Dr. William P. Ventura
Bacteria and Archaea include organisms that are PROKARYOTIC - contain no nucleus.
All other organisms belong to domain - Eukarya - contain a nucleus.
Domains are further subdivided into KINGDOMS. It is generally accepted that there are 5 KINGDOMS.
Kingdoms
Bacteria - lack intracellular structures called organelles; do contain ribosomes; NO NUCLEUS but has DNA = prokaryotes.
Protista - single celled eukaryotes; contain algae (usually live in water).
Fungi - decomposers (break down and absorb) some are saprophytes - live on organisms no longer alive; some are parasites - live on living organisms.
Plants - autotrophs = photosynthesizers - use carbon dioxide and sunlight energy and water to make glucose. LAND PLANTS - even single celled ones.
Animals - heterotrophs - get food by eating and digesting other organisms. Some are consumers and some are decomposers.
Two major types - invertebrates - lack backbones; and vertebrates - have backbones.
Kingdoms further sudivided into Phylum - Class - Order - Family - Genus - Species.
Genus and Species name used in Binomial Nomenclature. Humans Genus = Homo
Species = sapiens. Hence name is Homo sapiens.
Slides in lab will have either Genus name or both names.
Organization of life's levels
Ecosystem = all organisms living in an area Plus nonliving physical components needed to support life.
Community = all organisms
Population = all individuals of one species
Organism = an individual living thing
Organ systems = all systems found in an organism
Organ = heart of circulatory organ system; brain of nervous organ system
Tissues = all tissues found in an organ system
Cell = unit of living matter surrounded by a membrane.
Molecules = combinations of atoms. Includes DNA and RNA, etc.
Atoms = simplest particle of matter
ATOMIC NUMBER REPRESENTS TOTAL NUMBER OF ELECTRONS OR PROTONS.
ATOMIC WEIGHT represents total number of neutrons and protons = particles in nucleus of atom.
Electron arrangement determines the chemical properties of an atom.
BONDS represent sharing of electrons between atoms.
An IONIC BOND is one that involves a sharing of two electrons between 2 atoms. When the bond is broken one atom gains an electron (becomes negatively charged) and the other loses an electron and becomes positively charged.
Example, Sodium (Na) - Chloride (Cl) is known as sodium chloride it is composed of the atoms sodium and chlorine. Two electrons are shared between sodium and chlorine. When the bond is broken sodium becomes positive (it lost one electron) and chlorine becomes negative (it gains one electron). Because we now see Na+ and Cl- formed we know there was an ionic bond present initially between sodium and chlorine. The positive and negative substances formed are called IONS.
A COVALENT BOND is one that involves a sharing of two electrons between 2 atoms. When the bond is broken each atom reclaims the electron used to form a bond. Example, carbon-carbon when broken yields carbon atom plus carbon atom - no charges present since each atom reclaimed the electron forming the bond.
Covalent bonds can be subdivided into POLAR and NONPOLAR. These terms refer to the condition in the bond while it exists.
A nonpolar covalent bond means the two electrons are shared equally between the atoms while bonded.
A polar covalent bond means the two electrons are shared unequally while the bond is present. The electrons hover nearer one atom; this atom takes on a partial negative charge and the other atom in the bond relationship takes on a partial positive charge.
REMEMBER, WHEN COVALENT BONDS ARE BROKEN THE ELECTRONS RETURN TO THE ORIGINAL ATOMS - SO NO IONS ARE FORMED.
Water is composed of H-O-H. When it breaks up you get H+ plus (O-H)-. Thus we see that one bond in water is ionic. The other in (O-H)- is polar covalent.
When we look at H-O-H interacting with H-O-H, that is, water with water, the hydrogen of one water molecule with hover near the oxygen of another water molecule. This creates an attraction referred to as hydrogen bonding. While not specifically a bond it is still called hydrogen bonding. It is easiest to remember as water coming nearer to water thus creating the uniqueness of water in nature.
Remember water can exist in 3 physical states: solid, liquid, or gas.
Definitions:
A SOLUTION is a liquid containing water and usually some dissolved solid. The liquid is called a solvent and the solid - a solute.
When we look at water a very small amount will break apart to form H+ ions and 0H- ions. We use this process to define pH ( a measure of the hydrogen ions). Water breaks apart to form 0.0000001 H+ and 0.0000001 OH- . It is easier to visualize 0.0000001 as 1 x 10-7.
Thus, when water dissociates (breaks apart) we see 1x10-7 H+ and 1x10-7 OH- ions.
The concept of pH is basically looking at the number associated with the base 10. In the case of water the pH would be 7 because of the 7 in 1x10-7.
By definition water is neutral because it forms the same number of H+ as OH- ions.
If the pH is less than 7 ( such as 6,5,4, etc) it is referred to as an ACID solution. If the pH is greater than 7 it is referred to as ALKALINE or BASIC.
PROKARYOTES - unicellular organisms having no membrane-bounded organelles or nucleus.
EUKARYOTES - organisms having organelles and nucleus founded by membranes.
PARASITES - organisms that feed on other living organisms.
SAPROPHYTES - organisms that feed on dead organisms.
aerobic - oxygen environment or more significantly using oxygen at the cellular level.
anaerobic - no oxygen or more importantly not using oxygen at the cellular level.
glycolysis - anaerobic process - start with glucose end with either pyruvic acid or lactic acid. Remember electrons carried by NADH to electron transport chain and chemiosmosis to yield ATP.
Kreb's cycle or citric acid cycle - start with acetyl coenzyme A end with Carbon dioxide. Again NADH and FADH2 carry electrons to electron transport system to yield ATP.
The electron transport system uses hydrogen ions, electrons and oxygen to yield water and ATP.
Alcoholic fermentation = glucose to ethanol via glycolysis.
Lactic acid fermentation is glucose to lactic acid via glycolysis.
Building muscle is an example of anabolism.
Substrate level phosphorylation occurs in glycolysis and the Krebs cycle.
The bridge between glycolysis and the Krebs cycle is the conversion of pyruvic acid to acetyl CoA.
