Biochemistry Unit Chapter 2: Chemical Foundations for Cells You can be a chemist without knowing biology, but you can’t be a biologist without knowing chemistry.

I.Basic Chemistry A. Subatomic Particles ChargeMass (AMU) Location Neutron Proton Electron Nearly 0

I. Basic Chemistry B. Atoms The smallest unit of matter that still retain the properties of a given element. Too small to be seen by nearly all microscopes/imaging technology. Each element is represented by a capital letter, possibly followed by a lower case letter. (e.g. H, O, C, Ag, Au)

Basic Chemistry B. Atoms Structure: Nucleus (no membrane or surrounding core) and electron clouds. Just know first three clouds hold: >2 electrons, cloud 1 >8 electrons, cloud 2 >8 electrons, cloud 3 Outer cloud call valence cloud (it reacts with other atoms)

Basic Chemistry C. The Periodic Table 1.Columns represent # of valence electrons (ignore dip)

# of Valence Electrons C – Carbon Na – Sodium Si – Silicon Cl - Clorine

Basic Chemistry C. The Periodic Table 2. Rows equal number of electron clouds

Number of Clouds: Li – Litium H – Hydrogen Si – Silicon Ca - Calcium

Basic Chemistry C. The Periodic Table 3. Reading the Details: Atomic Number - # of Protons Atomic Mass - # of Protons + # of Neutrons Atomic Symbol – Only 1 upper case letter

Complete: P N E O-16 H – 2 H - 3

Basic Chemistry C. The Periodic Table 4. Rush Limbaugh Rule (Boint’s favorite part of chemistry): All electrons what to be like those on the FAR RIGHT (Noble gases). A full outer cloud is known as a stable octet (having 8 electrons).

Basic Chemistry C. The Periodic Table 5. Left side of table are metals Right side are nonmetals Along stair are the metalloids

Basic Chemistry D. Molecules 1.Two or more atoms chemically combined. 2.Mixtures (salt and water) are simply physically mixed, not chemically combined. 3.Molecules are written with no space between atomic symbols (e.g. H 2 O or NH 4 )

II. Key Concepts in Chemistry A. Ions: Atoms with net electric charge. Balanced atom/molecule: # of electrons and protons equal. Ion: Unequal # electrons and protons. Polyatomic Ion: Two or more atoms combined, with the molecule/compound having a overall negative charge. (NO 3 -)

II. Key Concepts in Chemistry B. Isotopes: Atoms of the same element with different numbers of neutrons, thus different atomic masses. Number of protons is ALWAYS constant for an element. Number of neutrons can vary.

Three Isotopes of Hydrogen Protons? Neutrons? AMUs? Chemical Notation?

II. Key Concepts in Chemistry C. Radioactivity: An atom with an unstable nucleus that undergoes decay (lost of subatomic particles) as it transitions to a stable state. Decay of trilium: 3H1 => 3He2 + 0e-1

III. Electrons Negligible mass Exist in clouds of probability, not defined ‘shells’! (ignore the book when they use this term) Basis of Bonds

III. Electrons A.Ionic Bonds: Strong bonds between a metal and nonmetal Two ions joined together Electrons ‘donated’ not ‘shared’ The strongest of the bonds Ionic compounds have high melting points and crystal structures

III. Electrons B. Covalent Bonds: Bond between nonmetals in which electron pairs are ‘shared.’ Not as strong as ionic bonds Compounds form discrete molecules Molecular formula (H 2 O)

III. Electrons B.1. Polar Covalent: A covalent bond in which electrons are unevenly shared, resulting in a electrically balanced molecule (equal number of protons and electrons) but with charged ends. Involves (mainly) F, Cl, O due to their highly electronegative properties

III. Electrons B.1. Polar Molecules

III. Electrons B. 2. Hydrogen bonds: Notably strong polar bonds due to the solo proton in hydrogen’s nucleus.