Membranes and Energy

"Hurry up Billy Bob"

Membranes - Act as barriers and made of a double layer of lipids with proteins embedded in them.

          Selectively permeable - let some things through and keep others out.

Channel proteins - Nonselective transport - Proteins with channels through them.

Solution - Liquid with something dissolved in it.

          Solvent - Liquid

          Solute - substance dissolved in the fluid.

Diffusion - molecules flow from a high concentration to a lower concentration.

Osmosis - only when water is moving through a membrane from a high concentration to a lower concentration.

Isotonic - a fluid that has the same number of solutes as the fluid inside the cell.

Carrier proteins - Selective transport - Moves a specific ion across a membrane.

          Facilitated diffusion - Moves a specific ion across a membrane from high to low concentration.

          Active transport - Moves a specific ion across a membrane from low to high concentration (needs energy.)

                    Chemiosmosis - added energy moves H+ across a membrane from low to high concentration then as they come back across they form ATP.

Energy - The capacity to do work.

          Exergonic reactions - will occur on their own without having to add energy.

          Endergonic reactions - require energy to occur.

ATP - (Adenosine Triphosphate) - The immediate source of energy that drives most cellular work.

          Adenine (a nucleotide)

          Ribose (5 C Sugar)

          3 Phosphate groups (stored energy)

ADP - (Adenosine Diphosphate) - Missing 1 phosphate.

Enzymes - speed up and control reaction rates.

          Activation Energy - The energy needed for the molecules to react

          Active site - region on the enzyme which binds to the substrate

          Substrate - The substance being acted upon (A + B or C)



Reactant + Reactant = Product

       A     +       B       =     C



ATP ---> ADP + P +   ( Release 7.3 kcal energy )

Glutamic acid + Ammonia + 3.4 kcal energy = Glutamine



ADP + P + ( Need 7.3 kcal energy ) ---> ATP



Enzyme + Substrate = Product + Enzyme






































Return to Greg Sievert's GB 100 Syllabus
Last updated on 4 January 2018