membrane articles
What are the fast electrical signals that relay information through the nervous system called?
What is the typical value for a neuron's resting membrane potential?
What molecular machine is primarily responsible for establishing the steep concentration gradients for $ ext{Na}^+$ and $ ext{K}^+$?
What is the critical voltage level that must be reached to cause an action potential to fire?
Where do the initial graded potentials summate to determine if the threshold is met?
Which channels are the first to respond and open rapidly upon reaching the threshold voltage?
What process is responsible for the rapid, positive spike in membrane potential during the rising phase of the action potential?
What event causes the membrane potential to drive back down toward the resting level during repolarization?
What characteristic of sodium channels ensures the action potential moves only forward down an axon?
In myelinated axons, what process allows the signal to travel faster by 'jumping' along the axon?
What is the term for the delicate internal balance that the cell membrane's regulation ensures is maintained?
How do phospholipids spontaneously arrange themselves in an aqueous environment due to their amphipathic nature?
What fundamental energy input is required for passive transport processes?
Which molecules typically cross the lipid bilayer directly through simple diffusion?
What occurs when a cell is placed in a hypertonic solution?
Why do essential substances like sugars and amino acids often require facilitated diffusion?
What mechanism do channel proteins utilize to move specific ions across the membrane quickly?
What phenomenon limits the transport rate in facilitated diffusion if the concentration of the transported substance becomes extremely high?
What is the direct energy source coupled to the movement of a substance against its gradient in primary active transport?
According to the stoichiometry of the sodium-potassium pump, how many ions of each type are moved per ATP molecule used?
In secondary active transport (co-transport), what is the source of energy driving the uphill movement of one substance?
What fundamentally drives the movement of water across a barrier during osmosis?
What specific type of membrane is required for osmotic pressure to manifest?
How is the actual osmotic pressure (Π) defined in relation to external force?
What is identified as the primary driving force behind the flow of the solvent during osmosis?
Which mathematical law serves as an analogy for modeling osmotic pressure in its basic form?
What does the molar concentration (M) variable represent in the basic van't Hoff equation ($ p = MRT$)?
What classification is given to osmotic pressure because its magnitude depends only on the count of particles, not their type?
What term is introduced in the modified van't Hoff equation ($ p = iMRT$) to account for substances that break apart in solution?
For sodium chloride ($ ext{NaCl}$), which dissociates into two ions, what is its theoretical van't Hoff factor ($i$)?