chemistry

II. Chemistry Comes Alive
1) Basic chemistry
a) Matter and energy
i) Matter- Anything that occupies space and has mass(weight)
ii) Energy- The ability to do work(various forms):chemical, electrical, mechanical, radiant,
b) Composition of matter: Atoms and elements
i) Basic terms
(1) Elements-Fundamental unite of matter (96% of the body is made from four elements; carbon, oxygen, hydrogen, nitrogen.)
(2) Atoms- Building blocks of elements.
(3) Atomic symbols

ii) Atomic structure (See Figs. 2.1& 2.2)
(1) Nucleus
(a) Protons- Inside the nucleus(+)
(b) Neutrons- Inside the nucleus(neutral)
(c) Electrons -Outside the nucleus(-)
(2) Isotopes

iii) Major elements of the human body (See Table 2.1)
iv) Identification of elements
(1) Atomic number- Equal to the number of protons that the atom contains.
(2) Mass number- Sum of the protons and neutrons.
(3) Atomic weight- Close to mass number of most abundant isotope, atomic weight reflects natural isotope variation.
(4) Isotopes- Have the same number of protons, vary in number of neutrons.
(5) Radioactivity- Process of spontaneous atomic decay, heavy isotope, unstable, as it decomposes it becomes a more stable isotope.

c) Molecules and Mixtures
i) Molecules- Two or more like atoms combined chemically.
ii) Compounds- Two or more different atoms chemically combined.
iii) Mixtures

d) Chemical bonds- Unite atoms
i) The role of electrons in chemical bonding
(1) Electron shells-Electrons occupy, each shell has distinct properties(number of electrons has an upper limit)
(2) Energy levels-Closest to the nucleus are most strongly attached.
(3) Filling of electron -Shells closest to the nucleus fill first
(a) Valence shell- Bonding involved interactions between electrons in the outer shell(valence shell), full valence shells do not form bonds.
(b) Shells farther from nucleus can hold more electrons.
(c) Rule of eight = rule of octet
(4) Inert elements (See Fig. 2.5a)- Outer shell is completely full
(5) Active elements-If valence shells are not full they are unstable; gain, lose or share elements, allow for bond formation which produces stable valence.

ii) Types of chemical bonds
(1) Ionic bonds (See Fig. 2.6)- Form when electrons are completely transferred from one atom to another.
(a) Transfer of electrons
(b) Ions-Charged particle.
(c) Anions-Negative
(d) Cations-Positive
(e) Either donate or accept electrons.
(2) Covalent bonds (See Fig. 2.7)-Shared electrons
(a) Sharing of electrons
(b) Types
(i) Single covalent bond- Share one pair of electrons
(ii) Double covalent bond-Share two pairs of electrons
(iii) Triple covalent bond-Share three pairs of electrons
(c) Polar(have a positive and negative side) and nonpolar(electrically neutral as a molecule) molecules (See Figs. 2.8)
(i) Electronegativity
(ii) Electropositivity

(3) Hydrogen bonds (See fig. 2.10)- Weak chemical bonds. Hydrogen is attracted to the negative portion of polar molecule. Provides attraction between molecules, like a magnetic force.

e) Chemical reactions (See Fig. 2.11)
i) Chemical equation
(1) Reactants
(2) Products

ii) Types
(1) Synthesis or anabolic reactions (endergonic)- (A + B -> AB)… Atoms or molecules combine, energy is absorbed for bond formation.
(2) Decomposition or catabolic reactions (exergonic)-(AB -> A+B)…molecule is broken down, chemical energy is released.
(3) Exchange or displacement reactions –(AB + C-> AC + B)…involves both synthesis and decomposition reactions, switch is made between molecule parts and different molecules are made.

iii) Reversibility of chemical reactions
iv) Rate of chemical reactions
(1) temperature
(2) particle size
(3) concentration
(4) catalysts/enzymes

2) Biochemistry
a) Organic compounds- Contains carbon, most are covalently bonded( C6H12O6- glucose)
b) Inorganic compounds- Lack carbon, tend to be simpler compounds, (H2O- water)
i) Water (Fig. 2.8 & 2.9)(H2O)- most abundant inorganic compound, high heat capacity, polarity/solvent properties, chemical reactivity, cushioning.
ii) Salts (See Fig. 2.12)- Easily dissociate into ions in the presence of water, vital to many body functions, include electrolytes which conduct electrical currents
iii) Acids and bases (See Fig. 2.13)
(1) Acids-Release hydrogen ions(H+), are proton donors
(2) Bases-Release hydroxyl ions(OH-), are proton acceptors
(3) pH (Fig. 2.12)-7= neutral. Less than 7= acidic. More than 7=base.
(a) Acidic solutions
(b) Basic solutions
(c) Neutral solutions
(d) Neutralization reaction-Acid and bases react to form water and salt
(4) Buffers-A chemical that can regulate pH change

c) Organic compounds
i) Carbohydrates (See Figs. 2.13)-Contains carbon, hydrogen, and oxygen. Include sugar and starches.
(1) Monosaccharides = simple sugars
(2) Disaccharides = double sugars-Two simple sugars joined by dehydration synthesis.
(3) Polysaccharides = polymers of simple sugars

ii) Lipids (See Fig. 2.15)(fat)- Contains carbon, hydrogen, and oxygen. Carbon and hydrogen out number oxygen, insoluble in water. .
(1) Neutral fats = triglycerides- composed of fatty acids and glycerol, source of stored energy
(2) Phospholipids- Form cell membranes
(3) Steroids-Include cholesterol, bile salts, vitamin D, and some hormones

iii) Proteins (See Fig. 2.16 & 2.17)-made of amino acids, contains carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur. Account for over half the body’s organic matter. Play a vital role in cell function. Act as enzymes, hormones, and antibodies
(1) Amino acids
(2) Structural levels of proteins
(a) Primary structure
(b) Secondary structure
(c) Tertiary structure
(d) Quaternary structure

(3) Fibrous versus Globular proteins
(4) Protein denaturation
(5) Enzymes
(a) Characteristics
(b) Mechanism of actions (See Fig. 2.18)

iv) Nucleic acids (See Fig. 2.19)-Provides blueprint of life
(1) Nucleotides
(a) Nitrogen-containing bases-Make DNA and RNA
(i) A- Adenine, C-Cytosine, G-Guanine, T-Thymine, U-Uracil
(b) Sugar
(i) Ribose (RNA)
(ii) Deoxyribose (DNA)
(c) Phosphate group
(2) Types
(a) Deoxyribonucleic acid DNA

(b) Ribonucleic acid RNA

v) Adenosine triphosphate ATP (See Figs. 2.20 & 2.21)- Chemical energy used by all cells, energy is released by breaking high energy phosphate bonds, ATP is replenished by oxidation of food fuels.