Chapter Six: Energy, Enzymes, and Metabolism Flashcards
The total Chemical activity of a living organism
Metabolism
The type of energy possessed by moving objects
Kinetic Energy
The type of energy possessed because of location or arrangement
Potential Energy
This type of energy forms potential energy stored in molecules because of the arrangement of atoms
Chemical Energy
A series of Chemical Reactions
Metabolic Pathways
What are the two types of Metabolic Pathways?
Catabolic and Anabolic Reactions
Larger molecules are broken down into smaller ones with the release of potential chemical energy
Catabolic Reactions
Smaller molecules are built into larger ones with the input of potential chemical energy
Anabolic Reactions
First Law of Thermodynamics:
Energy may neither be created nor destroyed. However, it can be converted from one form to another
Second Law of Thermodynamics:
In any energy conversion, some energy is lost from doing work, so entropy increases
Total chemical energy of a molecule
Enthalpy (H)
The useable energy available for cellular work
Free Energy (G)
The unusable energy in a molecule
Entropy
What is the equation for Enthalpy (H)?
H = G + TS
Enthalpy = Free Energy + (Absolute Temp.)(Entropy)
In a chemical reaction, a molecule with one enthalpy is converted to another with…
a different enthalpy
The point in a reversible Chemical Reaction at which there is no net change in the concentration of reactants or products
Chemical Equalibrium
Difference in enthalpy between a reaction’s products and reactants
Gibbs Free Energy (∆G)
Reactants <—-> Products
Exergonic Reactions
Reactants + Energy <——> Products
Endergonic Reactions
Ke = Large # / Small # = value > 1
Exergonic reactions
Ke = small # / large # = value < 1
Endergonic Reaction
-∆G because products have less Enthalpy than the reactants, because energy was given off
Exergonic Reactants
+∆G because of energy input, products have more enthalpy than reactants
Endergonic Reactions
What energy source is used to transfer energy in cells?
ATP
ATP+ —> __________ + ____________
ADP + PO4-
What is the major function of ATP?
Couple Exergonic to Endergonic reactions
a substance that speeds up a chemical reaction without itself being used up
Enzymes (catalyst)
enzymes orient molecules to ___________ the reaction
facilitate
Small amount of energy which must be supplied before endergonic reactions will occur
Activation Energy
Site where substrate is bound and the reaction is catalyzed
Active Site
Occurs when a molecule is shaped very much like the substrate. It binds to and blocks the Active Site
Competitive Inhibitor
Occurs when an inhibitor binds to separate (Inhibition/Allosteric) Site, changing shape of the enzyme to an inactive conformation (shape)
Non-competitive Inhibitor
Those with more than one shape (conformation) depending upon whether a ligand (substrate, inhibitor, or activator) is bound
Allosteric Protein
Prosthetic groups are small molecules permanently attached to enzymes that aid in…
Catalysis
Cofactors are inorganic ions that bind to _____________ temporarily
Enzymes
Cofactors act as temporary electron….
acceptors or donors
Coenzymes are organic molecules that bind enzymes temporarily and __________ in the reaction
participate
Many coenzymes are derived from the _____________ necessary in our diet
Vitamins
What are the four denaturing agents?
- Heat
- Strong Acid
- Strong Base
- Highly Charged Ions
NAD+ is used to pick up electrons from an enzyme and store them temporarily before giving them to another enzyme
Coenzymes
A series of chemical reactions where the product at one reaction is the reactant for the next
Control of Metabolism
The slowest reaction, which limits the overall rate of the metabolic pathway, usually located at front of the pathway
Rate-limiting reaction
Occurs when product from end of a metabolic pathway acts as a noncompetitive inhibitor, inactivating an enzyme early in the pathway
Feedback Inhibition
Occurs when the shape of an enzyme is permanently altered, destroying its catalytic ability
Enzyme (Protein) Denaturation
