Cells - Cellular Transport Flashcards
What is diffusion?
The movement of atoms or small molecules from an area of high concentration to an area of low concentration, such that an equal and uniform concentration is achieved
What is osmosis?
The diffusion of water
When does osmosis occur?
When there is a semi-permeable membrane - water can pass through but the solute cannot
What occurs during simple diffusion?
Molecules can pass freely through the cell membrane from an area of high concentration to an area of low concentration
Which molecules can travel via simple diffusion?
- oxygen
- carbon dioxide
- water
- lipid molecules
What travels by endocytosis/exocytosis?
- mucus
- digestive enzymes
- hormones
- proteins
What occurs during facilitated diffusion?
Channel proteins open and allow large molecules to pass through via diffusion
What is transported via facilitated diffusion?
- glucose
- carbohydrates
- amino acids
What are the similarities between simple and facilitated diffusion?
Both processes are passive, driven by a concentration gradient
What does the term lyse mean?
Bursts
What does crenate mean?
Shrinks
What hypertonic?
Low water level
What is hypotonic?
High water levels
What happens during active transport?
- doesn’t require a concentration gradient - a way for the cell to control its contents
- transport against a concentration gradient
- carrier mediated
- requires energy from ATP
Sodium potassium pump
- ATP used to change the shape of the protein and force Na+ out of the cell
- K+ imported in passively
