2.2 - Movement Across Membranes Flashcards
The concentration of chemicals is different between what environments?
Intracellular environment (inside of the cell) and extracellular environment (outside of the cell).
What does the cell need to do in order for enzymes to function properly?
Maintain precise chemical concentrations.
Why does the cell need to maintain precise chemical concentrations?
To ensure that the enzymes function properly.
What materials must also be regulated in the cell?
The amount of water and waste.
How can molecules pass through the cell membrane?
With passive transport (no energy input) or active transport (with energy input).
What factors influence how molecules move through the cell membrane?
Size
Shape
Charge
Concentration
What does the cell membrane help with?
Maintain internal composition
Internal composition is maintained through what two key processes?
- Passive Transport
2. Active Transport
How do cells vary in efficiency in maintaining the intracellular environment?
Size of the cells
The most efficient cells are SMALL, meaning they have a HIGH Surface Area : Volume Ratio.
What are the two types of PASSIVE transport?
- Diffusion
2. Osmosis
What is diffusion?
The movement of a substance from an area of HIGH CONCENTRATION to an area of LOW CONCENTRATION
What is another type of diffusion?
Facilitated Diffusion
What is facilitated diffusion?
A type of diffusion where molecules move across a membrane with the help of a specific internal protein.
What is osmosis?
The movement of WATER through a SEMI-PERMEABLE MEMBRANE from an area of LOW CONCENTRATION to an area of HIGH CONCENTRATION of the DISSOLVED SUBSTANCE.
What is ACTIVE transport?
Form of movement across cell membranes where ENERGY IS REQUIRED to move a substance AGAINST A CONCENTRATION GRADIENT.
