Blog 5: 20 Points on p.58-77

Metabolism

Laws of Thermodynamics
1) The total amount of energy in the universe is constant. Energy is neither created nor destroyed but converted from one form to another. A gain in energy in an object or process means a loss of energy elsewhere in the universe.
2) The entropy of the universe increases with any change that occurs. Things become more random and disorganized.

-Catabolic reaction; reaction that breakdown complex substances

-Anabolic reaction; reaction that builds complex substances from simpler subunits

-Collectively, the sum of all anabolic and catabolic processes in a cell or organism is called metabolism

-Energy is absorbed when reactant bonds break and energy us released when product bonds form

-Activation energy is the amount of energy needed to strain and break the reactants' bond

-Entropy; a measure of the randomness or disorder in energy or in a collection of objects

-Free energy; energy that can do useful work

-Organisms have cells that go through anabolic processes that seems to violate the second law of thermodynamics by apparently causing the universe to become a little more ordered

-Order by anabolic processes is overshadowed by greater disorder from catabolic processes.

-Living organisms build up their bodies and the world around them at the expense of the entropy of the universe as a whole

-Exergonic reaction; spontaneous with a decrease in free energy

-Endergonic reaction; not spontaneous with an increase in free energy

-Adenosine triphosphate (ATP) is the primary source of free energy in living cells. When a phosphate is broken from the chain, free energy is released

-Phosphorylation is the process of attaching a phosphate group to an organic molecule such as ADP which causes the molecule to become more reactive

Enzymes

-Enzymes are protein catalysts that speeds up a chemical reaction without being consumed in the processed

-Competitive inhibitors can block a normal substrate from binding to an enzyme's active site

-Noncompetitive inhibitors alter the enzyme's shape so it loses it's affinity for its substrate

-Allosteric sites on the enzymes can have substances bind to it that affect the active sites of the enzyme

-Feedback inhibition is a method of metabolic control in which a product formed later in a sequence of reactions allosterically inhibits an enzyme that catalyzes a reaction occurring earlier in the process