Biology Chapter 2
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Biology Chapter 2
What are the two types of energy?
Potential Energy - stored energy; available to do work.
Kinetic Energy - energy of motion.
(Potential energy can be converted to kinetic)
What is the first law of Thermodynamics?
Energy is never created or destroyed!
What are five forms of energy?
Mechanical - energy of movement
Nuclear - energy from reactions involving atomic nuclei.
Electrical - flow of charged particles.
Radiant - energy in heat, light, x-rays, & microwaves.
Chemical - energy in chemical bonds.
What is an atom?
The smalled units of matter that can exist separately.
The Periodic Table
Atoms are composed of:
Protons - Positive
Neutrons - no charge
Electrons - Negative (always in motion; moves in a strategic way)
Atomic # - #of protons = # of neutrons.
Pos + Neg = Neutral.
They exchange/steal electrons.
ex. Sodium & Chloride; Sodium gives an electron to Chloride.
The sharing of electrons instead of exhanging them.
How many electrons does each ion have Na+ & C1-
Na+ = 10
(Positive subtract one, negative add one)
What makes water polar?
The electrons are more around the oxygen so they are not shared equally between hydrogen and oxygen.
What is a hyrdogen bond?
The postitive hydrogen end of one polar molecule is attracted to the negative end of another polar molecule.
Reactants - substances that are changed; usually on the left side.
Products - new chmecial substances formed, usually on the right side.
Five important Chemical Reactions
What are Oxiation-Reduction Reactions?
Reactions in which electrons are transferred from one atom to another.
Oxidation - an atom loses an electron.
Reduction - an atom gains an electron.
ex. Respiration (Sugar is oxidized to form carbon dioxide and oxygen is reduced to form water)
What are Dehydration Synthesis Reactions?
When two small molecules are joined to form a larger molecule (s molecule of water is released)
ex. joining amino acids to form proteins.
What are Hydrolysis Reactions?
When a larger molecule is broken down into smaller parts (opposite of dehydration synthesis)
ex. digesting proteins into amino acids.
What are Phosphorykation Reactions?
When phosphate groups are added to other molecules,
phosphate groups are clusters of oxygen and phosphate atoms.
ex. Q-P + Z turns into Q + Z-P
What are acid base reactions?
pccurs when ions from an acid interact with ions from a base.
ex. H+Cl- + Na+OH- = Na+Cl- + H+OH-
Hydro. Acid + Sodium Hydroxide = Salt Water
neither acids nor bases.
What is the definition of pH?
phH is the measure of hydrogen concentration.
(pH of one has the highest lvl of hydro. concentration.)
What product is always given off in a dehydration synthesis reaction?
A molecule of water is released.