Cells and Orgnellels Flashcards
(161 cards)
Cell membrane holds Cellular contents and are composed of what?
phospholipids, proteins, and cholesterol
What are phospholipids composed of?
glycerol backbone, one phosphate group, and two fatty acid tails
Phospholipids are _________ because they have polar and nonpolar parts, allowing then to form a lipid bilayer in an aqueous environment.
amphipathic
What is cholesterol composed of?
four hydrocarbon rings
Cholesterol is the precursor to ______ ______.
steroid hormomes
Cholesterols are ____ and regulate ____ ____
amphipathic; membrane fluidity
What are the two types of membrane proteins?
integral(transmemebrane protien), peripheral(surface protien)
Integral protiens transverse the entire membrane bilayer and so they must be ____?
Amphipathic
Integral protein ____ parts lie in the middle of the bilayer while the _____ parts extend out into the aqueous environment outside and inside the cell membrane.
nonpolar;polar
Function of membrane protiens
signaling and transport
Where are peripheral proteins found?
outside of the cell membrane
Peripheral proteins are generally ____
hydrophilic (water loving)
What are the functions of peripheral proteins?
receptor,signaling, adhesion
Protein receptors trigger ____ within the cell for signaling. However, if the protein receptor transmits a signal through the lipid bilayer it is considered an _____ protein.
secondary; integral protien
Drugs that bind to receptors can be considered either __ or __.
agonists; antagonists
Agonists
they are like party people they bind to receptors to activate a target
Antagonists
They are like Karens they bind to a receptior to prevent other molecules from binding and inhibits target activation
Adhesion
attaches cells to other things
Cellular Recognition
proteins that have carbohydrate(glycoprotiens) chains used to recognize other cells (sugar intenas)
What does the fluid mosaic model descibe
FLUID-how components that make up the cell membrane can move freely.
MOSAIC-how many structures the membrane contains
What affects the fluidity of a memebrane
Temp,cholesterol,degrees of saturation
how does temp affect membrane fluidity
high temperatures increase fluidity
low temperatures decrease fluidity
How does cholesterol affect membrane fluidity?
high temp cholesterol make membrande more rigid to prevent it from becoming too fluid.
low temp cholesterol makes the membrane more fluid to prevent it from becoming too ridgid and shattering
How do degrees of saturation affect membrane fluidity?
saturated fatty acids pack tight because they lack double bonds and thus are solid a room temp. unsaturated fatty acids have double bonds that doesnt allow tight packing and makes them fluid at room temp