importance
The membrane allows certain substances to do what to maintain the balance
go in and out
It consists of a phospholipid bilayer with interspersed proteins, cholesterol, and carbohydrates.
works to reach homeostasis
pasive
requires energy to work against homeostasis
pumps
How does osmosis differ from simple diffusion
Osmosis is the passive diffusion of water across a selectively permeable membrane.
3 types of passive transport
diffusion, facilitated diffusion,osmosis
What is simple diffusion and what types of molecules use it?
Simple diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration (down their concentration gradient).
Does passive require energy?
no
membrane changes shape to grab large particles+bring into cell from??
endocytosis
What is facilitated diffusion, and which substances rely on it?
It is a form of passive transport (requiring no ATP) used for large, polar, or charged molecules (like glucose, amino acids, and ions)
3 types of active transport
pumps, endocytosis, exocytosis
How do larger or charged molecules cross the membrane?
They use facilitated diffusion, a form of passive transport that requires specialized transmembrane proteins.
does it work with the concentration gradient
yes
cell membrane changes shape to respond to particles from the cell from?
exocytosis
How does active transport differ from passive transport
Active transport moves substances against their concentration gradient (from low to high concentration).
what does the active transports do (the pumps)
Moves molecules or ions against their concentration gradient (from low to high). This requires ATP and utilizes specialized carrier proteins.
What is osmosis, and how does it affect cells?
Osmosis is the specific term for the diffusion of water across a selectively permeable membrane.
diffusion of water specifically
osmosis
what makes particals against concentration low to high
pumps
How do extremely large particles, fluids, or entire cells enter and exit the cell?
Large-scale transport occurs via vesicles formed from the cell membrane
What does facilitated diffusion do
Uses specific transmembrane proteins (channel and carrier proteins) to assist large or polar molecules (like glucose and ions) across the membrane without using energy.
What is active transport, and why is it necessary?
Active transport is the movement of molecules or ions against their concentration gradient
small particles pass directly through
diffusion
for large molecule that cannot cross the membrane.
exocytosis
What types of molecules cross the cell membrane via simple diffusion, and how do they move?
Small, nonpolar molecules like o2 and co2 pass directly through the phospholipid bilayer without requiring energy