The Chemical Level of Organization What is matter

The Chemical Level of Organization

What is matter? § § It is anything that takes up space and has mass (weight). Types a) Solids – definite shape and volume b) Liquids – definite volume c) Gases – no definite shape and volume § Changes a) Physical changes – do not change the basic nature of a substance (ice melting) b) Chemical changes – change the composition of a substance (food digestion)

What is energy? § It is the ability to do work or to put matter into motion. § Types 1) Kinetic energy – actually doing work (moving objects) 2) Potential energy – inactive or stored energy (batteries)

What are the energy forms? § Chemical energy – stored in chemical substances § Electrical energy – movement of charged particles § Mechanical energy – moving matter § Radiant energy – travels in waves

What is the composition of matter? § § Elements – unique substance that cannot be broken down into simpler substances (112 in existence) Four Common Elements (96% of body) a) b) c) d) Carbon Oxygen Hydrogen Nitrogen

What is an atom? § It is the building block of elements shown by one or two letters found on a periodic table § Structure 1) 2) 3) Protons – positively charged Electrons – negatively charged Neutrons – no charge

Lewis Dot Diagram

Atomic Vocabulary § Atomic number = number of protons in atom § Atomic mass number = number of protons in atom + number of neutrons in atom § Isotope – same number of protons and electrons but differ in the number of neutrons in the atom (hydrogen, deuterium, tritium)

Atomic Vocabulary § Molecules – two or more atoms that combine chemically (H 2 O) § Compound – two or more different atoms bind together to form a molecule (CH 4) § Chemical reactions – when atoms unite chemically forming chemical bonds

What are chemical bonds? § § It is an energy relationship that involves interactions between the electrons of the reacting atoms. The valence shell or outer energy level is involved in this bonding. 1. 2. 3. First energy shell – holds 2 electrons Second energy shell – holds 8 electrons Third energy shell – holds 8 electrons

What are two types of chemical bonds? 1. Ionic bond – when electrons are completely transferred from one atom to another. This forms two oppositely charged ions (+ and -) § Na. Cl – sodium chloride (table salt) Na = (11 p+, 12 n 0, 11 e-) Cl = (17 p+, 18 n 0, 17 e-)

Type of chemical bond 2. Covalent bond – sharing of electrons between atoms CH 4 (methane), H 2 (hydrogen gas), Cl 2 (chlorine gas)

What are the patterns of chemical reactions? § § Chemical reactions involve the making and breaking of bonds between atoms. Three Types: 1. Synthesis reactions – when two or more atoms combine to make a larger molecule A+B AB (amino acids = protein) 2. Decomposition reactions – when a molecule is broken down into smaller atoms AB A + B (glycogen + glucose) 3. Exchange reactions – both synthesis and decomposition reactions AB + C AC + B and AB + CD AD + CB

What are inorganic compounds? § § Compounds that lack carbon Three Types: 1. Water – most abundant compound in body and universal solvent 2. Salts (electrolytes) – nerve transmission, muscle contraction, blood clotting and metabolism 3. Acids – proton donors (H+) 4. Bases – proton acceptors (OH-)

What is p. H? § It is the concentration of hydrogen and hydroxide ions in various body fluids. The scale runs from 0 to 14. § p. H below 7 = acidic § p. H above 7 = basic or alkaline § p. H at 7 = neutral

p. H scale

What are organic compounds? § § § Carbon-containing compounds Contains the four elements – carbon, hydrogen, oxygen, and nitrogen (CHON) Major Types: 1. 2. 3. 4. Carbohydrates Lipids Proteins Nucleic acids

What are carbohydrates? § § § Sugars and starches Contain carbon, hydrogen, and oxygen Classification: a) Monosaccharides – simple or one sugar (glucose) b) Disaccharides – double sugars (sucrose, lactose, maltose) c) Polysaccharides – long branching sugars ( starch and glycogen)

Carbohydrate Diagrams

What are lipids? § Neutral fats or triglycerides (glycerol and three fatty acid chains) – most abundant source of energy § Phospholipids – found in cell membrane § Steroids (cholesterol) – found in cell membrane

Lipid Diagrams Triglyceride Formation Phospholipid molecule Cholesterol

What are proteins? § 50% of organic matter in body § Building blocks are amino acids (20) § Classification: 1. Fibrous proteins or structural proteins (collagen and keratin) 2. Globular proteins or functional proteins (enzymes, hemoglobin, and hormones)

Amino Acid Structures

What are nucleic acids § Building block is nucleotide a) b) c) Nitrogenous base Sugar (ribose or deoxyribose) Phosphate group § Deoxyribonucleic acid (DNA) – genetic material of the cell nucleus § Ribonucleic acid (RNA) – directs protein synthesis

Nucleic Acid Diagrams nucleotide DNA structure

What are enzymes? § Functional proteins that act as biological catalysts § Increase rate of chemical reaction § End with the suffix (ase)

What is ATP? § Adenosine triphosphate § Chemical energy for all body cells § Structure: a) Adenine base b) Ribose sugar c) Three phosphate groups

Hydrolysis of ATP