Anatomy & Physiology Ch. 2 (Chemistry of Life)

Matter

Anything that has mass and occupies space

Atom

Smallest unit of matter

Protons

Found in Nucleus, positively charged

Electrons

Found outside Nucleus, negatively charged

Neutrons

Found in Nucleus, neutral charge

Atomic Number

Number of protons an atom has

Human body is made up of what 4 elements?

Hydrogen, Carbon, Oxygen, Nitrogen

Suspension

Mixture containing large, unevenly distributed particles

Colloid

Mixture with small, evenly distributed particles

Solution

Mixture with extremely small, evenly distributed particles

Molecule

Formed by chemical bonding between 2 or more atoms

Compound

Formed when 2 or more atoms of different elements combine by chemical bonding

Macromolecules

Very large molecules composed of many atoms

Molecular Formulas

Represent molecules symbolically with letters and numbers

Ionic Bond

Formed when electrons are transferred from a metal atom to a non metal atom. Results in the formation of ions

Anion

Negatively charged ion, formed when a nonmetal gains one or more electrons

Cation

Positively charged ion, formed when a metal loses one or more electrons

Covalent Bond

Strongest bond, formed when 2 or more nonmetals share electrons

Nonpolar Covalent Bond

When 2 nonmetals in a molecule with similar or identical electronegativities pull with equal force and share electrons equally

Polar Covalent Bonds

When nonmetals with different electronegativities interact resulting in unequal sharing of electrons

Hydrogen Bonds

Weak attraction between a partially positive end of one dipole and a partially negative end of another dipole.

Dipole

Polar molecules with partially positive and partially negative ends

Energy

The capacity to do work, put matter into motion and/or fuel chemical reactions

Potential Energy

Stored energy that can be released to do work at a later time

Kinetic Energy

Potential energy that has been released or set in motion to perform work

Chemical Energy

Energy found in bonds between atoms, drives nearly all chemical processes

Electrical Energy

Energy generated by movement of charged particles or ions

Mechanical Energy

Energy directly transferred from one object to another

Endergonic Reaction

A reaction that requires input of energy from another source. Products have more energy than reactants

Exergonic Reaction

A reaction that releases extra energy so the products have less energy than the reactants

Catabolic (decomposition) Reaction

A reaction where a substance is broken down into smaller substances

Ex: AB -> A+B

Exchange Reaction

A reaction where one or more atoms from reactants are exchanged for one another

Ex: AB+CD -> AD+BC

Anabolic (synthesis) Reaction

A reaction that occurs when small, simple subunits are united by chemical bonds to make large, more complex substances

Ex: A+B -> AB

Oxidation-Reduction Reaction

A special kind of exchange reaction, occurs when electrons and energy are exchanged instead of atoms

Activation Energy

The energy required for all chemical reactions

Catalyst

A substance that increases reaction rate by lowering activation energy required without being consumed or altered

Enzyme

A biological catalyst (typically a protein)

Biochemistry

The chemistry of life and living things

Inorganic Compounds

A compound that does not contain Carbon

Organic Compound

A compound that contains Carbon bonded to Hydrogen

Key Properties of Water

High heat capacity, able to evaporate, cushions & lubricates

Acid

Hydrogen ion or proton donor, low numbers on pH scale

Base (alkaline)

Hydrogen ion acceptor, higher numbers on pH scale

pH scale

A representation of the hydrogen ion concentration in a substance

Buffer

A chemical system that resists changes in pH, prevents large swings in pH when an acid or base is added to a solution

Salt

Any metal cation and nonmetal anion held together by ionic bonds

Monomer

Single subunits that can be combined to build polymers by dehydration synthesis

Hydrolosis

A catabolic reaction that uses water to break up polymers into smaller subunits

Carbohydrates

Composed of carbon, hydrogen & oxygen and function as fuel

Monosaccharides

Consist of 3 to 7 carbons. They are monomers from which all carbohydrates are made

Ex: Glucose, fructose, ribose & dioxyribose

Disaccharides

Formed by the union of 2 monosaccharides by dehydration synthesis

Polysaccharides

Consist of many monosaccharides joined to one another by dehydration synthesis

Lipid

A group of nonpolar hydrophobic molecules composed primarily of carbon and hydrogen

Fatty Acids

Lipid monomers consisting of 4 to 20 carbon atoms

Saturated Fatty Acids

Solid at room temperature, have no double bonds between carbon atoms so carbons are "saturated" with maximum number of hydrogen atoms

Monosaturated Fatty Acids

Generally liquid at room temperature, have one double bond between two carbon atoms in a hydrocarbon chain

Polyunsaturated Fatty Acids

Liquid at room temperature, have 2 or more double bonds between carbons in a hydrocarbon chain

Triglyceride

3 fatty acids linked by dehydration synthesis to a modified 3-carbon carbohydrate

Proteins

Macromolecules that function as enzymes, play structural roles, are involved in movement & can be used as fuel

Peptides

Formed from 2 or more amino acids linked together by peptide bonds through dehydration synthesis

Dipeptides

Consist of 2 amino acids

Tripeptides

Consist of 3 amino acids

Polypeptides

Consist of 10 or more amino acids

Fibrous Protein

Long, rope-like strands, composed mostly of nonpolar amino acids, link things together and add strength and durability to structures

Globular Protein

Spherical or globe-shaped, composed mostly of polar amino acids, function as enzymes, hormones & other cell messengers

Protein Denaturation

Process of destroying a protein's shape by heat, pH changes, or exposure to chemicals

Nucleotides

Monomers of nucleic acids, named because of abundance of nuclei of cells, make up genetic material

Neucleotide structure

Nitrogenous base with a hydrocarbon ring structure, 5-carbon pentose sugar, ribose, or deoxyribose & a phosphate group

Purines

Double-ringed molecule; Adenine & Guanine

Pyrimidines

Single-ringed molecule; Cytosine, Uracil & Thymine

Adenosine Tri-Phosphate (ATP)

Adenine attached to ribose and 3 phosphate groups; Main source of chemical energy in the body; Requires oxygen

DNA

An extremely large molecule found in the nuclei of cells, composed of 2 long chains that twist around each other in a double helix. Contains genes which provide codes for protein synthesis

DNA Base Pairs

Adenine + Thymine (double bond)

Cytosine + Guanine (triple bond)

RNA

Single strand of nucleotides, can mve between nucleus of cell and cytosol; Critical to making proteins

Uracil

RNA's replacement for Thymine