BMS02-1008 - Movement of Ions and Molecules in the body

Question	Answer
What is the approximate ionic concentration inside living cells vs. Extracellular fluid for Na+, K+, Ca2+, and Cl-?	Intracellular/Extracellular Na+: 10/140 K+140/4 Cl-: 4/140 Ca2+: 10^-3, 2.5
How do the following mass through the cell membrane: 1. Gases 2. Nonpolar/small uncharged polar 3. Ions 4. Larger molecules (eg. glucose)	1. Passive diffusion 2. Passive diffusion 3. Via channels/pumps 4. Channels/pumps
What are 3 features of the cell membrane?	1. Selective barrier (nutrients in, waste out) 2. Phospholipid bilayer 3. Fluid and self-sealing for endo/exocytosis
Water soluble is hydro... Water insoluble is hydro...	Hydrophilic, polar Hydrophobic, non polar
Simple diffusion (passive down a gradient) can occur through which two ways?	1. Direct through membrane 2. Through channels
What are the two types of active transport? (moves against gradient)	1. Antiport (eg. 3Na+ out /2K+ in ATPase 2. Symport (with a molecule moving passive down its gradient) (eg. Na+ with sugar/amino acids)
How is the osmotic gradient maintained by cells?	Na+/K+ pump maintains a much higher extracellular [Na+] compared to intracelluar. The membrane is relatively impermeable to Na+. As a result, if an increase in intracellular concentration arises (due to proteins etc. entering), the Na+ outside allows the osmotic pressure inside and outside to equal, so fluid doesn't move into the cell and cause it to burst.

Resource summary

	Created by Evian Chai almost 4 years ago