Chemistry of Life



Chemistry of Life

Chemistry Review

A. The Nature of Matter

a. Matter= anything that has mass and takes up space

i. Physical Properties= can be observed and measured without changing the identity of the matter (mass, density, color, etc)

ii. Chemical Properties= describe a substance’s ability to change into another substance as a result of a chemical change

B. Molecular Organization

a. Atoms= smallest unit of matter that retains its chemical properties

i. Each and every atom contains the following:

1. Nucleus

a. Protons (+, 1 amu)

b. Neutrons (0, 1 amu)

2. Electron Cloud

a. Electrons (-, 0 amu)

b. Elements= a substance made up of only one type of atom (periodic table of elements)

c. Molecule= bonding between atoms of 1 or more elements, smallest unit of a compound

d. Compound= chemical combination of 2 or more elements in definite ratio

e. Cell= collection of compounds that forms a living unit; smallest unit that can be considered living.

C. The Periodic Table

a. Each type of atom is found as an element on the periodic table

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D. Bonds! Atoms usually need interactions with other atoms to be happy. They interact to completely fill their outer electron orbitals; for most atoms this number is eight (remember the octet rule?)

a. Covalent= atoms share electrons, forms between two nonmetals

i. Polar= results from unequal sharing

ii. Nonpolar= when atoms share electrons equally

b. Ionic= electrons are transferred between atoms to create ions, form between nonmetals and metals

c. Hydrogen= between the H+ region of one atom and the – region of another atom

E. Isotopes= Elements that have the same atomic number, but a different atomic mass due to a different number of neutrons in the nucleus

a. Most elements have several isotopes that exist in nature. These isotopes help scientists and archeologist date fossils, soils, and different samples.

b. Isotopes are also used as markers to track that passage of a substance either in lab or for medical purposes.

c. Isotopes can also be used to treat certain diseases. Iodine-131 is used to treat thyroid cancer, strontium- 89 and samarium-153 are used to reduce cancer induced bone pain.

Chemistry of Life

A. The Essential Elements (These elements are necessary for life)

a. Carbon

b. Hydrogen

c. Nitrogen

d. Oxygen

e. Phosphorus

f. Sulfur

B. Organic vs. Inorganic

a. Organic molecules= compounds that contain a carbon-hydrogen bond (such as C6H12O6- glucose, and CH4- methane)

b. Inorganic molecules= do not contain a carbon-hydrogen bond (compound like CO2, and H20)

C. Organic Molecules

a. Most organic molecules come in two forms: Monomers and Polymers

i. ‘mono’= one, ‘poly’= many

ii. Many may also have ‘di’= two

Types of Organic Compounds

A. Carbohydrates (most abundant)

a. They are organic compounds that contain carbon, hydrogen, oxygen in a ratio 1:2:1 (Glucose is C6H12O6)

b. They are made by plants

c. They are the bodies main source of energy and provide structure in plants

d. They are made up of monomers called monosaccharides ALL END IN –OSE!!

i. Monosaccharides are simple sugars and are easily identifies by their taste.

ii. Common Monosaccharides: Glucose, Fructose, Galactose

iii. Structure: Ring shaped

e. Polysaccharides are complex carbohydrates made of long chains of monosaccharides

i. Starches (bread, cereals, pastas) and Cellulose (plant cell walls)

ii. Sucrose (table sugar) is a disaccharide

f. Monosaccharides link together to form a polysaccharide by dehydration synthesis (losing a water)

g. Polysaccharides breakdown into monosaccharides by the addition of water

h. Contain 4 grams/calorie of energy

B. Lipids

a. Function in hormones, cell membranes, and are used for energy storage

b. They are also steroids, which are chemical messengers

c. Contain C, H, O

d. They are not water soluble, they are hydrophobic

e. Lipids are fats, oils, waxes

f. Lipids are made up of 1 glycerol and 3 fatty acids (they are commonly known as triglycerides)

i. Saturated – have the maximum amount of hydrogens, no carbon double bonds, they are packed very closely together and form a solid at room temperature.

ii. Unsaturated - have carbon double bonds, which cause the tail to kink or turn, because of this they cannot pack closely and will from a liquid at room temperature.

g. Contain 9 grams/calorie of energy

C. Nucleic Acids

a. They are very large linear molecules

b. Contain C, H, N, O, P

c. They function in an organism by storing genetic information and by helping to make proteins.

d. Nucleic Acids are: DNA and RNA

e. Formed from Nucleotides which have:

i. Sugar (DNA= deoxyribose, RNA= ribose)

ii. Phosphate Group

iii. Nitrogen Base (Adenine, Thymine/Uracil, Guanine, Cytosine)

D. Proteins

a. They are complex organic compounds made up of amino acids

b. They are needed for the body to perform correctly

c. Contain C, O, H, N, S

d. They form hair, muscles, cartilage, and nails

e. They make enzymes which control the rate of chemical reactions (we will cover this in great detail later)

f. Proteins are made up of amino acids which have:

i. An amino group (-NH2)

ii. A carboxyl group (-COOH)

iii. Side group which varies in the different amino acids

g. To make a protein two or more amino acids will join together by a peptide bond.

i. When two or more amino acids form together it results in a polypeptide.

ii. There are only 20 naturally occurring amino acids, all proteins come from these 20 amino acids

h. Levels of protein structure:

i. Primary= sequence of amino acids

ii. Secondary= amino acids sequence is folded or coiled

iii. Tertiary= folds and coils bond together to form a 3-D structure

iv. Quaternary= (Complex) Two or more polypeptides bonding together

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