Sloviter Flashcards
Liposomes
Vesicles that are used to carry vaccines, drugs, enzymes, or other substances in their aqueous core
Amino acid constituents and disease
The amino acid constitution of the protein will determine not only its 3d shape but its resistant to changing its conformation and then you can start to see in terms of disease that a single amino acid substitution will completely change the amino acid
- Steric hindrance
- Electrochemical attraction or repulsion
- Cross-linking (S-S cysteine)
Ionotropic membrane receptors
FAST
-Ligand-gated channels
-Voltage-gated channels
Glutamate (both ionotropic and metabotropic)
-GABA-A
-Acetylcholine– nicotinic
Metabotropic membrane receptors
G-protein-coupled
- Acetycholine–muscarinic
- Glutamate
- GABA-B
Primary active transport
requires a direct input of metabolic energy
Secondary active transport
Utilizes an indirect input of metabolic energy
Receptor agonist
any endogenous or exogenous receptor ligand that binds to a receptor’s active site (as opposed to an allosteric modulatory site) and evokes a biological response.
Receptor antagonist
any endogenous or exogenous receptor ligand that binds to a receptor’s active site, but does not evoke a biological response.
-Note that antagonists can bind with great affinity; they just don’t produce the biological response
Partial agonist/antagonist
relatively weak agonist that can act as an “antagonist” when combined with a strong agonist
-bus vs ferrari
Main factors affecting the movement of molecules across membranes and absorption of drugs into the blood are:
- Concentration gradient
- Lipid/water solubility (charged molecules don’t cross membrane passively)
- Absorptive surface area available
- Rate of blood flow through the tissue (this powerfully affects the concentration gradient)
- Thickness of the membrane
Digitalis
Poisons the Na+K+ ATPase
Permeability of Na+, K+ in cell
Cell membranes are relatively permeable to K+ (K+ channels are leaky), but are impermeable to Na+
Fick’s Law of diffusion
The rate of diffusion across a membrane is directly proportional to the concentration gradient of the substance, and the surface area available, and is inversely related to the thickness of the membrane
Insulin the body vs Insulin in the brain
Body: The facilitated transporter, glucose transport, sits inside the cell cytoplasm. When glucose is high in the blood, insulin released from the pancreas binds to the insulin receptor.
Insulin acts as an agonist – insulin receptors autophosphorylated
Then Glut4 is now inserted into cell and glucose enters the cell
Brain: Brain has unlimited glucose entry that is not dependent on insulin. Blood vessels in brain are different than blood vessels in body
Sodium regulation
Major principle in biology/medicine
-sodium is kept in high concentration extracellularly by the Na+K+ ATPase
High concentration of extracellular sodium, and the impermeability of the membrane to sodium, makes it a major driving force in many functions
