An introduction to metabolism, cellular respiration and fermentation.
Metabolism: the totality of an organism's chemical reaction.
Arranged in " metabolic path ways " which begin with a specific molecule and transformed to a specific product, each catalyzed by a specific enzyme.
Anabolic pathway: consume energy to build complicated molecules from simple ones.
Catabolic path way: release energy by breaking down complex molecules to simpler compounds.
Forms of Energy
Energy: is the capacity to cause change.
Thermal energy: is kinetic energy associated with random movement of atoms and molecules.
Potential energy: matter possesses because of its location or structure.
Kinetic energy: associated with the relative motion of an object.
Chemical energy: term used to refer to potential energy available for release in chemical reaction.
The Laws of Energy
Thermodynamics, is the study of energy transformation that occurs in a collection of matter.
The 1st law of thermodynamics: Stablishes energy can be transferred or transformed but neither created nor destroyed .
The 2nd law of thermodynamics:Every energy transfer or transformation increases the disorder entropy (molecule disorder) of the universe.
The Free Energy Change of a Reaction
Free energy, is the portion of a system's energy that can perform work when temperature and pressure are uniform in the system.
Free energy and metabolism, we can use free energy concept for the chemistry of life's process.
Endergonic reaction: is one that absorbs free energy from its surroundings.(energy inward)
Exergonic reaction: process with a net release of energy. (energy outward)
ATP Cellular Work by Exergonic or Endergonic reaction.
Energy coupling: is the use of exergonic process to drive an endergonic one.
ATP(adenosine triphosphate) in adiition to its energy coupling ATP is one of the nucleoside triphosphate used to make RNA.
ATP and how its hydrolysis performs, once atp is hydrolyzed the release of free energy merely heats the surrounding water.
Enzymes and Metabolic Reactions
An enzyme, is a macromolecule that acts as a catalyst a chemical agent that speeds up a reaction.
The reactant an enzyme acts on as the enzyme's substrate.
enzyme-substrate complex, when enzyme binds to its subtrate
Cofactors,non protein helpers fpor catalytic activity.
Cofactors: adjuncts bound tightly to the enzyme as permanent residents or may loosely along the substrate.
Coenzymes: if the cofactor is an organic molecule
Enzymes inhibitors.
Competitive inhibitors: reduce the productivity of enzymes by blocking substrates from entering the active site.
Noncompetitive inhibitors: do not directly compete with the substrate to bind the enzymes at the active site.
Catabolic Pathway and ATP Production.
catabolic process, fermentation is a partial degradation of sugars or other organic fuel that occurs without the use of oxygen.
The most effective catabolic pathway will be " aerobic respiration" in which oxygen is consumed as a reactant along with the organic fuel.
Redox Reactions: Oxidation and Reduction
Oxidation: the loss of electrons from one substrate in the a redox reaction.
Reduction: the addition of electrons to another substrate.
Redox reactions:chemical reactions there is a transferred of one or more electrons from one reactant to another.
Stepwise Energy Harvest
coenzyme well suited as an electron carrier because it can cycle easily between its oxidation form NAD+ and its reduce form NADH.
The Stages of Cellular Respiration
Pyruvate Oxidation and Citric Acid Cycle
Oxidation Phophyralation
Glycolysis.
Takes place in the cytosol, begins the degradation process by breaking glucose into two molecules of compound called pyruvate.
After the pyruvate enters the mitochondria and is oxidized to a compound called acetyl CoA , enters the Citric cycle: here the breakdown of glucose to carbon is completed. As well as redox reaction takes place here where in which dehydrogenases ransfer electrons from substrates to NAD+ or FAD forming (FADH and NADH).
The electron transport chain accepts the electrons NADH or FADH , which are combined with molecular oxygen and hydrogen ions, forming water in a for that mitochondrion use to make TP from ADP.