Chemistry of Life

Small to largeAtoms

Element

Molecule

Macromolecule

Cells

Tissues

Organs

Organism

Small to largeAtom: Smallest possible particle of an element

Element: A pure substance that can not be broken down into other substances.

Molecules: Two or more atoms held together by bonds

Macromolecule: a very large molecule, Protein, carbohydrate, Lipid, Nucleic Acid

Cells: Basic unit of living matter

ChemistryAn atom contains; protons, neutrons, and electrons

Atomic number: the number of protons found in the nucleus of an atom

Periodic Table of Elements: An arrangement of elements based on their atomic number and mass

Elements are also placed due to the number of electrons in the outer shell

Electrons and bonding

The number of electrons in the outer shell determines how an element will react with another.

Elements want to have “full” outer shells.

To have a full outer shell an element will either share or transfer electrons

Ionic Bonding: elements transfer electrons

Covalent Bonding: elements share electrons

Water properties

WaterAll living things are dependent on water

Cells are 70% to 95% water

Water is the only compound found on earth in all 3 forms

Water is one oxygen covalently bonded to two hydrogen's.

Although this is a covalent bond the oxygen pulls the shared electrons closer to itself making it more negative and making the hydrogen more positive.

Water structure

Waters life-supporting properties

Cohesion: The tendency of molecules of the same kind to stick to one another.

Important in plants because as water evaporates it pulls itself upward in plants.

Adhesion: Attraction that occurs between unlike molecules.

Important because water sticks to the sides of the plant tubes and helps combat gravity.

Waters life-supporting properties

Temperature moderation: Water has a very strong ability to resist change in temperature due to hydrogen bonding between molecules

Water allows for temperature regulation of the world by staying cool in the summer and warm in the winter

Waters life-supporting properties

Ice: the solid form of water that is lower density than the liquid form. As water freezes the molecules move further apart.

Important because it allows animals to continue to live under frozen water instead of being frozen from the bottom up.

Waters life-supporting propertiesWater has a great ability to

dissolve other substances.

Water is the universal solvent

Solvent: The substance that dissolves another substance

Solute: The substance that is being dissolved

Solution: A uniform mixture of two or more substances.

Acids, Bases, Buffers, Ph

pH Scale

Water sometimes breaks into ion’s of H+ and OH-

Hydrogen ion(+) and Hydroxide ion(-)

These ions are what determine whether something is an acid or base.

The pH scale is an exponential scale showing acids and bases.

Ph Scale

Scale from 0 to 14

each step is 10x more than the next

0-6 is Acidic

7-8 is neutral

8-14 is Basic

LE 2-15

Acidic solution

OH

H+

H+H+

H+OH

H+ H+

H+

OH

OH

OH

OH

OH

H+

H+

H+

H+

H+H+

Incre

asin

gly

AC

IDIC

(Hig

her

con

cen

trati

on

of

H+ )

Neutral solution

OH

OH

OH

OH

OH

OH

H+

H+

Basic solution

NEUTRAL[H-]

pH scale

Lemon juice, gastric juice

Grapefruit juice, soft drink

Tomato juice

Human urine

Pure waterHuman blood

Seawater

Milk of magnesia

Household ammonia

Household bleach

Oven cleaner

Incre

asin

gly

BA

SIC

(Low

er

con

cen

trati

on

of

H+ )

OH

OH

OH

OH

OH

OH

H+

H+

Basic solution

Milk of magnesia

Household ammonia

Household bleach

Oven cleaner

Incre

asin

gly

BA

SIC

(Low

er

con

cen

trati

on

of

H+ )

Bleach

Milk of magnesia

AcidsAn acid is any substance that gives off H+ to the solution

Ex: lemon juice, stomach acid

Acidic solution

OH

H+

H+H+

H+OH

H+ H+

H+ H+

Incre

asin

gly

AC

IDIC

(Hig

her

con

cen

trati

on

of

H+ )

pH scale

BasesA base is a compound that removes H+ from the solution by giving off OH- to bond with the H+

Ex: Soap, Bleach, Oven cleaner

OH

OH

OH

OH

OH

OH

H+

H+

Basic solution

Milk of magnesia

Household ammonia

Household bleach

Oven cleaner

Incre

asin

gly

BA

SIC

(Low

er

con

cen

trati

on

of

H+ )

BufferCells are very sensitive to H+ and OH- ions. Even a slight change in pH will affect a cell.

A buffer will accept H+ ions when they are too high and will donate H+ when they are too low.

Blood is a great example of a buffer

OH

OH

OH

OH

OH

H+ H+

H+

H+H+

Neutral solution

NEUTRAL[H-]

Tomato juice

Human urine

Pure waterHuman blood

Seawater

Chemical Reaction

The breaking of old and forming of new bonds to make new chemical substances.

Reactant: The starting materials

Product: The ending materialsReactants Product

Chemical reaction

In a chemical reaction the atoms are not destroyed or created, just rearranged.

H + H + O = H2O

Ions

Ions are created when an electron is lost or gained

Elements that lose an electron are positive ions (H+) due to the loss of a negative charge.

Elements that gain an electron are negative ions (H-) due to the gaining of a negative charge

Chemistry of LifeCarbon is the one element required for life

Any Carbon based molecule is considered an organic molecule

Each of the four macromolecules start with Carbon as the basis.

Carbohydrates

Lipids

Proteins

Nucleic acids

MacromoleculesCarbohydrate: Complex sugars made up of Carbon, Oxygen and Hydrogen

Starch: a large chain of sugars

Energy source of cells

MacromoleculesLipids: Water avoiding compound made up of Carbon and hydrogen chains

Cholesterol: An essential lipid molecule needed for cell membranes.

Lipids act as a barrier that contains the liquid parts of the cell. They also act as chemical messengers in the form of hormones.

MacromoleculesProteins: A large molecule made up of amino acids

Amino acid: A small molecule that is made up of Carbon, Hydrogen, Nitrogen, and Oxygen.

Proteins are large chains of amino acids that bond together and then fold to create useable cell parts.

Proteins also make up enzymes which speed up chemical reactions.

MacromoleculesNucleic Acids: A large molecule made up of smaller molecules called nucleotides.

Nucleotides: Small molecules made up of a sugar, a nitrogen base, and phosphate

Nucleic acids are what our DNA or genetic material is made of

With out nucleic acids our body would not have directions and could not function.

Proteins and Enzymes

Function of Proteins

Made up of amino acids

Responsible for most day to day functions of all cells

Amino acids link together and form a long chain

Protein ShapeThe long Amino acid chain folds to make the protein useable

A proteins shape is changed by its surroundings

A protein that is outside of its normal environment will be denatured (misshapen)

Proteins to Enzymes

A protein sometimes works as an enzyme

An enzyme speeds up chemical reactions in our bodies

An enzyme speeds up a reaction by making it easier.

This is done by lowering the activation energy

EnzymeEnzyme: A protein that speeds up chemical reactions