Ions, Isotopes, and Chemical Bonds

• Every element possess a unique number of protons.
• If the amount of protons changes, it would create an entirely different element.
• Changing the amount of electrons of an element by donating to or gaining them, will result in an ion.
• An ion results when an atom gains or loses electrons.
• An isotope results when the amount of neutrons in an element changes.
• An atom has no overall electric charge.
• The amount of electrons in the outer shell will determine how an element will react chemically.

Matching Definitions

• Covalent Bonds: Strong chemical bonds where two atoms equally share electrons.
• Ionic Bonds: Bonds where an exchange of electrons occurs due to one atom donating an electron, and the other accepting an electron; present in the formation of NaCl (table salt).
• Polar Covalent Bonds: Bonds where electrons are shared unequally, creating partial positive and negative charges on the atoms; bonds formed in the molecule CCl4.
• Hydrogen Bonds: A weak attraction between a hydrogen atom and an electronegative atom; also, bonds form between hydrogen and oxygen within a water molecule.
• Peptide Bonds: Covalent bonds that join together amino acids in proteins by a dehydration reaction; bonds present in a polypeptide chain; bonding occurs in the secondary structure of protein.

Diagram information

• The diagram is of an atom.
• Count the protons and neutrons to determine the element.

Macromolecules

• Polymers: chains of repeating units.
• Dehydration synthesis/condensation reaction: A reaction where water is removed to form a new bond.
• Hydrolysis: A reaction where water is added to break a bond.
• Isomer: Molecules with the same molecular formula but different structures and properties.

Lipids

• Unsaturated fats have double bonds, while saturated fats do not.
• Lipids store energy
• Glycerol is an alcohol with three carbons, each bearing a hydroxyl group, while fatty acids are long hydrocarbon chains with a carboxyl group at one end.
• Lipids are formed through dehydration reactions.

Carbon

• Carbon can form four bonds.
• These bonds are covalent.
• Carbon chains can differ in length, branching, double bond position, and presence of rings.

Organelles

• Eukaryotic cells contain membrane-bound organelles, while prokaryotic cells do not.
• Endosymbiosis: A theory that explains the origin of eukaryotic cells from prokaryotic organisms.