Chapter 4 - Cells Exchange Matter Flashcards
What is the concentration gradient?
The difference in concentration of a gas over a distance.
What is the structure of a cell membrane?
- phospholipid bilayer
- hydrophilic heads
- hydrophobic tails
What is diffusion?
The passive process of the movement of molecules across a concentration gradient.
What is osmosis?
The diffusion of water across a membrane.
What is facilitated diffusion?
The movement of a substance from a high concentration to a low concentration through a carrier protein molecule.
What is endocytosis?
The bringing in of a liquid or solid through vesicular transport.
What is exocytosis?
When the contents of a vesicle are passes to the outside of a cell.
What is phagocytosis?
The brining in of solids via endocytosis.
What is pinocytosis?
The bringing in of liquids via endocytosis.
What is active transport?
The movement of substances against the concentration gradient from an area of low concentration to an area of high concentration.
What substances are transported by simple diffusion?
- oxygen
- carbon dioxide
- sodium, calcium and potassium ions
What substances are transported by osmosis?
Water
What substances are transported by facilitated diffusion?
- glucose
- amino acids
What substances are transported by active transport?
- certain ions
- glucose
- amino acids
What substances are transported by endocytosis?
- cholesterol
- iron ions
- micro-organism and cell debris by specialised cells
