Flashcards in Cytoskeletons in the closet & Plasma Membrrraaaiiiins Deck (46):
A rich patchwork tapestry of proteins makes up the...
The cytoskeleton has 2 functions:
1. Maintaining 3d shape in animals & plants (of cytoskeleton)
2. Moving things within the cell (cellular trafficking)
3 Types of Proteins that makeup the cytoskeleton:
Microtubules - Vesicle Highways
Actin - Maintain 3D shape
Keratin - anchor organelles
Of the 3 proteins, which is the largest?
5 functions of the plasma membrane:
To cross without a channel, a molecule must be __________ & ________.
Small & nonpolar
What do we know can cross?
O2, (CO2, H2O)
This crossing of the membrane is called...
Movement down a concentration gradient...
Facilitated diffusion relies on a:
T/F Facilitated diffusion uses ATP.
Movement AGAINST a concentration gradient:
Active Transport utilizes a:
T/F ATP is required for Active Transport.
How does the membrane communicate?
Carries chemical messages. SIGNAL TRANSDUCTION.
How does the membrane make chemical reactions?
Enzymes embedded in membranes
The membrane can recognize......
Eggs & Sperm of own species
Two ways the cell membrane adhesions?
The membrane is considered a _______ structure.
FLUID. Bilayer is free to migrate.
In addition to being fluid, the membrane acts as a:
Barrier, keeping things in or out
T/F The membrane has variable fluidity.
Why is it considered variable?
Unsaturated fatty acids!
When saturated - tight
When unsaturated - loosey goosey
Cholesterol ________ fluidity.
In Northern climates?
Increased cholesterol, increased unsaturation.
In southern climates?
Similar to cholesterol but in bacteria cell membranes?
Cholesterol prevents ________ in the plasma membrane.
The passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration.
Diffusion is dependent on....
Gradients can be:
Chemical or Electric
(Most often combo of both)
Molecules will diffuse until they reach:
For simple diffusion molecule must be:
Small & non-polar
Why can diffusion happen?
Membrane is semi-permeable
What one compound can't cross & no transporter for?
Movement of a solvent through a semi-permeable membrane into a solution with higher solute concentration.
In osmosis, it always goes from ___ to ____.
Low to high
The total concentration of solutes =
Low solute concentration =
High H20, Hyposmotic
High solute concentration =
Low H20, Hyperosmotic
The H20 will move...
Down its gradient from high h20 to low h20
The ability of a solution to cause a cell to gain or lose water.
Solute = Solute
Isotonic - Normal/Flaccid
Solute > Solute
Hypotonic - Lysed/Turgid
Solute < Solute
Hypertonic - Shrink/Plasmolyse
Prokaryotes have membrane bound organelles. T/F?
FALSE - just internal membranes which fold in on themselves.