Topic 2 Flashcards
Atomic number
Number of protons in an atom
Mass number
Sum of protons and neutrons in an atom
Atomic mass
The average mass of all naturally occurring isotopes
Ions
Atoms that have given up or gained an electron in their outer electron shell
Molecules
Formed when atoms share electrons
Ionic bonds
Form when an atom loses or gains a valence electron
Covalent bond
Atoms share electrons rather than gain/lose them
Single covalent
2 atoms share 1 electron pair
Double covalent
2 atoms share 2 pairs of electrons
Triple covalent
2 atoms share 3 electron pairs
Nonpolar covalent
Electrons are shared equally
Polar covalent
Unequal sharing of electrons
Hydrogen bonds
Polar covalent bonds that form between hydrogen atoms and other atoms
Chemical bonds (what do they do)
Forces that hold the atoms of a molecule together
3 types of chemical bonds
Ionic, covalent, hydrogen
Chemical reactions
Occur when electrons in valence shell are shared/transferred. New bonds form and/or old bonds are broken
Exergonic reaction
Releases energy
Endergonic reaction
Requires energy
Catalysts
Chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur
Synthesis reaction
A+B -> AB
Decomposition reactions
AB -> A+B
Exchange reactions
AB+CD -> AD+CB
Reversible reactions
AC A+C
Metabolism
Sum total of all chemical reactions in the body
Inorganic compounds
Lack carbon
Tend to be simpler compounds
Salts, water
Organic compounds
Contain carbon
Most are covalently bonded
Carbohydrates, lipids, proteins, nucleic acids, adenosine triphosphate(ATP)
Water
Most important and abundant inorganic compound in all living systems
Salts
Easily dissociate into ions
Vital to many body functions
Include electrolytes which conduct electrical currents
Dissociation
Acid, base or salt separates into ions and becomes surrounded by water molecules
Carbohydrates
Contain carbon, hydrogen, oxygen
Include sugar and starches
Classified according to size
Monosaccharides
(Carbohydrate) simple sugars
Disaccharides
(Carbohydrate) 2 simple sugars joined by dehydration synthesis
Polysaccharides
(Carbohydrate) long branching chains of linked simple sugars
Lipids
Contain carbon, hydrogen, oxygen
Carbon and hydrogen outnumber oxygen
Insoluble in water
Triglycerides
(Lipid) most plentiful lipids in the body and provide protection, insulation, and energy
Phospholipids
(Lipid) form cell membranes
Are amphipathic with both polar and nonpolar regions
Steroids
(Lipid) for example cholesterol (found in cell membrane and needed for synthesis of other steroids, bile salts, vitamin D, and sex hormones
