Unit 1 - Chemistry of Life

Subatomic particles

protons, electrons and neutrons

Nucleus of an atom

made of protons and neutrons in an orbital

Valence shell

the last orbital in an atom

Valence electrons

electrons inside the last orbital

Atomic mass

the total number of protons and neutrons

Atomic number

the number of protons

O, C, H, and N

components of all living matter

Achieving stability

reason for chemical interactions

Covalent bonds

sharing electrons to achieve stability

Pure elements

substances consisting of only one type of atom. (H₂ , O₂)

Chemical compound

substances that are formed when two or more different elements chemically bond together

Electronegativity

the attraction of an atom to another in a covalent bond

Hydrogen bonds

attraction of a Hydrogen + Electronegative atom with another Hydrogen + Electronegative atom

Ionic bonds

when atom transfer electrons to satisfy their valence shells

Cation

a positively charged ion

Anion

a negatively charged ion

Adhesion

attraction between water and other molecules (xylem in plants)

Cohesion

attraction between water molecules (high surface tension, transpiration pull)

High heat capacity

ability to absorb and release large amounts of heat with only a slight change in temperature (how many C lost per 1 gram).

Crystalline lattice

structure that contains spaces between molecules.

Universal solvent

water dissolves all polar and ionic molecules, facilitating chemical reactions and processes in living organisms.

A mixture

a combination of two or more substances that are PHYSICALLY bonded together

Solutions

a uniform mixture of a solute and a solvent.

Solute

dissolvents that melt into the solution

Solvents

liquids in which solutes dissolve

Aqueous solution

a solution in which water is the solvent

Hydration shell

a layer of water molecules surrounding a solute particle, stabilizing it in solution and preventing it from interacting w/ other molecules

Hydrophilic substances

any substance with affinity (attraction) to water, usually polar or charged.

Hydrophobic substances

substances that repel water, are nonionic and non-polar, or cannot form hydrogen bonds.

Hydrophobic tail

made of non-polar fatty acid chain

Hydrophilic head

made of polar phosphate groups

pH (power of hydrogen)

measuring the concentration of H+ ions in a solution.

Buffer

helps maintain the internal pH of substances

Carbonic acid-Bicarbonate system

buffer system in blood that regulates pH using carbonic acid (H₂CO₃) and bicarbonate (HCO₃⁻)

pH of blood

7.4 (slightly basic)

4 bonds elements

carbon

2 bonds elements

oxygen and sulfer

Location of Sulfer

in proteins

Location of Oxygen and Hydrogen

in all types of macromolecules

3 bond elements

nitrogen and phosphate

Location of Nitrogen

in nucleic acids and proteins

Location of Phosphorus

in nucleic acids and some lipids

Single bond element

hydrogen

Hydrocarbons

organic molecules that consist of carbon and hydrogen atoms (fuel source in biological processes)

Isomers

compounds with the same molecular formula but different structural arrangement of atoms

Structural isomers

same molecular formula but differ in the way atoms are connected or arranged (ex:- straight chain vs a branched chain)

Geometric isomers (trans-cis)

compounds with same atoms and same connectivity but have different arrangements

Cis isomers

isomers with similar groups on the same side of a double bond or ring.

Trans isomers

isomers with similar groups on opposite sides of a double bond or ring.

Enantiomers

isomers that are mirror images of each other, caused by a asymmetrical carbon atom that is 4 bonded.

Estradiol

type of estrogen found in females

Testosterone

the main sex hormone for males

Steroids

a carbon skeleton made up of four infused rings (ex:- estradiol and testosterone)

Chemical groups

groups of atoms that give specific properties and reactions to molecules, (ex:- hydroxyl, carboxyl, amino, and phosphate groups).

Functional group

a specific group of hydrophilic atoms in a molecule that determines its chemical properties and reactions

Hydroxyl group

(-OH) Alcohol, polar

Carbonyl group

(>C=O) Ketone aldehyde, polar

Carboxyl group

(-COOH) Carboxylic acid, or organic acid, polar

Amino group

(-NH2) Amine, polar

Sulfhydryl group

(-SH) Thiol, polar

Phosphate group

(-OPO3^²-) Organic phosphate, polar

Methyl group

(-CH3) Methylated compound, non-polar

ATP

the energy currency in cells

ADP

an energy molecule that converts to ATP

Polymer

a long molecule made up many monomers (bonded by covalent bonds)

Carbohydrates

made from monosaccharides

Proteins

made from amino acids

Nucleic acids

made from nucleotides

Lipids

made from fatty acids and glycerol

Condensation reaction

a reaction where monomers combine to form polymers, releasing a molecule.

Dehydration reaction

When the condensation reaction releases water

Hydrolysis

Breaking down of polymers by adding water

Enzymes

reusable proteins that speed up chemical reactions.

Defensive proteins

protects against disease

Storage Proteins

stores amino acids

Casein

the protein of milk

Ovalbumin

the protein of the egg white

Transport proteins

transport of substances

Hemoglobin

iron-containing protein in blood

Hormonal proteins

coordinates an organism’s activity

Insulin

a hormone secreted by the pancreas that regulates blood sugar by forcing tissues to absorb glucose.

Receptor protein

responds to the cell by chemical stimuli

Contractile and motor proteins

for movement (actin, myosin, cilia and flagella)

Structural proteins

gives support and shape to cells and tissues

Keratin

the protein of hair, horns, feathers and skin appendages

Collagen and elastin

a fibrous framework in connective tissue

Protein structure

amino group, carboxyl group and side chain

Peptide bonds

covalent bonds that link together amino acids, forms when a carboxyl group of one amino acid reacts with an amino group of another

Polypeptides

a chain of amino acids liked together by peptide bonds

Amino acid - Nonpolar

side chains are hydrophobic

Amino acid - Polar neutral

side chains are hydrophilic (slightly charged)

Amino acid - Polar acidic

side chains are hydrophilic (negatively charged, presence of carboxyl group)

Amino acid - Polar basic

side chains are hydrophilic (positively charged, presence of amino group)

Protein - Primary structure

linear sequence liked by peptide bonds

Protein - Secondary structure

parts of the polypeptide chain interact together through hydrogen bonds between atoms of the backbone

Protein - Tertiary structure

the overall 3D shape of a polypeptide

Protein - Quaternary structure

a protein chain made up of two or more polypeptide chain

Alpha helix

a coiled structure held together by hydrogen bonds

Beta-pleated sheet

flat structure where the segments of the chain line side by side, held together by hydrogen bonds

Denaturation

when the weak bonds holding the protein together is disturbed, causing it to unravel and lose it shape, therefore its function