MCAT Chem

Question 1

electrolytic cell

Answer 1

when battery is charging, it functions as an electrolytic cell because an external potential drives the REDOX rxn to proceed in a non-spontaneous direction

Question 2

galvanic cells + types of it

Answer 2

galvanic cells converts chemical energy to electrical energy in spontaneous redox rxn. Ecell is positive

Concentration cell: electrons flow from lower concentration half-cell to higher half-cell, thus generating a potential.

Fuel Cell: reactants are continuously supplied at the anode and cathode as products are continuously removed from the system.

Question 3

electrolytic + galvanic cells

Answer 3

oxidation occurs at anode and reduction occurs at cathode

Question 4

action potential depolarization

Answer 4

resting membrane potential maintained at -70mV. Voltage-gated Na+ channels are deactivated (closed) at rest, but when a stimulus reaches a threshold level (-55mV), the activation gates open and Na+ ions enter the cell

Question 5

action potential repolarization

Answer 5

as membrane potential reaches +30mV, the inactivation gates of Na+ channels close, preventing re-entry of Na+ ions and K+ channels are opened. The Na+ channel inactivation gates remain closed while the cell repolarizes

Question 6

action potential hyperpolarization

Answer 6

Membrane potential becomes slightly more negative than resting potential, until K+ concentration reaches equilibrium. The resting membrane potential is fully restored when K+ channels close. Na+ channels return to a deactivated (closed) state during this time

Question 7

order of large intestine

Answer 7

cecum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum

Question 8

gut flora

Answer 8

bacterial species that aid digestive processes by processing undigestable foods into molecules that can be absorbed by the body and can synthesize certain vitamins