Metabolic Pathways & Cellular Respiration
Metabolic Pathway
begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product
Catabolic Pathway
Anabolic Pathway
Breakdown pathway
Metabolic Pathway releases energy by breaking down complex molecules into simpler ones
consumes energy to build complicated molecules from simpler ones
Forms of Energy
energy
is the capacity to cause change
Kinetic Energy
energy that can be associated with the relative motion of objects
Thermal Energy
is kinetic energy associated with the random movements of atoms or molecules
Potential Energy
an object not possessively moving but still possesses energy
Chemical Energy
is energy stores in the bonds of chemical compounds
Laws of Thermodynamics
Thermodynamics
the study of the energy transformation that occur in a collection of matter
First Law
energy can be transferred and transformed, but it cannot be created or destroyed
the principle of conservation of energy
2nd Law
every energy transfer or transformation increases the entropy of the universe
Entropy
the measure of molecular disorder or randomness
Spontaneous Process
an increase in entropy and process can proceed without requiring an input of energy
Free Energy
is the portion of a systems energy that can perform work when temperature and pressure are uniform throughout the system
Its tendency is to change to a more stable state
Unstable systems tend to have a higher G and tend to change to become more stable and have a lower G
Exergonic Reaction
proceeds with a net energy of free energy
G is negative
spontaneous reaction
it is energetically favorable
endergonic reaction
is one that absorbs free energy from its surroundings
G is postive
nonspontaenous reaction
Energy Coupling
the use of an exergonic process to drive an endergonic process
ATP is responsible for mediating most energy coupling in cells
The bonds between the phosphate group of ATP can be broken down by hydrolysis
release of free energy
ADP + Phosphate group goes to ATP + H2O
catabolic pathways provide the energy for the endergonic process of making ATP
Enzymes
macromolecule tjat acts as a catalyst, a chemical agent that speeds up a reaction without being consumed by the reaction
Catalysis
a process by which a catalyst selectively speeds up a reaction without itself being consumed
an enzyme catayses a reaction by lowering the activation energy barrier enabling the reactants molecules to absorb energy
substrate
the reactant an enzyme acts on
the enzyme binds to the substrate forming an enzyme substarte complex
active site
typiclly a pocket or groove on the surface of the enzyme where catalysis occur
Temperature and Ph can effect conditions on enzyme activity
Competitive Inhibitors
reduce the productivity of enzymes by blocking the substrates from entering the active sites
noncompetitive inhibitors
do not directly compete with the substrate to bind to the enzyme at the active site
Aerobic Cellular Respiration
Glycolysis
Citric Acid Cycle or Krebs Cycle
Electron Transport Chain
Transition Reaction
occurs in the cytosol, begins the degradation by breaking down glucose into two molecules of a compound called pyruvate
the breakdown of glucose to carbon dioxide is completed
aaccepts electrons from NADH or FADH2 generating during the first two stages and passes these electrons down the chain
Reactants
1 glucose, 2 NAD+, and 2 ADP+2P
Products
2 ATP, 2 Pyruvic acid, 2 NADH, 2H
Happens in the mitochondrial matrix'
Reactants
2 Acetyl COA, 6 NAD, 2 ADP+2P, 2 FAD
Producrs
4 CO2, 6 NADH, 2 FADH2, 2 ATP
occurs in the inter-membrane of the mitochondria
Reactants
10 NADH, 2 FADH2, O2, H, ADP, P
Products
H2O, 32 or 34 ATP, NAD, FAD
Reactants
2 Pyruvic Acid, 2 NAD, 2 Coenzyme A
Products
2 CO2, 2 NADH, 2 Acetyl Coa
converts two molecules of 3 carbon pyruvate from glycolysis into two molecules of the 2 carbon molecule acetyl conenzyme A and 2 molecules of carbon dioxide
It takes place in the matrix of the mitochondria
Anaerobic Cellular Respiration
a type of respiration where oxygen is not used; instead organic or inorganic molecules are used as final electron acceptors
Alcohol Fermentation
when pyruvate is converted into ethanol
Release of CO2 from the pyruvate which is converted to the two carbon compound acetaldehyde then acetaldehyde is reduced by NADH to ethanol
Lactic Acid Fermentation
pyruvate is reduced directly by the NADH to form lactate at an end product, regenerating NAD with no release of CO2