Osmosis Flashcards
active transport
the movement of ions/molecules across a cell membrane into a region of higher concentration assisted my enzymes (require energy)
passive transport
movement of ions/atoms across a cell membranes W/O the need of energy input
diffusion
results in the movement of a substance from a region where it is more concentrated to where it’s less concentrated
osmosis
the diffusion of free water molecules across a selectively permeable membrane
facilitated diffusion
the passage of molecules/ions down their gradient across a membrane w assistance from transport proteins
exocytosis
the cellular secretion of molecules by the fusion of vesicles
endocytosis
cellular uptake of biological molecules and matter through the fusion of vesticles
phagocytosis
a type of endocytosis, large substances & small organisms are taken up by a cell. carried out by some protists & immune cells of amimals
pinocytosis
a type of endocytosis, where the cell ingests extracellular fluid and it’s dissolved solutes
hypotonic
referring to a solution that, when surrounding a cell wall, will cause the cell to take up water
hypertonic
cause the cell go loose water
isotonic
causes no net movement of water into or out of the cell
contractile vacuoles
A membrane sac that helps move excess water out of certain freshwater protists
amphipathetic
having a hydrophilic & hydrophobic region
What is the cell membrane primarily made up of? (3)
- phospholipids
- cholesterol
- proteins
the head of a phosphate molecule is what?
hydrophilic
the two tails of a fatty acid (phospholipid) are wjat?
hydrophobic
What is cholesterol ?
A type of steroid which is helpful in regulating molecules entering and exiting the cell
What are integral proteins helpful for?
Transporting large molecules like glue close across the membrane
Definition of polar
Means that electrons are not evenly distributed making one side more positively or negatively charged another
Definition of non-polar
That electrons are evenly distributed so the molecule is evenly charged across the surface
What are peripheral proteins
They don’t extend across the membrane, and can be attached to the ends of integral proteins
What are the three main factors that influence cell membrane fluidity?
Temperature, Cholesterol, saturated and unsaturated fatty acid’s
What would happen without cholesterol?
The phospholipids in your cells will start to get closer once cold making it difficult for gases to pass-through, or separate from each other when hot
Can small nonpolar molecules pass through the lipid bilayer easily?
Yes they can squeeze through and don’t need proteins for transport and can diffuse across quickly
Can small polar molecules, example: water, pass through the lipid Byler?
It’s more difficult because the Byler is hydrophobic tails so it won’t be easy without help and it will happen at a slower pace
Can large nonpolar molecules pass through the bilayer?
They can pass through but it will be slow
Can large polar molecules pass through the bilayer?
This makes it too difficult to pass through the region without help
what is cell eating?
phagocytosis
what is cell drinking
pinocytosis
extracellular
fluid surrounding a cell
What is a membrane that allows certain molecules to pass through it?
semi permeable
What does the water potential of pure water equal
Zero
A parameciums contractile vacuole is an example of?
paramecium using active transport to pump out water
Why might energy be needed for active transport?
Ions move against a gradient
The movement from high to low concentration is what
Diffusion
Stomata opens in plant cells when guard cells?
Swell because they gain potassium which brings water to the cell
What happens when the stomata closes?
The plants will wilt because they cant take in CO2
