Campbell Biology, Chapter 8 Flashcards
What is the Metabolism
The totality of an organism’s chemical reactions
What are Catabolic Pathways
Metabolic Pathways that release energy by breaking down complex molecules to simpler molecules
What is a metabolic pathway
a specific molecule is altered in a series of defined steps, resulting in a certain product.
What are Anabolic Pathways
consume energy to build complicated molecules from simpler ones
What is Energy
energy is the ability
to rearrange a collection of matter
What is Kinetic Energy
relative motion of objects
What is Thermal Energy
kinetic energy associated with the random movement of atoms or molecules
What is Potential Energy
energy that matter possesses because of its location or structure.
What is the First Law of Thermodynamics
Energy can be transferred
and transformed, but it cannot be created or destroyed
What is Thermodynamics
study of the energy transformations that occur in a collection of matter
What is Entropy
measure of molecular disorder, or randomness
What is the Second Law of thermodynamics
Every energy transfer or transformation increases the entropy of
the universe.
What are Spontaneous Processes
if a given process, by itself, leads to
an increase in entropy, that process can proceed without
requiring an input of energy
What is Free Energy
portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system,
What are the 2 classifications of a chemical reaction
exergonic or endergonic
What is an Exergonic Chemical Reaction
energy outward
What is Endergonic chemical reaction
energy inward
What is energy coupling
the use of an
exergonic process to drive an endergonic one
How is energy made with ATP
Hydrolysis reaction in phosphate groups lead to products of ADP and inorganic Phosphate
What do enzymes do
Lower activation energy for a reaction to occur
What are chemical reactions in a simple explanation
breaking and forming of bonds
What is needed for a reaction to occur
reactant molecules must absorb energy to reach a high-energy, unstable state
What happens after a reaction
Once the reaction proceeds and new bonds form, energy is released, and the molecules return to a more stable, lower-energy state.
Role of Heat on chemical bonds
Heat increases the kinetic energy of molecules, leading to more frequent and forceful collisions, making it easier for bonds to break.
Are Complex Molecules stable or unstable
Complex molecules like proteins and DNA are inherently unstable and tend to break down spontaneously.
What is a substrate
The specific substance on which an enzyme acts.
Enzymes usually end in
-ase
Why do enzymes only bind to specific substrates
The 3 dimensional active site of an enzyme is a region with a specific shape and chemical properties that complements the shape and chemical properties of its substrate.
Can enzymes change shape
Yes
What is Induced fit in an enzyme
tightening of the binding after initial contact
How do enzymes bind to their substrates
weak interactions like hydrogen bonds and ionic bonds.
What catalyzes the conversion of substrate to product in an enzyme
The amino acid side chains within the active site catalyze the conversion of the substrate into product(s).
Are most enzyme-catalyzed reactions reversible
Yes
How does an enzyme become saturated
When all active sites are in use
Relation between temperature and enzymes
Enzymes have a specific temperature where they work the best and higher temperatures lead to more collisions among enzymes and substrates, increasing the amount of reactions catalyzed
What are cofactors in enzymes
Non-protein molecules that assist enzymes in their catalytic activity
What are Coenzymes in Enzymes
Organic molecules that act as cofactors. Many vitamins are essential for coenzyme synthesis.
What is enzyme inhabition
molecule binds to an enzyme and reduces its activity
What are the 2 main ways enzyme inhibition can occur
Reversable and Irreversible
2 Ways reversable enzyme inhibition can occur
Competitive and Noncompetitive Inhibition
What is Competitive inhibition
The inhibitor competes with the substrate for the active site. I
What is Noncompetitive inhibition
The inhibitor binds to a site other than the active site, changing the enzyme’s shape and reducing its activity.
How does irreversible inhibition occur
The inhibitor binds tightly to the enzyme, often forming a covalent bond, permanently inactivating it.
What is Allosteric regulation
mechanism by which the activity of an enzyme is controlled by the binding of a regulatory molecule to a site other than the active site.
What is Feedback Inhibition
ensures efficient resource allocation and prevents overproduction of metabolic products
