Chapter 8 Flashcards
Catabolic rxns
Breakdown complex molecules and real ease energy
Anabolic rxns
Use energy to build complex molecules
Capacity to cause change
Energy
Associated w/random mvmts of molecules
Heat-kinetic energy
Available for release in a chemical rxn
Chemical-potential energy
Study of energy transformations that occur in a collection of matter
Thermodynamics
1st law of thermodynamics
Energy can be transferred/transformed but not destroyed
2nd law of thermodynamics
Every energy transformation or transfer increases the entropy of the universe
Measure of disorder/randomness
Entropy
Cells do 3 types of work:
- chemical (building polymers)
- transport (pumping molecules across membrane)
- mechanical (muscle contraction)
Use of exergonic rxns to drive endergonic rxns
Energy coupling
Breaking a bond
Releasing energy
Exergonic rxn
Requires energy
Endergonic
Proteins (mostly) which act as catalysts and speed up rxns
Enzymes
Act by lowering/raising the activation energy?
Lowering
True or false: can make endergonic rxn exergonic
FALSE
Reactant acted on by the enzyme
Subtrate
Region that actually binds the substrate
Active site
Binding of substrate causes the enzyme to slightly change shape
Induced fit
Nonprotein helpers
Cofactors
Resemble subtrate sand compete for active site
Competitive
Bind to enzyme somewhere other than active site and cause a conformational change which decrease activity
Noncompetitive
Binding of regulatory molecule at one site affects the activity at a separate site
Allosteric regulation
- end prod of a pathway can bind to an enzyme that acts earlier in the pathway and inhibit it
- prevent cells from wasting energy to make xs product
Feedback inhibition
Enzymes can be compartmentalized or assembled into multienzyme complexes
Localization of enzymes
