Unit 1 - AOS1 - Diffusion and Cell Size Flashcards
Diffusion
Movement of substances from an area of high concentration to low concentration
When a cell is small… (sa:v)
It has a large surface are in comparison to its volume.
- larger surface area to volume ratio
When a cell is larger… ( sa:v)
It’s surface area compared to its volume is small
- small surface area to volume ratio
What does a large surface area to volume ratio cause to the cell?
It places a limit o the size a cell can grow
- Thai is with the effectiveness of diffusion being the controlling factor
- larger organisms overcome this constraint by becoming multicellular
Surface area- unit of measurement, and formula
- cm^2
- side length x side length x 6 (cube)
Volume- unit of measurement, and formula
- cm^3
-height x width x depth (cube)
Do cells use energy to move molecules?
no
Diffusion
Molecules move from an area of high concentration to low concentration.
-How molecules move into and out of cell
Types of Passive Transport
- Diffusion
- Osmosis
- Facilitated diffusion
What do the molecules want to reach through the process of passive transport?
Equalibrium
Osmosis
- Diffusion of water from an area of high to low concentration.
- Only water moves to create an equilibrium between 2 solutions.
Hypotonic
- Lower concentration of solutes
- Higher concentration of water
Hypertonic
- higher concentration of solutes
- Lower concentration of water
What will happen to a cell when placed in a hypotonic environment?
Swell
What will happen to a cell when placed in a hypertonic environment?
Shrivel
