Chapter 8 Flashcards
Metabolism
Totality of organisms chemical reactions, consisting of anabolic and catabolic pathways
Metabolic pathways
Series of chemical reactions that either builds (anabolic) or breaks down (catabolic) molecules
Anabolic
Building complex molecules from simpler ones
Catabolic pathways
Breaking complex molecules to simpler ones
Chemical energy
Potential energy of a molecule in a chemical reaction
Open system
Can change and interact with there environment
Isolated systems
have no change on their surroundings
What are usable forms of energy partly converted to
Heat
First law of thermodynamics/ principle of conservation of energy
Energy can be transferred or transformed, but cannot be created
Entropy
Measure of molecular disorder, or randomness
2nd law of thermodynamics
Every energy transfer increase entropy of universe
Spontaneous process
A process that occurs without an overall input of energy; energetically favorable
Free energy
The portion of energy that can perform work when external factors are uniform
Factors affecting free energy
pH, concentration, temperature
When (delta)G is negative what process is most likely to occur
Spontaneous process
Exergonic reaction
Spontaneous chemical reactions in which there is a net release of free energy
Endergonic
Non spontaneous chemical reaction in which free energy is absorbed from their surroundings
ATP
Contains adenine, ribose sugar, and 3 phosphate groups.
T/F) ATP releases free energy when nucleosides are hydrolyzed.
True
Phosphorylated intermediate
Molecule with a phosphate group covalently bonded to it making it more reactive to un phosphorylated molecules
What provides free energy for phosphorylation of ATP
Exergonic breakdown (catabolism)
Activation energy
The amount of energy a reaction needs before a chemical reaction can begin
What energy can supply chemical reactions with activation energy
Thermal energy
Why can thermal energy supply reactions with energy for activation energy
Thermal energy makes the atoms faster
Transition state
When the molecules get enough energy they become unstable
Catalysis
Process of chemical agent increasing rate of reaction without being consumed
Substrate
The reactant that an enzymes works on
Enzyme-substrate complex
Temporary complex formed when an enzyme binds to its substrate
Active site
Region of enzyme’s that bind substrate and that forms the pocket in which catalysis occurs
Induced fit
Caused by entry of substrate; enzyme binds more snugly to substrate
What is used to hold induced fit
Weak interactions (hydrogen bonds, ionic bonds)
What makes the active sites of enzymes
R groups
How does enzymes lower activation energy
Stretching and contorting substrate making their bonds easier to break
When are enzymes saturated
When there is too many substrates in the solution
How to fix saturated enzymes
Add more enzymes
Cofactors
Nonprotein molecules or ions that is required for proper enzymatic activity
Coenzymes
Organic molecules serving as cofactor; most vitamins function as coenzymes
Competitive inhibitors
Substance that reduces the activity of an enzyme by entering active sites in place of the substrate
Which type of competitive inhibitors are irreversible
Covalently bonded inhibitors
Which competitive inhibitors are reversible
Weak interactions
What can be done to overcome competitive inhibitors
Add more enzymes
Non competitive inhibitors
Bind to another part of enzyme forcing the enzyme to change shape reducing catalysis ability
When does chemical chaos occur
When all cells metabolic pathways are operating simultaneously
Allosteric regulation
Binding of regulatory molecules to a protein at one site that affects the function of the protein at a different site
Allosteric enzymes
Made of 2 or more subunits, have the ability to switch to different forms; one active the other inactive
Can ATP bind to enzymes allosterically
Yes
What happens when ADP binds to an enzyme ATP inhibits
ADP Activates the enzyme
Cooperativity
Type of allosteric regulation where binding of a substrate causes a shape change in a subunit of a protein which is transmitted to other subunits
Feedback inhibition (metabolic)
Method of metabolic control in which the end product of a metabolic pathway inhibits an enzyme within that pathway
