Cell Physiology Flashcards
Cells have the ability to:
o Metabolize
o Digest food
o Dispose of wastes
o Reproduce
o Grow
o Move
o Respond to a stimulus
dissolving medium present in the larger quantity; the body’s main solvent is water
solvent
homogeneous mixture of two or more components
Solution
components in smaller quantities within a solution
solutes
Nucleoplasm and cytosol
Solution containing gases, nutrients, and salts dissolved in water
Intracellular fluid
Fluid on the exterior of the cell
Extracellular fluid (interstitial fluid)
Contains thousands of ingredients, such as nutrients, hormones, neurotransmitters, salts, waste products
Extracellular fluid (interstitial fluid)
is a selectively permeable barrier
plasma membrane
Some materials can pass through, while others are excluded
For example:
Nutrients can enter the cell
Undesirable substances are kept out
selectively permeable barrier
Two basic methods of transport
passive processes
active processes
substances are transported across the membrane without any input from the cell
passive processes
the cell provides the metabolic energy (ATP) to drive the transport process
active processes
diffusion and filtration
passive processes
Molecule movement is from high concentration to low concentration, down a concentration gradient
diffusion
Kinetic energy (energy of motion) causes the molecules to move about randomly
diffusion
Particles tend to distribute themselves evenly within a solution
diffusion
__________ and ________ affect the speed of diffusion
Size of the molecule temperature
___________ (energy of motion) causes the molecules to move about randomly
Kinetic energy
Molecules will move by diffusion if:
- The molecules are small enough to pass through the membrane’s pores (channels formed by membrane proteins)
- The molecules are lipid-soluble
- The molecules are assisted by a membrane carrier
are lipid soluble
molecules
channels formed by membrane proteins
membrane’s pores
types of diffusion (3)
simple diffusion
osmosis
facilitated diffusion
The molecules are small enough to pass through the __________________
membrane’s pores
a type of diffusion that is an unassisted process
simple diffusion
in this type of diffusion solutes are lipid-soluble or small enough to pass through membrane pores
simple diffusion