Movement of cells and SA Flashcards
What does cell membrane do?
Create barrier between cell & external enviro
What does a cell membrane consist of?
Mainly lipids & proteins. Proteins are placed complexly between phospholipids & control transport of substances in & out of cell.
What is the phospholipid bi layer?
What makes up membrane, that contains embedded proteins & carbohydrates
Phospholipid bilayer
What does cell membrane do?
Allows substances to travel in & out of cells (eg, Oxygen, glucose, CO2, excess water) and makes a barrier.
What do transport proteins do?
Some substances (eg protein) to large for cell membrane & must be moved through transport layer.
Where can smaller molecules pass through cell membrane?
Phospholipid bilayer.
What is diffusion?
Movement of molevules from area of high to low concentration.
What type of transport does diffusion use?
passive
Why does diffusion occur and where does it occur more quickly?
Because particles move. Occurrs faster in gases than liquids.(Not in solids)
In cells, what can diffusion move?
Oxygen, CO2, chloride ions
What affects rate of diffusion?
- Heat
- State of matter
- Concentration
Define osmosis
Diffusion of substance (usually H2 O) across selectively permeable membrane.
Or
Movement of H2 O from a solution of low solute conc. to high solute conc.
Active transport
movement of substnaces against concentration gradient (from H to L)
Does active transport use passive transport?
NO, needs cellular energy and uses transport proteins.
If cell has low SA/V ratio, is it efficient?
No,
What is an efficient cell?
It has a high SA/V ratio. (Long and thin)
The greater the SA/V ratio, the more efficient the cell
What is relationship between structures?
Cell-Tissues-Organs-OrganSystem
Cell
Smallest structural unit of organism
What are a group of similar cells?
Tissues
What are organs
Group of tissues adapted for specific function
What are a group of organisms that work together for 1 or more functions?
A organ system
What does a nerve cell consist of?
Glial cells, dentrites, axons, cell body.
How does structure of nerve relate to its function?
Long projections (axons and dentrites) allow for efficient transmission of messages.
