Chemistry of Life - Pt. 1

element

matter in its simplest form (sodium, potassium, etc.)

SPONCH - Elements of life

atom

the smallest unit of an element, consisting of protons, neutrons, and electrons, which defines the chemical properties of that element.

made of subatomic particles

Bohr model

Atomic number = how many protons

Mass number = neutrons + protons

Atomic mass = average weight of atoms, USUALLY DECIMALS

Ion

an atom with a charge (positive/negative)

cations

positively charged ions formed when an atom loses one or more electrons/has more protons than electrons.

anions

negatively charged ions formed when an atom gains one or more electrons/has more electrons than protons.

compounds

molecules that have more than one type of atom bonded together. They can be either ionic or covalent.

variations in carbon skeleton

1. length

2. branching

3. double bonds

4. rings

isomers

same molecular formula but different structures

structural, geometric, enantiomers

structural: differ in covalent arrangement

geometric: spatial arrangement (cis cis trans trans)

enantiomers: mirror images (left and right hand)

covalent bonds

sharing of electrons to bond

non-polar covalent - electrons shared equally (hydrogen molecule)

polar covalent - not shared equally, results in a negative and positive side (water molecule)

ionic bonds

bonding from attractive forces (negative & positive)

between cations and anions

organic compounds vs inorganic

organic - found in all living organisms, typically have carbon and hydrogen

inorganic - do not consist mainly of carbon and hydrogen; often derived from non-living sources.

amino group

NH₂ attached. Forms amino acids. Other compounds containing amino groups called amines.

carbonyl

Carbon double bonded to oxygen. Middle is ketone, aldehyde is all de way at de end

Makes a compound hydrophilic and polar

hydroxyl

Oxygen and hydrogen

present in alcohols

hydrophilic and polar

carboxyl

carbonyl + hydroxyl

acids - donate protons to other compounds (carboxylic acids)

phosphate group

ATP, ADP, GTP

Acidic

sulfhydryl group

Important in structure & stability of proteins

methyl groups

only non polar functional group

CH₃

stops reactions

polar vs non polar

polar are hydrophilic (love)

non polar are hydrophobic, neutral bc shared equally (fear)

hydrogen bonding

Attractive force between a positive hydrogen atom and electronegative atom, essential for water properties and protein structure.

Van der Waals Interactions

“hot spots” created from movement of electrons in constant motion

cohesion vs adhesion

cohesion: water molecules sticking to themselves

adhesion: water molecules sticking to other substance (hydrogen bonds)

capillary action: water moving up plants

Evaporative cooling

“hot” molecules leave as a gas, “cool” molecules stay liquid

surface of object is cooler after evaporation

takes a lot of energy to change temp. of water

sweat lowers body temp.

“heat bank” - absorb and release large amounts of heat

Surface Tension

caused by cohesion

how difficult to break or stretch surface of liquid, water fairly great

ex: water strider

universal solvent

water dissolves more substances than any other solvent

colloid - suspension of particles in liquid

ice

solid water less dense than liquid, so ice floats

Macromolecules

carbohydrates, lipids, proteins, nucelic acids

made up of polymers which are made up of monomers (joined by covalent bonds)

dehydration synthesis

forms macromolecules

releases water molecule to the reaction

making from the polymers’ structure (H⁺ + OH)

hydrolisis

break down macromolecues

addition of water to the reaction

consumption from the polymers' structure. (H⁺ + OH)

acids vs bases

acids to the left of pH (0-7), more H⁺, donates

bases to the right of pH (7-14) accepts protons