What is your “take away” from Mr. Chesser’s talk yesterday? Catalyst What is your “take away” from Mr. Chesser’s talk yesterday?

Fungal colonies vs. bacterial colonies

Post lab: Why do we need to swab our control dish with distilled water? Was the control effective? Why/ why not? Some quadrants have Zero growth in them. Explain why this is. Why did the growth of the microorganisms vary with location? Are bacteria ubiquitous? How do you know?

Catalyst: List down the following factors in the bacterial culture investigation: Independent variable Dependent Variable Control Constants

Species, kingdom, domain, family, order, genus, phylum DO YOUR BEST:Arrange the following from the largest to the smallest taxon( group) Species, kingdom, domain, family, order, genus, phylum

Taxa/levels of classification

Domains of Life Prokaryotes

Domain Prokarya An Overview

Prokaryotes Vs. eukaryotes Characteristic Eukaryote Prokaryote Genetic Material Location Contained in membrane bound nucleus Free in cytoplasm, attached to a structure called mesosome located in the cell membrane Form Multiple chromosomes Single circular piece of DNA Replication Mitosis & meiosis Binary fission Extrachromosomal DNA In mitochondria Plasmids, small circular taining accessory pieces of DNA containing accessory info, maybe present in the cytoplasm

Prokaryote vs. Eukaryote Characteristics Eukaryote Prokaryote Protein Synthesis Site Rough ER No ER, ribosomes are free in the cytoplasm or attached to the cell membrane Energy site Within membrane- bound mitochondria ETC is located in the cell membrane; no mitochondria Lysosomes Contain hydrolytic enzymes Not present Cell envelope Plasma membrane Cell Wall Lipoprotein membrane;regulates transport Usually absent except for fungi, which contain chitin in the cell wall Lipoprotein membrane; regulates transport Present; imparts rigidity; various types ( gram negative/gram positive)

Archaebacteria Detection of pathogens, amplify/make copies of DNA

Prokaryotes include: Archaebacteria/ archaea “ Extremophiles” Ex: Methanogens – intestines, produce methane from hydrogen Halophiles – salt (Utah’s great Salt Lake) Thermophiles – heat tolerance (Hot Springs, deep sea hydrothermal vents) May have been on Earth for 3.5 billion years Eubacteria – all other bacteria

Archaebacteria Salt crust is colored red by dense colonies of halophilic archaebacteria. Sierra Nevada Halophilic bacteria surviving in salt crystals. Owens Valley, California

Characterizing Eubacteria Bacteria can be characterized by shape

Characterizing Bacteria A. Oxygen requirements a. Aerobic Bacteria require oxygen to support reproduction ex.Esherichia coli B. Anaerobic bacteria reproduce in the absence of oxygen Listeria Clostridium botulinum

Characterizing Bacteria Facultative bacteria reproduce either in the presence or in the absence of oxygen. Salmonella Staphylococcus aureus

Characterizing Bacteria:

Gram Positive Vs. Gram Negative Bacteria

Characterizing Bacteria Bacteria secrete a covering for themselves - cell wall Do not contain cellulose like plant cell walls Mostly made of peptidoglycan (polypeptides bonded to modified sugars) the amount & location of the peptidoglycan are different in the two possible types of cell walls, depending on the species of bacterium

Characterizing Bacteria Some antibiotics, like penicillin, inhibit the formation of the chemical cross linkages needed to make peptidoglycan. These antibiotics don’t outright kill the bacteria, but just stop them from being able to make more cell wall so they can grow. That’s why antibiotics must typically be taken for 7-10 days until the bacteria die (unable to grow) If a person stops taking the antibiotic sooner, any living bacteria could start making peptidoglycan, grow, and reproduce.

Characterizing Bacteria Dr. Hans Christian Gram, a Danish physician, invented a staining process to tell the two types of bacteria apart, and in his honor, this process is called Gram stain.

Gram Stain the amount of peptidoglycan in the cell walls of the bacteria determine how those bacteria absorb the dyes with which they are stained bacterial cells can be Gram+ or Gram -. E.Coli and Strep

Gram Stain Gram+ bacteria have simpler cell walls with lots of peptidoglycan, and stain a dark purple color. Anthrax

Gram Stain Gram- bacteria have more complex cell walls with less peptidoglycan, thus absorb less of the purple dye used and stain a pinkish color instead Pseudomonus aerugenosa E.coli

Gram Stain Gram negative bacteria often incorporate toxic chemicals (called endotoxin) into their cell walls, thus tend to cause worse reactions in our bodies. antibiotics like penicillin are less effective against gram negative bacteria. Ampicillin was developed to treat gram negative bacteria

Gram Stain Gram staining involves a four-part process, which includes: crystal violet, the primary stain iodine, the mordant a decolorizer made of acetone and alcohol safranin, the counterstain