Chapter 2 Study Questions (Part 3) Flashcards
what is the energy source for motor proteins and what determines the direction they move in?
energy source: hydrolyze ATP
direction: it’s complicated
what is the function of motor proteins?
hydrolyze ATP and physically move things along in the cell
what is the function of tight junctions?
maintain stable/separate environments.
prevent leaking between cells, aka prevent substances from passing between cells.
what is the function of gap junctions?
open and close to regulate the movement of molecules between cells as a form of communication, sending ions across.
what is the function of desmosomes? where are they found?
“spot rivets”
bind cells together for strength
found in tissues subject to mechanical stress (stomach, skin, utrs)
what is the benefit of having cholesterol present in a cell membrane?
helps membrane hold its form even though it’s growing and shrinking with thermal energy. decrease the permeability of membrane to water
what are the three types of cytoskeletal protein fibers ?
microfilaments
intermediate filaments
microtubules
are peptide bonds that are found in proteins susceptible to proteases?
yes! protease breaks up peptide bonds!
are disulfide bonds that are found in proteins susceptible to proteases?
no. protease only breaks up peptide bonds
what bonds involved in protein structure are affected by physiologic pH?
all but covalent
where are tight junctions found?
between epi/endo-thelial cells
what motor protein operates along actin?
myosin
what are the three motor proteins that we talked about in class?
myosin, kinesin, dynein
what motor protein operates along microtubules?
kinesin and dynein
what direction does kinesin move in? along what structure?
negative to positive along the microtubules
