

Protease:

• Digestion of proteins
• Starts at stomach, ends in small intestine.

Lipase:

• Digestion of lipids
• Occurs in the small intestine.

Question 3

What three things make an effective absorptive surface?

Answer 3

• Adequate SA/V ratio for max absorption
• Close proximity to the transport fluid & system
• Mantained favourable concentration gradient

Question 4

Name 2 examples of metabolic waste

Answer 4

• Carbon dixode
• Urea
• Excess water
• Salts

Question 5

What are the 3 types of nitrogenous wastes used by animals?

Answer 5

• Ammonia
• Urea
• Uric acid

Question 6

Fill in the following information regarding ammonia.

Size of molecule:
Toxicity:
Solubility:
Used as an excretory product:

Answer 6

Size of molecule:
Toxicity: Highly toxic
Solubility: Very soluble
Used as an excretory product: Aquatic organisms

Question 7

Fill in the following information regarding urea.

Size of molecule:
Toxicity:
Solubility:
Used as an excretory product:

Answer 7

Size of molecule:
Toxicity: Less toxic than ammonia
Solubility: Moderatly soluble
Used as an excretory product: Mammals

Question 8

Fill in the following information regarding uric acid.

Size of molecule:
Toxicity:
Solubility:
Used as an excretory product:

Answer 8

Size of molecule:
Toxicity: Relatively non-toxic
Solubility: Highly insoluble
Used as an excretory product: Birds & reptiles

Question 9

What are the 3 basic functions of the kidney?

Answer 9

• Remove metabolic waste from bood
• Help maintain electrolyte, pH & fluid balances
• Release key hormones

Question 10

What is the nephron composed of?

Answer 10

• Bowmans capsule
• Glomerulus
• Tubule region, inclduing Loop of Henle, proximal & distal tubes.

Question 11

What are the 3 basic steps the nephron uses to filter the blood?

Answer 11

1) Filtration
2) Reabsorption
3) Secreation