2.B.1

·      Discuss how cell membranes separate the internal environment of the cell from the external environment of the cell. Cell membranes separate the internal environment of the cell from the external environment of the cell by selective permeability being a direct consequence of membrane structure.

·      Cells are selectively permeable. Discuss each point below and how it allows the cell to be selectively permeable.

o   Discuss the following structures and the role the play in the cell membrane: phospholipids, embedded proteins, cholesterol, glycoproteins and glycolipids phospholipids give the membrane both hydrophilic and hydrophobic properties. Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups. Cholesterol help maintain the cells membranes fluidity. Glycoproteins are membrane protein with bound. Glycolipids serve as markers from cell to cell membrane.

o   Discuss the properties of a phospholipid (hydrophobic/phallic, polar/non, and fatty acids/phosphates. The hydrophilic phosphate portions of the phospholipids are oriented toward the aqueous external or internal environments, while the hydrophobic fatty acid portions face each other with the interior of the membrane itself.

o   Embedded proteins – how do they allow transport? Embedded proteins transport through active transport. Active transport is when proteins embedded in the cell's lipid bilayer. Those proteins do much of the work in active transport. They are positioned to cross the membrane so one part is on the inside of the cell and one part is on the outside. Only when they cross the bilayer are they able to move molecules and ions in and out of the cell.

o   Discuss which molecules can easily pass through the membrane and which can’t. Why? Water and oxygens and smaller molecules can go through.

·      Cell walls are a structural boundary that provides extra barrier for some organisms.

o   Discuss the cell wall of plant cells, prokaryotes and fungi, and what they are composed of. Plant cell walls, prokaryotes and fungi are made up of cellulose.

2.B.2

·      Passive transport does not require the input of energy; the net movement of molecules is from high to low. Discuss the following factors relating to passive transport.

o   Discuss how primary transport allows for export of waste. Primary transport allows for the export of waste by the movement of molecule down the concentration gradient. From an area of high concentration to low concentration.

o   Discuss how membrane proteins play a role in facilitated diffusion of charged/polar molecules in the membrane. Use the examples of glucose and Na/K transport. Membrane proteins play a role in facilitated diffusion of charged and polar molecules through a membrane example of this are glucose transport and na+/K+ transport.

o   Discuss the following solutions and their effect on a cell. Hypotonic, hypertonic, and isotonic. Hypotonic solutions have a higher water concentration and lower solute concentration. Hypertonic solutions have a lower water concentration and a higher solute concentration isotonic solution is equal for both.

o   Discuss water potential and the formula for solving for it. Water potential is just potential energy of water relative to pure water. The formula for solving is just solute potential plus the pressure potential.

·      Active transport requires free energy to move molecules against their concentration gradient from areas of low to high. Discuss the following factors relating to active transport:

o   Discuss where the free energy used in active transport comes from.

o   Discuss the membrane proteins needed for active transport.

o   Explain how molecules are moved against their concentration gradient. Use the example of the Sodium Potassium Pump. 

o   Discuss the difference between endocytosis and exocytosis.

§  What happens in each? Endocytosis in inside and exocytosis is outside of the cells what occurs is in endocytosis is the cellular uptake of biological molecules and particulate matter via formation of new vesicles from the plasma membrane. Exocytosis is the cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane.  

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o   Discuss the difference between pinocytosis and phagocytosis. Pinocytosis is the drinking and phagocytosis is the eating inside the cell membrane.

2.B.3

·      Discuss how internal membranes facilitated cell process by minimizing competing interactions by describing the activities of the lysosome.

·      Membranes and membrane bound organelles in eukaryotic cells processes. Discuss each of the following and how they compartmentalize: ER, mitochondria, chloroplast, Golgi, and nuclear envelope.

·      Discuss how prokaryotic cells function since they have no membrane bound organelles.