Chapters 7, 8, and 9 Flashcards
What does it mean when something is amphipatic?
Has hydrophobic and hydrophilic parts
What is the difference between peripheral and integral proteins?
Peripheral proteins are bound to the surface of the membrane, while integral proteins penetrate the hydrophobic core
Are transmembranes peripheral or integral proteins and why?
Integral proteins because they are on both sides of the membrane
What can move through or across the membrane, and how quickly?
Hydrophobic molecules rapidly and hydrophilic molecules need a process
What is diffusion?
The tendency for molecules to spread out evenly into the available space
What is a concentration gradient?
The gradual change in the concentration of solutes in a solution as a function of distance through a solution
What is required when a molecule goes against a concentration gradient?
Energy and a protein
What is the difference between passive and active transport?
Passive requires no energy to be used by the cell, while active transport requires energy (usually in the form of ATP hydrolysis) to move substances against concentration gradients
What is osmosis?
The diffusion of water across a selectively permeable membrane
What does an isotonic solution do?
Solute concentration is the same as that outside the cell. There is no net water movement across the plasma membrane
What does a hypotonic solution do?
Solute concentration is less than that outside of the cell. The cell gains water
What does a hypertonic solution do?
Solute concentration is greater than that outside the cell. The cell looses water
What do cells look like when they are in an isotonic, hypertonic, and hypotonic solution?
Isotonic: normal
Hypertonic: shriveled
Hypotonic: bloated (lysed)
What is osmoregulation
The control of solute concentrations and water balance across the membrane
What are aquaporins?
Transmembrane proteins that regulate the movement of water in/out of cell
What is facilitated diffusion?
Proteins speed the passive movement of molecules across the plasma membrane
What are transport proteins?
Proteins that speed passive movement of molecules across the plasma membrane
What are channel proteins?
A transport protein that provide molecules a corridor to cross the membrane (open door)
What are carrier proteins?
A transport protein that changes shape that brings the binding site across the membrane
What is active transport?
Requires energy (usually ATP hydrolysis) to move substances against their concentration gradient