Part 3: Cellular Energetics Flashcards
Enzymes
Biological catalysts; enable cells to break chemical bonds without using (much) energy; speed up reaction without changing it by lowering the reaction’s activation energy
Bioenergetics
The study of how cells carry out the processes necessary for life, and the way in which cells release energy when they need it and store it when they don’t; how energy from the sun is transformed into energy in living things
Exergonic reactions
Products have less energy than reactions, energy is given off during reaction
Endergonic reactions
Reactions that require an input of energy; products have more energy than reactants
Activation energy
Energy required to start a reaction and break the chemical bonds of the reactants; energy barrier
Enzyme specificity
Property of enzymes that they can only catalyze one type of reaction; each enzyme can only bind to one specific substrate
Substrate
Targeted molecules in an enzymatic reaction
Active site
Place on the enzyme that a substrate binds to
Enzyme-substrate complex
Molecule formed by the binding of a substrate onto an enzyme
Induced fit
Enzyme slightly changes shape to accommodate substrate
Coenzymes
Organic factors that aid an enzyme in catalyzing a reaction; accept electrons and pass them on to another substrate; ex. Vitamins
Cofactors
Inorganic molecules that help catalyze reactions; usually metal ions (Fe+2)
Allosteric sites
Sites other than the active site that other substances can bind to
Allosteric regulators
The “other substances” that can bind to the allosteric site to inhibit or activate enzymes
Allosteric inhibitor
Allosteric regulator that inactivates the enzyme
Allosteric activator
Allosteric regulator that induces an enzymes function
Feedback inhibition
Formation of an end product inhibits an earlier reaction in the sequence
Competitive inhibition
A substance that has the shape that fits the active site of an enzyme blocks the substrate from binding to the active site and inactivates enzyme
Noncompetitive inhibition
Inhibitor binds with enzyme at a place other than the active site and inactivates enzyme by changing its shape
First law of thermodynamics
Energy cannot be created or destroyed
Second law of thermodynamics
Energy transfer leads to less organization; universe tends toward chaos (entropy)
Entropy
Chaos, disorder
Photosynthesis
Transformation of solar energy into chemical energy
6CO2 + 6H2O + sunlight –> C6H12O6 + 6O2
Cellular respiration
C6H12O6 + 6O2 –> 6CO2 + 6H2O + ATP
Way to synthesize ATP
Aerobic or anaerobic