SBI3C1 - Unit 1: Cellular Biology
Name : ______________________ Date : ___________________
Lesson 6 – Movement Across the Cell Membrane
Cell Membrane
 Separates the _________from its outside environment
 Certain things need to move ________and other things need to move ______ of the cell
 It controls what gets or out of the cell
 Semi - ________________ : allows only ____________ molecules to move in and out of the cell
Cell Membrane Transport

Passive Transport
1) Simple __________/ Osmosis
2) ________________ Diffusion

Active Transport
1) ________cytosis
2) ________cytosis
Which Molecules Can Pass Through?
By Passive Transport

Small ____________ Molecules : Water, Oxygen, Carbon Dioxide
By Active Transport

Large _____________ Molecules: Glucose, triglycerides, amino acids, ions
1) Simple Diffusion
 Movement of molecules from an area of __________ concentration to ___________ concentration
 No energy (ATP) is needed

Temperature affects the rate of _____________

Higher temperatures _____________ the rate of diffusion.
2) Facilitated Diffusion

Some molecules can’t pass through the membrane

They use ____________ as “______________” to move the molecules across

No energy (ATP) is needed

Osmosis
 A type of _______________
 The movement of _____________ from _________ solute concentration to high ____________ concentration
 Cell survival depends on keeping __________ balanced
Hypotonic Solution
 A solution with ______ solute concentration than ______ the cell

When a cell is in a _______________ solution, water _________ by osmosis and the cell gets ____________ (swell)

Example: Salt water fish in fresh water o Problem: cells swell & burst
Hypertonic Solution

A solution with ____________ solute concentration than inside the cell

When a cell is in a ______________ solution, water ___________ by osmosis and the cell gets
______________ (shrink)

Example: Drinking water from the ocean o Problem: cells shrink and die
Isotonic Solution

No difference in solute concentration between cell
& environment
 Example: _____________ o problem: none
Active Transport
1) Endocytosis
 Cells need to bring in __________ molecules into the cell

Uses energy (___________)

2 types of ______________
a) phagocytosis (cell ____________)
b) pinocytosis (cell ______________)

2) Exocytosis
 Cells need to get rid of ___________ materials
 Small ______________ form and move towards the membrane.
 They _____________ with the cell membrane, releasing the material to the outside.
Homework Questions
1.
Draw a Venn diagram to compare passive and active transport.
2.
List the molecules that are transported across the membrane by passive transport.
3.
List the molecules that are transported across the membrane by active transport.
4.
Research and list two examples of the advantages of osmosis in plants and animals.