Movement Across CM

Movement Across CM

Cell Membrane

Various ways in which cells take in/out particles

particles meaning gases, ions, compounds and molecules

Movement Across Cell Membrane

Fundamentals:

• The cell membrane is a semipermeable membrane = cellular border
  • This property defines what can come and go through the cellular border
    • What price is necessary for molecules to cross the cellular border

Types of Movement:

• Simple Diffusion = PASSIVE
  • [Higher] to a region of a [lower]

Osmosis is the simple diffusion of water from a [lower solute] to [higher solute] Impermeable to a particular solute

• Facilitated Diffusion = PASSIVE

Down concentration gradient with help of carrier molecules Concept Link

• Active Transport = ACTIVE

against [gradient] w/ transport proteins

Concepts:

• The physics explains the NET MOVEMENT of particles
• Conservation of Matter & Energy (footnote)
• The chemistry of the cell membrane will explain the DRIVING FORCE CONDITIONS behind the physics
• Concentration Gradients - CHM 
• The biology explains the FUNCTIONAL STRUCTURES that use the chemistry
• Biomolecules - and their properties pertaining to gaining entrance through
• Intercellular Connections
• Tonicity 
• Mechanism of Small Molecules Traversing Lipid Bilayer
• Permeability of small molecules is correlated with their relative solubilities in water and nonpolar solvents
  • Molecule sheds water it is solvated in (solvation shell)
  • Disolves in the hydrocarbon core
  • Diffuses through this core to the other side of the membrane
  • Molecule is resolvated
    • Meaning that to shed the solvated molecule may become unfavorable and therefore cannot pass through the lipid bilayer

Building Concepts:

• Action Potential

Links:

Footnote: Warning Nerd Talk Disclaimer Warning
Conservation of Mass and Energy as a Physical concept first before Chemistry

• Yeah its used in chemistry too but it came from the ideas of physics
• Long story short ancient Greeks started coming up first with physical concepts which then evolved into chemical concepts
• So what if they were making metals for weapons way earlier, its not really conceptual but more trial and error OR cooking with metals; it was not an conceptual science until the father of science thought up of some basic concepts, damn im rambling. grr
• Chances are in terms of sciences it is not the "chicken or the egg" paradox over Physics, Chemistry and Biology: Physics will always be the foundation onto which all other branches of science will start, seriously: its the humble older brother. Biology is the flashy younger brother, they are like "Yo, swag, check out my new fancy DNA concepts and molecular biology. Ive got so many nobel awards lately and they are talking about my paradigm shifts. I got them all wet with my Western Blott, taking care of an AIDS epidemic, you know, making the world a better place; better than Captain Planet. So Physics, why dont you drop another apple or something cuz youre slacking: playing with silly string and how many dimensions are you at now? You need to lay off of Chemistry's ether, seriously. Id like to party with you guys but I cant keep these groupies off me with a pipette. And im just super busy trying to cure cancer and all." While everyone's like "what evs Biology, what evs." Chemistry? I'm not even gonna talk about Chemistry. They are just over there playing with water and dissolving things, jeez. I mean its just another crazy day in the science household... 
• Wait, where was I? What evs.