Exam 2 Flashcards
(29 cards)
Which part of the endoplasmic reticulum is responsible for protein synthesis?
Rough ER
Which part of the endoplasmic reticulum is responsible for glycoprotein production?
Rough ER
What does the cytoskeleton do?
It supports the cell’s shape & hold organelles in fixed locations
What are the 3 main types cytoskeletal fibers?
Actin filaments (microfilmants), intermediate filaments, & microtubules
How is the cytoskeleton used in muscles?
Actin are used to contract muscles.
What is the space between the membranes of the mitochondria called?
The intermembrane space
What is a layer of the internal membrane of a mitochondrion called?
A crista
What is the extracellular matrix made of?
glycolipids
What does the centrosome do?
It helps with cell division
How can cells recognize each other?
surface markers
What is cadherin?
A Ca(2+)-dependent protein that is used to form adherens junctions, a type of adhesive junction, which are used to hold cells together.
What powers passive transport?
Concentration gradients
What are the 4 components of cellular membranes?
Phospholipid bilayer, transmembrane proteins, interior protein network, & cell-surface markers
What is osmotic pressure?
The tendency for water to cross a semi permeable membrane
What shape does a transmembrane domain need to be?
Either α-helix or β-pleated sheet, but usually α-helix
How are carrier proteins categorized based on which directions they can carry multiple molecules?
Uniporters (one molecule at a time), Symporters (two molecules, same direction), Antiporters (two molecules, opposite directions)
What are the 3 types of passive transport?
Simple diffusion, facilitated diffusion, osmosis
What is it called when a channel protein can close in response to stimulus?
A gated channel
How does the rate at which transport can happen differ between simple diffusion & facilitated diffusion?
With simple diffusion the rate increases linearly with concentration, but with facilitated diffusion, all carrier proteins can be occupied if the concentration is too high, meaning that there is a maximum rate. This is called saturation.
Why is active transport used?
To move molecules against a concentration gradient
Why do ions need facilitated transport?
They are charged, so the non-polar, hydrophobic interior of the membrane repels them.
Which direction does the sodium-potassium pump move sodium?
Out of the cell
Which direction does the sodium-potassium pump move potassium?
into the cell
What does phagocytosis mean?
“Eating cell.” It is a means of endocytosis for consuming solids
