GCSE Biology – Unit 1 – Cell Biology
Transport in Cells #2: Osmosis & Active Transport
Learning Objectives:
• To define Osmosis and use
the terms dilute solution and
concentrated solution
• Understand the effects of
osmosis on animal and plant
cells
• Learn how sports drinks
relate to osmosis
• Understand active transport
and recall examples in nature
• Compare diffusion, osmosis
and active transport
, Cell Membranes
• The membrane of a cell allow substances to move in and out of the cell
• Organisms need to exchange substances across their cell membranes in order to
function correctly
• Cells need to take up food (e.g. glucose) and get rid of waste products (e.g. urea)
• There are 3 methods of transport across a cell membrane:
• Diffusion Cell Membrane
Glucose
• Osmosis
Oxygen CO2
• Active Transport
Amino Urea
acids
Minerals
, Osmosis
• The movement of water into and out of a cells happen by osmosis
• Osmosis can be defined as:
‘The diffusion of water from a dilute solution to a concentrated solution through a
partially permeable membrane’
• A partially permeable membrane is one that lets some substances through (e.g.
water, oxygen, carbon dioxide etc.) but not others (e.g. glucose, sucrose)
• Water always moves from a dilute solution to a concentrated solution.
Transport in Cells #2: Osmosis & Active Transport
Learning Objectives:
• To define Osmosis and use
the terms dilute solution and
concentrated solution
• Understand the effects of
osmosis on animal and plant
cells
• Learn how sports drinks
relate to osmosis
• Understand active transport
and recall examples in nature
• Compare diffusion, osmosis
and active transport
, Cell Membranes
• The membrane of a cell allow substances to move in and out of the cell
• Organisms need to exchange substances across their cell membranes in order to
function correctly
• Cells need to take up food (e.g. glucose) and get rid of waste products (e.g. urea)
• There are 3 methods of transport across a cell membrane:
• Diffusion Cell Membrane
Glucose
• Osmosis
Oxygen CO2
• Active Transport
Amino Urea
acids
Minerals
, Osmosis
• The movement of water into and out of a cells happen by osmosis
• Osmosis can be defined as:
‘The diffusion of water from a dilute solution to a concentrated solution through a
partially permeable membrane’
• A partially permeable membrane is one that lets some substances through (e.g.
water, oxygen, carbon dioxide etc.) but not others (e.g. glucose, sucrose)
• Water always moves from a dilute solution to a concentrated solution.
