Chapter 7 - The Passage of Substances Accross the Cell Surface Membrane Flashcards
State four reasons why substances need to enter and exit cells
- Cells need building materials and energy to carry out the process of life
- Cells need to get rid of metabolic waste
- Substances need to be in appropriate quantities
- The entry and exit of substances is continuous and very heavy
Define diffusion
The movement of atoms, molecules and ions from an area of high concentration to an area of low concentration
Describe a passive process
No energy is required for the process to take place
Name three passive processes
- Diffusion
- Osmosis
- Facilitated diffusion
Through which part of the cell surface membrane does diffusion take place?
Phospholipid bilayer
Through which part of the cell surface membrane does facilitated diffusion take place?
Channel proteins
Through which part of the cell surface membrane does active transport take place?
Carrier proteins
Through which part of the cell surface membrane does osmosis take place?
Phospholipid bilayer
State four substances which move by diffusion
- Fatty acids
- Potassium ions
- Sodium ions
- Gases
Describe gaseous deffusion
The diffusion of oxygen and carbon dioxide accross the mammalian respiratory system and the stomata of plants
Describe solute diffusion
The diffusion of molecules like glucose over the human digestive system
Name the molecules which move by facilitated diffusion
- ATP
- Glucose
- ADP
- Ions
Give one example of a hypotonic solution and one example of a hypertonic solution
Hypertonic: Salt water
Hypotonic: Distilled water
Give one example of where active transport takes place
The movement of vitamins and minerals into the root hair cells of plants
Name the molecules which move by active transport
- Glucose
- Vitamins
- Minerals
