Topic 1 - Biological molecules

Question 1

What is mass transport

Answer 1

mass transport is the bulk movement of gases or liquids in one direction, usually via a system of vessels and tubes

Question 2

What are features of a mass transport system

Answer 2

• vessels
• transport medium
• maintains speed

Question 3

Why do some organisms require a mass transport system

Answer 3

Larger animals have a smaller SA to Vol ratio and a higher metabolic rate; diffusion alone is insuffucuent to supply alll cells with the substances they need

Question 4

What makes water a dipolar molecule

Answer 4

Oxygen is more electronegative than hydrogen and thus pulls the shared electrons in the covalent bond closer toward its nucleus. This gives oxygen a partial negative charge and hydrogen a partial positive charge. causing there to be an uneven distribution of electrons

Question 5

Define Adhesion

Answer 5

Attraction of two different molecules

Question 6

Define cohesion

Answer 6

Attraction between 2 of the same molecules

Question 7

What is specific heat capacity

Answer 7

amount of energy required to raise 1kg by 1*c

Question 8

What is hydrolysis

Answer 8

Water molecules breaks one or more chemical bonds

Question 9

Explain why ions dissolve in blood

Answer 9

• water is a component of blood
• dipolar nature of water allows it to surround the ion

Question 10

A student stated that loss of heat when sweating is related to the dipole nature of water
molecules.
Justify this statement. (3)

Answer 10

• Water has an uneven distribution of charge
• so it forms H+ bonds with other water molecules
• so it takes alot of energy to break those bonds