Chapter 2.3 Flashcards
Energy
The capacity to do work
Work
To move something
(Ex: Breaking chemical bonds, building molecules, pumping blood, contracting skeletal muscles, etc.)
Potential energy
Stored energy
Ex: water behind a dam
Kinetic energy
Energy of motion; energy that is doing work
Ex: Water flowing through a damn
Chemical energy
Potential energy stored in the bonds of molecules
Which type of energy is Heat Energy? What does it do to reactions?
The kinetic energy of molecular motion.
Temperature measures rate of motion.
> heat = >molecular motion
Electromagnetic energy
The kinetic energy of moving “packets“ of radiation called photons
Ex: light
Electrical energy
Potential energy of charged particles
AND
Kinetic energy of the charge particles moving and creating an electrical current
Free energy
Energy stored in the chemical bonds of organic molecules
Chemical reaction
Covalent or ionic bonds are formed or broken
Chemical equation
Reactants on the left, products on the right, with an arrow between.
Ex: ethanol + Oxygen —> acetic acid + water
Wine turning to vinegar if left out
Decomposition reactions
A large molecule breaks down into two or more small ones
Ex: 1 starch molecule into lots of glucose molecules, and then the glucoses to water and carbon dioxide molecules
Exchange reactions
Two molecules exchange atoms or groups of atoms AB + CD —> AC + BD
Ex: When stomach acid (HCl) enters the small intestine, the pancreas secretes sodium bicarbonate to neutralize it
NaHCO3 + HCl —> NaCl + H2CO3
Reversible reactions
Can go in either direction under different circumstances; Determined by the relative abundance of substances on each side of the equation
Law of mass action
Reversible reactions proceed from the reactants in greater quantity to the substances with the lesser quantity
Equilibrium
The ratio of products to reactants is stable
Reaction rate in concentration
Increase when the reactions are more concentrated; crowded molecules collide more frequently
Reaction rate and temperature
Reaction rate increases as the temperature rises; he causes rapid movement and more collision force and frequency
Reaction rates and catalysts
A kind of speeds up the reaction and can repeat it again
Ex: Enzymes
Metabolism
All of the chemical reactions in the body
Catabolism 
The sum of all decomposition reactions. Energy releasing
Break covalent bonds, produce smaller molecules from larger ones, and release energy used for work
Decomposition
Larger molecules broken down into smaller ones
Ex: Digestion and cell respiration
Endergonic reactions
require a net energy input, more total free energy
Oxidation:
Type of reaction and what it does
Exergonic reaction; molecule gives up electrons (H or H2) and releases energy —> product is oxidized
