Unit 2 exam review Flashcards
(139 cards)
Explain the fluid mosaic model
It is membranes that consist of a bilayer of phospholipids in which globular proteins are inserted.
What are globular proteins?
They are spherical shaped proteins.
List the 4 components of the cell membrane.
- Phospholipid bilayer 2. Transmembrane proteins 3. Interior protein network 4. Cell surface markers. (They tell the cell what to do)
What organic macromolecule is cholesterol?
It is a lipid.
Are phospholipids solid or fluid? Also explain phospholipids.
They are fluid. Individual phospholipids and unanchored proteins can move freely through the membrane. Saturated fatty acids make membrane more fluid than unsaturated fatty acids. Also warmer temperatures make it more fluid than cooler temps.
Name the 6 membrane protein functions.
- Transporters 2. enzymes 3. cell surface receptors 4. cell surface identity markers 5. cell to cell adhesion proteins 6. attachments to the cytoskeleton
List 2 facts about integral membrane proteins
They span the lipid bilayer or the transmembrane proteins. Also they are nonpolar domains so they are hydrophobic AA and are embedded in the hydrophobic regions of the lipid bilayer.
What do transmembrane domains do?
They span the lipid bilayer and they are a region of protein containing hydrophobic AA. Additionally, 7 is common.
What can Beta sheets form?
They can form a Beta barrel which is a cylinder.
What do Beta barrel do?
They regulate what goes in the cell.
Is passive or active transport diffusion?
It is passive.
What do channel proteins do?
They allow polar molecules to pass through
What do carrier proteins do?
They bind to a specific molecule and change shape so they can move through the pore and release the molecule.
What are the 2 types of channel proteins and what are they?
- ion channels, they allow the passage of ions that are associated with water. 2. Gated channels, they open of close in response to chemical or electrical stimulus(potential energy)
What is aquaporins?
It is water pores where osmosis moves water through towards hypertonic solution.
What are 2 things that active transport require?
It requires ATP or energy and it requires a specific carrier.
What three things do carrier proteins use in active transport?
- Uniporters, moves one molecule at a time 2. Symporters, moves 2 molecules at a times in the same direction. Usually one with active transport and the other with passive transport 3. Antiporters, they move 2 molecules in opposite directions.
Describe the Sodium-potassium (Na+-K+) pump.
It uses ATP, and it uses an antiporter. Sodium out, potassium in
What is coupled transport?
It is an active transport, uses energy released when a molecule moves by diffusion to supply energy for active transport. A symporter is used.
What are the three parts of endocytosis? Name and explain them
- Phagocytosis the cell takes in particular matter2. Pinocytosis the cell takes in fluid i.e. water. 3. Receptor-meditated endocytosis specific molecules are taken in after they bind to a receptor
What are three things to know about exocytosis?
- The vesicles fuse with the membrane and release their contents to the exterior. 2. used in plants to export cell wall material. 3. used in animals.
What is freeze fracturing?
It is a technique that separates the layers and reveals the membrane proteins using a scanning electron microscope (SEM).
What are photons associated with?
Light energy
What are two types of energy, and what do they do?
Kinetic energy, it is the energy in motion. Potential energy, it is the stored energy.