Cell Physiology Flashcards
What is the basic fundamental units of animal life?
Cells
True or False: Ions are called electrolytes because they are able to conduct an electrical current in solution.
True
Give examples of a cation and an anion (1 each) found in body fluids.
Cation = Na^+ , K^+ , Ca^2+ , Mg^2+ , etc. Anion = Cl^- , I^- , OH^- , etc.
How is the acidity or alkalinity of a fluid determined? (NOT by using the pH scale.)
The concentration oh H+ relative to concentration of OH-
Describe the pH scale.
0 - 14: 7 = neutral, less than 7 = acidic (more H+) and greater than 7 = basic (more OH-)
Where is interstitial fluid found?
Between cells but outside of blood vessels.
Define selectively permeable (as pertaining to cell membranes).
Impermeable to some substances & freely permeable to others.
What 3 factors detemine whether or not molecules may pass into or out of cells by passive diffusion?
Molecule size, lipid solubility, and ionic charge.
Briefly explain how negative (less positive) charge inside of cells is maintained.
K+ diffuses out of cells more easily than Na+ goes back into cells via simple diffusion. Sodium-potassium only retrieves 2 K+ for every Na+ pumped out per ATP molecule used. Cytosolic proteins have slight negative charge.
Which of the following are all examples of passive transport processes?
a) diffusion, facilitated diffusion, exocytosis
b) diffusion, filtration, osmosis
c) facilitated diffusion, filtration, endocytosis
d) filtration, exocytosis, osmosis
b) diffusion, filtration, osmosis
What differentiates a passive membrane process from an active one?
Active processes require ATP; passive processes do not need energy to function.
List one passive membrane process and one active membrane process.
Passive = simple diffusion, facilitated diffusion, osmosis, filtration. Active = active transport, endocytosis (phagocytosis, pinocytosis), exocytosis
What is Intracellular fluid ( ICF ) ?
Water inside the cell.
Most of water in body.
What is Extracellular fluid ( ECF ) ?
Outside the cell.
Intravascular & lymphatic?
inside blood & lymphatic vessels.
Interstitial?
in tissues but outside of the vasculature.
What is more than one ion together called?
ionic compound.
Ex: salt = composed of oppositely charged ions that separate when mixed in water.
What are acids & bases?
Acids = release hydrogen ions (H+) Bases = release hydroxyl ions (OH-)
What is the flow of fluid and nutrients into and out of called regulated by?
Plasma membrane
What is Diffusion?
Kinetic energy - increases w/ higher temp
Movement from a higher to lower concentration - concentration gradient
Size - small molecules like H2O pass easily
Lipid solubility - dissolved gases, alcohols, steroids easily pass through cell’s lipid bilayer
Charged ions - specialized protein pores called channels selectively let certain ions pass
Explain Facilitated Diffusion
Movement of some larger and/or nonsoluble molecules with the asst. of a protein carrier located in lipid bilayer
Binding of the extracellular molecule to membrane protein causes protein to change shape & allow molecule to pass into cell.
Glucose is too large to rely on simple diffusion so it must enter cell via a protein carrier.
Protein is limited by number of carrier proteins available for binding.
What is osmosis?
passive movement of water through a semipermeable membrane from a dilute to a more concentrated environment.
Occurs to achieve same concentration of solution on both sides of the membrane = concentration equilibrium.
Force moving water across the membrane = osmotic pressure.
What is Concentration Gradient?
same concentration of solution on both sides of the membrane.
What is Osmotic Pressure?
force of moving water across the membrane.
