Proteins Flashcards
What is facilitated diffusion?
Passive transport aided by proteins
Why do proteins facilitate transport?
transport proteins speed up the passive movement of the molecules across the membrane - NO ENERGY
What is a channel protein?
A channel protein is an arrangement of amino acids that embeds in the cell membrane, providing a hydrophilic passageway for water and small, polar ions. Like all transport proteins, each channel protein has a size and shape which excludes all but the most specific molecules.
What is a carrier protein
V shaped, they have a hinge-like mechanism that open up, get in and open up which allows the solute out
What is a transporter protein?
Proteins that have the right shape, so they can open under specific conditions to move potassium/sodium/water along the con. gradient (hydrophilic substances)
What do aquaporins and ion channels do?
Open and close at the response of stimulus (gated channels)
What do carrier/transport proteins do?
They bind to molecules and change the shape to shuttle them across the membrane
Why do transmembrane proteins have pores?
They form pores through which ions and molecules can pass through/not –> control
What are the different types of ion channels?
Potassium ion channels and aquaporins
DIFFUSION (proteins)
Hydrophobic molecules, small uncharged polar molecule can diffuse
FACILITATED DIFFUSION
Hydrophilic substances diffuse through membranes with the assistance of transport proteins either channel/carrier
Active transport with protein, what does it do?
The use of a transporter - against con. As it has the ability to harness the energy released when ATP breaks
Which modes of transport require a protein?
Active and facilitated transport –> use proteins to mediate across the cell membrane
When does bulk transport occur?
Exocytosis and endocytosis
Endo
(mass coming in)
