Movement of Molecules Flashcards
What % of body weight is water for males and females?
60% males
55% females
What % of fluids are intracellular fluid and extracellular fluid?
2/3 intracellular fluid
1/3 extracellular fluid
What % of extracellular fluid is interstitual fluid and plasma?
80% extracellular fluid
20% plasma
Order composition of fluids from largest to smallest
- 2/3 of body weight is fluids
- 60% of ICF
- 80% is interstitual fluid
What is a solute?
anything that is dissolved in a solvent
What is a solvent?
anything that dissolves other substances
What are electrolytes?
charged ions that dissociate in water (break up)
eg. sodium, pottasiumm
What are some examples of non-electrolytes?
Glucose, lipids, urea
What are 2 passive processes?
diffusion and ozmosis
What is an example of a primary active process?
sodium-pottasium pump
What is an example of secondary active transport?
symporters and anti-porters (indirectly uses ATP)
What is an example of vesicular active transport?
endocytosis and exocytosis
What is the chemical sign for pottasium and sodium?
Pottasium - K+
Sodium - Na+
Is there higher or lower concentration of sodium found outside the cells?
Higher
How many sodium ions are moved out of the cell for every potassium ions moved in?
3 sodium out, for 2 potassium in
What is the difference between an antiporter and a symporter?
Antiporter - can move molecule in different direction
Symporter - can move molecule in same direction
What is bulk phase endocytosis?
cell drinking, tiny droplets of ECF are engulfed
What does an acid do?
releases/donates hydrogen ions when in a solution
What does a base do?
accepts/removes hydrogen ions from a solution
What is an example of a base and an acid?
Base - bicarbonate ion
Acid - hydrochloric acid
What is acidosis?
excess hydrogen ions in the body (pH has dropped)
What does BAD stand for?
“Bases accept, acids donate?
On a pH scale what does below 7 indicate?
acidic, lots of hydrogen ions
On a pH scale what does above 7 indicate?
basic (alkaline), less hydrogen ions
What determines how acidic/basic a solution is?
the concentration of free hydrogen ions in the body
What is the plasma fluid pH?
7.35 - 7.45
What is the function of a buffer system?
a solution that will resist changes in pH when a strong acid/base is added, to maintain pH within narrow limit
Either:
- bind to extra free H+ ions
- release more free H+ ions
What is an example of a chemical buffer?
Bicarbonate system
What is the chemical equation of the bicarbonate system?
carbonate acid -> bicarbonate ion + hydrogen
What is a ligand?
chemical that binds to something
What is a ligand-gated channel?
needs ligand to open
What is a mechanically gated channel?
closed until mechanical stimulus
deformation of cell, heat, pressure
What is a voltage-gated channel?
closed until voltage alters the electrical charge of cell
What is a leakage channel?
Always open, ions move down their concentration gradien
What are some factors that influence rate of diffusion?
- steepness of concentration gradient
- temperature
- mass of substance
- surface area
- distance
What is simple diffusion?
passive process where substances can move freely through the lipid bi-layer of the plasma membrane with the help of protein channels or carriers
eg. gases, non-polar hydrophobic substance, small. molecules
What is facilitated diffusion?
passive process where molecules that are too polar or highly charged, move through the bilayer of the plasma membrane via a channel or carrier protein
2 types:
- channel-mediated facilitated diffusion
- carrier-mediated facilitated diffuion
What are the 2 types of diffusion?
simple and facilitated
What is ozmosis?
the movement of water across the plasma membrane from a high concentration of water, to a low concentration of water
What is hydrostatic pressure?
water’s weight forcing it back
What is osmotic pressure?
the amount of pressure needing to restore to the starting condition
What is tonicity?
The ability of solution to change the shape of a cell (because of the movement of water)
What is osmolarity?
the number of solute particles in a solution
What is hypertonic solution?
relatively high concentration of non-permeable solutes outside of the cell
- creation (cell shrinks)
What is hypotonic solution?
relatively low concentration of non-permeable solutes outside of the cell
- lysis (cell bursts)
What is an isotonic solution
equal concentration of non-permeable solutes in the ICF and ECF
(no net movement of water)
What does resting membrane potential mean?
a cell’s difference in charge between outside and inside areas, at resting state
What are some factors that affect RMP?
- uneven distribution of ions across cell membrane
- difference in leak channels
- more potassium leak channels than sodium
Is the inside of cell positive or negative at resting state
Negative
What is the RMP?
-70mV
Do electrolytes or non-electrolytes dissociate in water?
Electrolytes
Explain the process of sodium-potassium ATPase
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