Unit 3 - Cell Transport (etc) Flashcards
What are the lipids responsible for in the plasma membrane? How about the proteins?
Lipids= isolating function Proteins= transport + communication
What are the 3 categories of membrane proteins?
- Transport Proteins
- Receptor Proteins
- Recognition Proteins
What do transport proteins do?
Regulate the movement of hydrophobic substances
What are the two types of transport proteins?
Channel proteins + carrier proteins
Channel Proteins
Type of transport protein. Form pores which transport according to size + charge
Carrier Proteins
Type of transport protein. Have binding sites where specific substances attach in order to be transported.
What do receptor proteins do?
Cause cellular respiration when specific molecules attach. Some act as gates on channel proteins.
What do recognition proteins do?
Act as I.D. tags on the cell structure and function in immune response. (Most are glycoproteins)
Cell membranes are ______ permeable. What does this mean?
Selectively permeable. It means that some substances can cross, others cannot. It is also much more selective than semi-permeable / permeable structures.
What are the two types of transport stuff uses to get across the cell membrane?
- Passive Transport
2. Energy-Required (Active) Transport
Passive transport does what? (concerning conc. gradient and energy)
Follows the concentration gradient (high to low) and does not require energy.
Active transport does what? (concerning conc. gradient and energy)
Functions regardless of concentration gradient and requires a gateway and energy (ATP)
(EX. sodium/potassium pump)
What are the 3 processes that use passive transport?
Diffusion, osmosis, and facilitated transport
What are the 3 processes that use active transport?
Active transport, exocytosis, and endocytosis.
What are the 3 principles of diffusion?
- Diffusion is the net movement of molecules down the concentration gradient (high to low)
- Does not move molecules rapidly or over long distances
- If no other process is involved, it will continue until equilibrium is reached.
What two substances can pass the cell membrane freely?
Oxygen gas (O2) and Carbon Dioxide (CO2)
What 5 things is rate of diffusion dependent on?
- Concentration gradient
- Size + shape of molecules
- Temperature
- Concentration (total # of molecules)
- Chemical properties
Which substances can diffuse through the phospholipid bilayer?
small lipid soluble molecules (ex. gases, ALCOHOL, etc.)
What is osmosis?
The diffusion of water from high to low concentration across the membrane through a pore.
What force causes the diffusion of water through a membrane (aka Osmosis)?
Osmotic Pressure
What is Hydrostatic Pressure?
The force created by the mass of water accumulating in the area of lower concentration (counterbalances osmotic pressure)
What does it mean when an environment is Hypotonic?
It is less concentrated than the cell (more water is present) so the cell gains water.
What does it mean when an environment is Hypertonic?
It is more concentrated than the cell (less water is present) so the cell loses water.
What does it mean when an environment is Isotonic?
Environment is equal to concentration of cell so no water is gained/lost.
Animal/Plant cell that is placed in a hypotonic solution (more water present than cell) will undergo ____/_____
Cytolysis in animal cells
Turgo Pressure in plant cells
Animal/Plant cell that is placed in a hypertonic solution (less water present than cell) will undergo ____/____
Crenation in animal cells
Plasmolysis in plant cells
What is another way to say Passive Transport?
Facilitated Transport
What is endo/exo-cytosis?
Cell eating(endocytosis) and pooping(exocytosis). An energy (ATP) required active process for moving large substances or large amount of substances in and out of the cell.
