-ATP (adenosine triphosphate) is the energy currency of the cell.

-Made of negatively charged phosphate groups attatched to an adenosine molecule. The phosphates repel, creating an unstable bond which is easily broken, releasing energy.

-Created by 3 mechanisms: 1) substrate phosphorylation 2) oxidative phosphorylation 3) photophosphorylation

1) Substrate Phosphorylation - Uses chemical energy to add phosphate ion to molecule of ADP

2) Oxidative Phosphorylation - Uses energy from proton motive force to add phosphate ion to ADP 

3) Photophosphorylation - Utilizes radiant energy from sun to convert phosphorylate ADP to ATP

-An energy source is a compound broken down to release energy. A variety of compounds are available, the most common being glucose.

-Harvesting energy requires a series of coupled reactions, such as the oxidative-reduction reactions

-The oxidative-reduction reactions occur when one or more electrons are transferred from one substrate to another.

(Compounds that LOSE electrons are oxidized[donor]; compounds that GAIN electrons are reduced[carrier]) 

-In reactions, electrons are removed, and protons generally follow them in the form of an H+ ion.

CARRIERS: NAD+ ; FAD ; NADP+ 

REDUCED FORMS(due to usable energy in bonds): NADH ; FADH(sub2) ; NADPH

-The 3 key central metabolic pathways are Glycolysis, Pentose phosphate pathway, and the Tricarboxcylic acid cycle.

-These pathways are catabolic and provide energy, reducing power, and precursor metabolites.

-The Pentose phosphate pathway is a process that serves to generate NADPH and the synthesis of pentose(5-carbon) sugars.

-There are two distinct phases in this pathway: 

1) The first is the oxidative phase, in which NADPH is generated. 

2) The second is the non-oxidative phase, which synthesizes the pentose(5-carbon) sugars. 

-This apthway is an alternative to glycolysis; it's primary role is anabolic rather than catabolic.

-Glycolysis is a 10 step process which ultimately converts one glucose into two pyruvate.

-The pathway generates 2 3-C pyruvate molecules 

-There is a net gain of two ATP (2 ATP are used to break glucose, 4 ATP are harvested) 

-Two molecules reducing power (NADH) 

-6 different precursor metabolites 

-ATP ultimatel produced by substrate-level phosphorylation

-The transition step is the step that links glycolysis to the Tricarboxylic Acid Cycle.

-It modifies the 3-C pyruvate from glycolysis to 2-C acetyl CoA(produced by removing CO2 thru decarboxylation, remaining 2-C acetyl group joined to coenzyme A) 

-Each pyruvate enters the transition step, and so the reaction occurs twice for one glucose.

-The transition step yields reducing power (NADH) and precursor metabolites (acetyl CoA)

-The Tricarboxylic Acid Cycle completes the oxidation of glucose.

-It incorportates acetyl CoA from the transition step, and releases CO2 in net reaction which generates NADH.

-The cycle turns once for each acetyl CoA, and twice for each glucose molecule. 

-The cycle produces 2 ATP, 6 NADH, 2 FADH2, and 2 precursor metabolites

-Coenzymes are organic cofactors which act as carriers for molecules or elections (NAD+, FAD+, and NADP+ are coenzymes)

-They are not as specific as enzymes, and may act with numerous enzymes.

-Enzymes function is a narrow range of environmental factors. Some factors which affect enzymatic activity are:

1) Temperature- Increased temperature increases the speed of the reaction, while extremely high temperatures makes enzymes non-functional.

2) pH - Enzymes function best at a pH just above 7 (neutral to slightly basic)

3) Salt concentration - Enzymes function best in lower concentrations of salt

-Enzyme activity can be controlled by allosteric regulation in two ways.

1) Allosteric inhibition - When enough of a product is made, a negative feedback signals the allosteric inhibitor the bind the the allosteric(non active site) area of the enzyme. This makes it so the active site becomes distorted, and the substrate cannot fit into the site, therefor ending the reaction. 

2) Allosteric activation - A signal (either feedback/feedforward) signals that more of a certain product needs to me made, so an allosteric activator is singaled to bind to the allosteric site of the enzyme, which makes the active site un-distorte, so the substrate can fit into it and more reactions can take place.

-In non-competitive inhibition, the inhibitor and the substrate at on different enzyme sites. An example of this is allosteric inhibition, where the inhibitor binds to a site other than the active site, which causes te active site to deactivate or distort.

-In competitive inhibition, an inhibitor which is sturcturally similar to the substrate competes with it for the active site, blocking the real substrate from binding to the enzyme.

Describe where ATP is made:

-ATP can be made in many ways:

1) Substrate phosphorylation(4 ATP)

a. 2 ATP from glycolysis 

b. 2 ATP from TCA 

2) Oxidative Phosphorylation(34 ATP) 

a. 6 ATP from glycolysis (from re-oxidation of 2 NADH)

b. 6 from Transition step (re-oxidation of NADH) 

c. 22 from TCA cycle (re-oxidation of NADH and FADH2) 

-In aerobic respiration, oxygen is used as the final electron carrier.

-In anaeroic respiration, oxygen is NOT used as the final electron carrier.

-The protein complexes are as follow:

1. Complex I 

2. Complex II 

3. Coenzyme Q 

4. Complex III 

5. Cytochrome C 

6. Complex IV 

-Complexes I, III, and IV are pumps

-Lipid catabolism can be integrated with carbohydrate metabolism because when they are hydrolyzed by lipase, the DHAP enteres glycolysis. Also ,fatty acids degraded by beta-oxidation form acetyl CoA which enters TCA cycle.

-Protein catabolism can be integrated with  carbohydrate metabolism because when they are hydrolyzed by proteases, the amino group is removed and the reaining carbon skeleton is converted to precursor metabolites.

-Lipid synthesis begins with transfer of acetyl group from acetyl CoA to acyl carrier protein. Glycerol is synthesized from DHAP

-Amino acid synthesishave precursors formed in glycolysis and TCA cycle. Precursors for aromatic amino acids are produced o nthe pentose phosphate pathway and glycolysis.

-Nucleotides are synthesized as ribonucleotides and modified to deoxyribonucleotides.