Chapter 2 - The Chemistry of Life (My Notes: P1)

4 major body elements

CHON

7 mineral elements

Na, K, Cl, Ca, Mg, P, S

Trace elements

Fe and I (iron and iodine)

What is the max electrons for the first electron shell?

2

What is the max amount of electrons for any electron shell besides the first one?

8

Atom

smallest unit of an element

What are the 3 subatomic particles?

protons, neutrons, electrons

What is the nucleus made up of?

protons and neutrons

The atomic number (bottom) is equal to the number of what?

Protons

The mass number (top) is equal to the number of what?

# of protons + # of neutrons

If the number of neutrons changes, what is created?

isotope

Isotope

same element, different versions

Are most isotopes radioactive?

NO

Radioactive isotopes are known as?

radioisotopes

What makes radioisotopes radioactive?

high energy and unstable

Mixture

a combo of elements

3 types of mixtures

solution, suspension, colloid

solution

substances stay mixed (ex: salt water)

Suspension

one substance does NOT stay dissolved (ex: blood, liquid antibiotic)

Colloid

large particles that stay in mixture, usually thicker (ex: milk)

-proteins and fats

Solute

substance being dissolved in a liquid

Solvent

liquid that dissolves the solute

Chemical bonds form between ?

individual atoms

3 types of chemical bonds

molecule, compound, macromolecule

Molecule

2 or more atoms chemically bonded

Compound

atoms are different elements (ex: NaCl)

Macromolecule

protein, carbs, DNA, fats

What determines how atoms are chemically combined?

# of electrons in the valence (outer) shell

Chemical bonds

-electron shells want to be full

-give away electrons, accept electrons, and share electrons

Inert atoms

-do NOT form chemical bonds

-valence shell is already full

-Noble gases

Reactive atoms

form chemical bonds to fill valence e^- shell

Metals

-give away electrons

-positively charged (cations)

Cation

positively charged atom ex:) Ca²⁺

Anion

negatively charged atom ex:) Cl^- , O^2-

Nonmetals

-need more electrons

-accepts and shares electrons

-negatively charged (anion)

Electronegativity

how strongly an atom attracts electrons

-increases as you go up and right on PT

Most Electronegative

1. Flourine

2. Oxygen

least electronegative

metals

Oxygen

-greedy for electrons

-does NOT share them equally

Ionic Bonds

form between oppositely charged atoms, forms a salt

Covalent Bonds

share electrons between atoms

strongest bonds

2 atoms can share up to 3 electrons

Nonpolar covalent bonds

-atoms share electrons equally

-due to: similar electronegativity, two of the same atom, C & H share equally

Lines for non polar covalent

| or _

Lipids

fats and oils

True or False? non polar substances do not mix well with water

true

Hydrophobic

does NOT mix well with water

Polar covalent bonds

-atoms share electrons unequally

-one atom is more electronegative

Dipole

two different charges on one molecule

True or false? polar substances mix well with water

true

Hydrophilic

mixes well with water

Hydrogen Bonds

forms between 2+ molecules (not atoms!)

-weak attractions, breakable

-oxygen from one molecule bonds with hydrogen from hydrogen from another

chemical reactions

make/break a chemical bond

energy

capability to do work/make change, changes form

3 types of energy

kinetic, potential, chemical

kinetic energy

energy of motion

potential energy

stored energy

chemical energy

energy stored in the bonds of food

forms of energy

chemical, heat, electrical, radiant, mechanical (CHERM)

anabolic/synthesis reactions

makes a new compound, dehydration reaction (hydrophobic)

catabolic/decomposition reactions

break down a compound, condensation reaction (hydrophilic)

exchange reactions

swap or “exchange” parts of 2 compounds

oxidation-reduction reactions

electrons are exchanged instead of atoms

in an oxidation reduction reaction, the reactant that LOSES E^- is what?

oxidized

in an oxidation reduction reaction, the reactant that GAINS E^- is what?

reduced

Reversible reactions lead to what?

Equilibrium

Most reactions are reversible to do what?

maintain homeostasis