Biophysics

cholesterol/phospholipid ratio, the membrane potential, the types of phospholipids in the membrane, temperature, pH

the core of the membrane is hydrophobic and the surfaces are hydrophilic, they have a thickness of 5-7 nm, they are mainly composed of lipids and proteins but also carbohydrates, are antientropic barriers, contain cholesterol

represents a temperature-dependent membrane characteristic, is dependent on the amount of intramembrane cholesterol, represents the expression of a property of the biomembrane, fluidity, it is especially the expression of the movements of membrane phospholipids, it is the result of order and disorder in the membrane

role in maintaining intracellular pH, role in maintaining cellular ionic composition within certain limits, role in intercellular communication, role in maintaining cell volume, role in removing toxic substances from the cell

the intracytoplasmic domain is involved in signal transduction and receptor trafficking, the intracytoplasmic domain includes the area that participates in G protein activation, in the case of G protein-coupled receptors, the transmembrane domain usually includes a short chain of about 20 amino acids, the intracytoplasmic domain includes a phosphorylation zone, in the case of receptors with protein kinase activity, the extracellular domain includes the ligand binding site

ion channels present two conformational states, closed-open, for opening being required a stimulus, both membrane transporters and ion channels mediate facilitated diffusion, membrane transporters present two conformational states, closed-open, for opening being required a stimulus, both are passive transport systems, the rate of passage of ions is lower in the case of membrane transporters compared to ion channels

works by pairing with a receiver, shows reversibility, shows specificity of transported species, are integral membrane proteins, transports molecules in the direction of the chemical gradient

have specific blockers, shows ion selectivity, has two essential conformations (closed and open), the transport speed of ions is higher than in the case of transporters, has tissue specificity

the intracellular segment presents a signal transduction system, can be specifically blocked with tetrodotoxin (TTX), the transport speed of Na+ ions is of the order of picoSiemens, has two essential conformations (closed and open), has tissue specificity

the concentration of the transported molecule appears in the equation, the time in which the molecule is transported appears in the equation, establishes the factors on which the passive transport of a particle across the membrane depends, refers to the phenomenon of simple membrane diffusion, one of the parameters in the equation is S, the membrane surface area through which transport takes place

osmosis, simple diffusion, Donnan equilibrium, transport through ion channels, transport by carriers

are permeabilitate ridicată pentru oxigen și dioxid de carbon, represents an optimal environment for the functioning of molecules (enzymes, ion pumps, receptors), it is selectively permeable, allows water to pass through aquaporins, represents a delimitation of the intracellular compartment from the extracellular one

proton pump, H+/K+ ATP-ase, Ca2+ ATP-ase, Na+/K+ ATP-ase, Na+/K+ pump

field, protein G, protein kinase A, IP3, protein kinase C