Chapter 3 Flashcards
What are the Major components of a cells membrane?
1) phospholipids
2) cholesterol gives it strength
3) carbohydrates on the outside
What are the 3 parts of a cell?
1) plasma membrane- outer boundary of a cell
2) cytoplasm- intercellular fluid
3) nucleus- house genetic info(DNA) of a cell
Describe phospholipids:
- Hydrophilic head attached to water
- Hydrophobic tails made up of 2 fatty acid chains.
How do substances move across the cell membrane?
They move across actively and passively
What is passive transport?
No energy is used from the cell. There are 2 passive processes:
1) diffusion
2) filtration
What is active transport?
The cell uses ATP to allow substances to cross the membrane.
What is diffusion?
It’s an passive transport. It’s a tendency of molecules or ions to move from an area of high concentration to low concentration. The driving force is kinetic energy.
How is the speed of diffusion effected?
It’s effected by the size of molecules and the temperature.
Smaller=faster
Warmer=faster
How can ions and molecules cross the cell membrane?
It can cross if it’s:
1) lipid solvable
2) non polar
3) assisted by carrier molecules
What is simple diffusion?
Movement of particles from a high concentration to low concentration without an input of energy.
What is facilitated diffusion?
Substances move from a high concentration to low concentration without energy input.It’s a type of passive transport process. The transported substance binds to a protein carrier in the membrane and is ferried across. Or it can move through a water filled protein channel.
What are the 2 types of channels?
1) leakage channel- it’s always open
2) gated channel- has gates that open and close by chemical or electrical signals
What is osmosis?
Diffusion of water through a selectively permeable membrane.
What is osmolarity?
Total concentration of all solute particles in a solution.
What is tonicity?
Ability oF a solution to change the shape or tone of cells by altering the cells internal water volume.
What are the 3 forms of tonicity?
1) isotonic solution
2) hypotonic solution
3) hypertonic solution
How does an isotonic solution effect the cell?
It doesn’t because the osmolarity of the solution is equal to the osmolarity of the cell.
How does a hypotonic solution effect the cell?
There is a lower concentration of non penetrating solute compared to the cell. Water will move into the cell causing it to swell.
How does a hypertonic solution effect the cell?
There is a higher concentration of non penetrating solute than inside the cell. The cell will lose water causing it to shrink.
What is active transport?
When the cell uses energy to move solutes across the membrane.solutes are moved from a high concentration to a low concentration.
What are the 2 types of active transport?
1) primary active transport- breaks down ATP and turns it into adp
2) secondary active transport- is driven by energy that is stored in ionic gradients created by primary active transport pumps.
What is symport system?
It transport 2 substances in the same direction. Either into or out of a cell.
What is the antiport system?
The antiport system moves substances in opposite directions.
What are the functions of carbohydrates?
The major function is to provide a ready, easily used source of cellular fuel (energy). Most cells can use only a few simple sugars, Glucose is at the top of the “cellular menu”. Glucose is used during oxidation reduction rxns to be broken down and oxidized within cells.
