Unit 2 Flashcards
What are the components of water potential?
Pressure potential and osmotic potential or solute potential.
What is water potential?
It is the voltage across a membrane. It measures the tendency of water to diffuse from one compartment to another.
How can you use water potential to predict the movement of water?
Water moves from an area of higher water potential to an area of lower water potential.
What’s the difference between passive transport and active transport?
Passive transport doesn’t use energy and more solutes along their concentration gradients. Its spontaneous and random.
Active transport requires energy in order to more solutes against their gradients.
What are the types of passive transport?
Diffusion and facilitated diffusion
What is diffusion and what kinds of molecules does it move?
- movement of molecules from high to low concentration
- Allows small nonpolar molecules to pass through the membrane freely.
- Water is polar but can pass because it is so small.
What is facilitated diffusion and what kinds of molecules does it move?
Allows polar, hydrophilic molecules to pass through the membrane through the use of transport proteins.
How are facilitated diffusion and diffusion similar?
Don’t require energy to move molecules. Move them down their concentration gradients. High to low concentration.
How are diffusion and facilitated diffusion different?
Diffusion allows small nonpolar molecules through without help. Facilitated diffusion uses proteins that only allow a specific protein through.
What are the types of proteins that aid in facilitated diffusion?
Carrier proteins and channel proteins
What do channel proteins do?
Provide corridors that allow a specific molecule or ion through.
What are aquaporins?
Channel proteins that aid in the diffusion of water
What do carrier proteins do?
Bind to molecules, change shape, and bring the molecule across. For specific molecules.
How do particles move in relation to their concentration gradients?
They move from areas of high concentration to areas of low concentration
What might happen to a cell if aquaporins are added to its cell membrane?
Would let in more water, quicker. Would reach dynamic equilibrium quicker.
What would happen to a cell if aquaporins are removed from the cell membrane?
Wouldn’t take in water as quickly. Would take longer to reach dynamic equilibrium.
What are the parts of a cell membrane?
- lipid bilayer (amphipathic phospholipids)
- proteins, aren’t randomly distributed, floating in the bilayer
- carbohydrates on the surface
- cholesterol in the bilayer
What is the structure of the lipid bilayer of the cell membrane?
Phospholipids that are held together by weak hydrophobic interactions.
Where are the proteins in the cell membrane? (Includes types of proteins)
Clustered in groups, determine the membrane’s function
- peripheral proteins, on the surface
- integral proteins, penetrate the hydrophobic core
- transmembrane proteins, Integral proteins that down the membrane
What are the functions of proteins on the cell membranes?
Cell to cell recognition, intercellular joining, transport, structure, enzymatic activity, signal transduction