1.1 Transport Around The Body

Question 0

Define diffusion

Answer 0

The free movement of particles down a concentration gradient, form a hypotonic solution to a low water potential, hypertonic solution.

Question 1

Name the four types of movement of substances when moving in and out of cells.

Answer 1

Diffusion

Osmosis

Facilitated diffusion

Active transport

Question 2

Why can substances diffuse directly from inside a cell to its external environment in organisms such as amoeba?

Answer 2

Because it is a unicellular organism

Large surface area : volume ratio

Question 3

How do large organisms differ from unicellular?

Answer 3

Made up of billions of cells

Often contain specialized tissues and organs

SUBSTANCES NEED TO TRAVEL LONG DISTANCES TO REACH CYTOPLASM OF CELLS

Question 4

Why do large organisms need mass transport systems?

Answer 4

So cells are provided with nutrients fast enough, as diffusion pathways from internal cells to external environment is too long for diffusion to happen quick enough.

So cell reactions can occur quick enough

Question 5

Give an example of a mass transport system

Answer 5

Cardio vascular system (heart and circulatory system)

Question 6

What is active transport?

4 points

Answer 6

When ATP is broken down by ATPase, breaking a bond to produce ADP

The energy released is used to to change the shape of a carrier system which will actively transport a substance across a membrane, AGAINST a concentration gradient

One way system/transport occurs in 1 direction

FASTER than diffusion

Question 7

What are 3 features of a mass transport system?

Answer 7

It must have a SUITABLE TRANSPORT MEDIUM (e.g Blood)

A means of MOVING MATERIALS FAST ENOUGH (CONCENTRATION GRADIENT/ PRESSURE FROM MECHANICAL HEART)

A system of vessels that provide WIDE SPREAD BRANCHING/ large surface area