Lecture 5: Cells and Tissues Flashcards
Integral proteins are found…
…embedded in the cell membrane.
The phospholipid bi-layer functions to…
…contain cell contents and separate them from the surrounding environment.
Transmembrane proteins…
…go all the way thru the membrane.
Peripheral proteins…
…are loosely associated with the membrane.
The ion channel acts to…
…allow specific ions to move thru pores.
Transporters…
…move specific substances across membrane by changing shape.
Receptors…
…recognize specific ligands and alter cell function in some way.
Describe the function of enzymes.
Enzymes catalyze reactions inside or outside the cell.
Cell ID markers…
…distinguish your cells from anyone else’s (except identical twins).
What do anchoring proteins (or linkers) do?
They anchor filaments in and outside to the plasma membrane and provide structure, stability, and shape.
What does selective permeability mean?
That some things can and can’t move in.
Describe the concentration (chemical) gradient.
It is when an uneven amount of dilutes move across the membrane.
Define the electrochemical gradient.
A difference in concentration and charge in the plasma membrane.
Describe active PM transport.
Solutes are moved against the gradient and use ATP.
Describe passive PM transport.
Solutes move down the gradient and no energy is used.
What is diffusion?
Movement across the membrane from high to low concentration.
Describe membrane/ion channel transport.
Ions move thru the channel from high to low and use no energy.
Define osmosis
Diffusion of H2O thru a specific protein channel.
Osmotic pressure is…
…pressure associated with osmosis because dilutes aren’t moving.
Facilitated diffusion
Selects ions to move thru based on size and charge
Ex: large and/or polar ions
Sodium potassium pump
Cell creates transporter protein to move Na out of cell against its gradient (using ATP), which causes the pump protein to change shape. It brings K in down the gradient.
Vesicles
Small sac that buds off the membrane
Endocytosis
Brings things into the cell
Receptor-mediated endocytosis
Bring in specific substances with a receptor
