Body Fluid Compartments Flashcards
List the concentrations of the major components of intracellular and extracellular fluid
Body is made up of 60% water (42 litres) 33% is extracellular 67% is intracellular 3.5 litres is blood plasma 10.5 litres is Interstital fluid
What lipid contributes to membrane fluidity the most?
Cholesterol
What are the main characteristics in membrane proteins?
They float in the bilayer
They are mainly glycoproteins
they provide structural channels (pores) for water soluble substances to pass through
Some are transporters to move substances against a concentration graditent
Some are receptors for water soluble chemicals
What are the charateristics of integral proteins?
These proteins lie within the bilayer snugly and usually require the entire membrane to be disrupted to remove from the bilayer
What are the characteristics of peripheral proteins?
Proteins that adhere only temporarily to the biological membrane with which they are associated.
Usually attached to integral membrane proteins, or penetrate the peripheral regions of the lipid bilayer.
Usually weakly bound and easily purified
What factors affect diffusion rates through cell membranes?
Concentration
Pressure
Electric potential
What examples of substances that can or cannot cross the lipid bilayer freely?
Can: O2, CO2, N2 (non polar/lipid soluble)
Cannot: Water, ions, glucose, urea (hydrophilic substances require help to cross lipid bilayer)
What measures the permeability of a substance and what is the unit that it’s measured in?
The permeability coefficient measures is measured in cm/sec
What is the membrane permeability equation and what do the variables mean?
P= (omega)RTk/a
P: membrane permeability omega: size of molecule and its viscosity R: gas constant T: temperature in Kelvin k: molecule resistance a: thickness of membrane
What type of diffusion occurs in channel and carrier proteins?
Channel proteins: simple diffusion
Carrier proteins: facilitated diffusion
Why don’t carrier proteins require energy?
Because its resting state has inherit energy in the protein and when it binds to the solute, it changes its shape and the energy is released to move the solute across the membrane.
