Metabolism
All the reactions taking place in an organism.
Anabolism
Anabolic rxn. Building up large molecules using dehydration rxn.
Catabolism
Catabolic rxn. Breaking down large molecules using hydraulic rxn.
First law of thermodynamics
Energy is neither created nor destroyed; instead, energy changes from one form to another.
Second law of thermodynamics
Systems are not efficient; energy is always lost to the surroundings, resulting in disorder (entropy), measured in temperature.
Homeostasis
The constant internal environment maintained by living things to fight against entropy.
Energy
The ability to do work.
Kinetic energy
Increase in kinetic energy leads to an increase in heat.
Potential energy
Stored energy located in bonds; stronger bonds have more energy.
Heat
The amount of collisions particles form with each other and surroundings.
Temperature
The average movement of particles.
ATP
Adenosine triphosphate, the most common chemical used in biology.
Coupling reactions
Pairing an exergonic reaction (supplies energy) with an endergonic reaction (allows it to occur).
Chemical work
Involves the synthesis, breakdown, and conversion of molecules.
Transport work
Involves the movement of substances across cellular membranes.
Mechanical work
Involves the physical movement or manipulation of cellular structures.
Enzymes
Proteins (sometimes RNA) that lower the activation energy (Ea) to speed up reactions.
Catalytic cycle of enzymes
Substrates enter the active site, forming an enzyme-substrate complex, and products are released.
Cofactors
Inorganic chemicals that help enzymes function.
Coenzymes
Organic chemicals that help enzymes function.
Factors that disrupt enzyme function
Pressure, temperature, pH, salt concentration, electricity, poison/inhibitors.
Active form of enzymes
Always function and must be turned off when not needed.
Inactive form of enzymes
Produced in a nonfunctioning form and must be turned on or activated.
Competitive inhibitors
Compete with the substrate for the active site.
Non-competitive inhibitors
Attach to the enzyme at another location (allosteric site) and change the shape of the active site.
Feedback regulation
Reactions are regulated by positive and negative feedback.
Positive feedback activation
As more products are created, enzymes work more and produce even more products.
Negative feedback inhibition
As products increase, the enzyme is inactivated.