Wilkerson BIO 2100 Unit 4 Complete Note Guide Disinfectants, Antiseptics & Growth Curves – Graded A+ 2026

Vocabulary to define Temperature • Psychro-meaning cold • -phile-fondness for a specific thing. • Meso-meaning middle, intermediate • Thermo-meaning heat • Hyper-meaning over, beyond, above pH • Neutro-not on either side • Acid-pH below 7 • Alkaline-pH above 7 Osmotic Pressure • Osmotic Pressure-The osmotic pressure of a solution is the pressure difference needed to stop the flow of solvent across a semipermeable membrane such as cell membrane. • Hypotonic solution-The solution outside the cell whose concentration of solutes is lower than the inside the cell. • Isotonic solution-The concentration of solutes outside the cell is qeual to the concentration of solutes inside the cell • Hypertonic solution-The solution outside the cell has a higher concentration of solutes than inside the cell • Halo-meaning or related to salt • Baro-meaning pressure Oxygen • Aerobe-An organism that requires free oxygen for life • Anaerobe-An organism that does not require free oxygen to live • Obligate-meaning necessary; essential • Facultative-Live under more than one specific set of environmental conditions. • Aerotolerant-Does not require oxygen but tolerates the presence of oxygen. Nutrient Requirements • Carbon -Structural backbone of carbohydrates, proteins, lipids, nucleic acids. It is source of energy for some organisms • Nitrogen-An essential component of nucleic acids, proteins, and ATP. • Phosphorous-A key component in nucleic acid synthesis and phospholipids. • Oxygen-An element essential for aerobic respiration and resulting ATP production. • Trace Elements-Small amounts of minerals needed for cell function. • Organic Growth Factors-Essential organic compounds not synthesized by an organism but necessary for cellular function • Carbohydrates-Molecules made up of carbon, hydrogen, and oxygen whose primary function is to provide energy for the cell. • Lipids-Made of carbon, oxygen, and hydrogen atoms and used as energy and found in the phospholipid portion of the membrane. • Nucleic Acids-Made up of a nitrogenous base, a pentose, and a phosphate group and includes DNA and RNA. • Proteins-Organic molecule containing carbon, hydrogen, oxygen, and nitrogen. Multipurpose molecule in cells. Microbial Growth Requirements Temperature Minimum Growth Temp-the lowest temp at which the species will grown Optimum Growth Temp-the temp at which the species grows the best Maximum Growth Temp-the highest temp at which the growth is possible Differentiate: • Psychrophiles-organisms that can grow at 0 degrees C & lower temps. Their optimum growth is close to 15 degrees C . They do not survive above 20 degrees C, are important decomposers in colder climates. Psychotrophs are also part of this group but range in temp from 4 degrees C to 25 degrees C. • Mesophiles-organisms that prefer moderate temps with optimal growth temps ranging from 20- 45 degrees C. This range includes the core body temp (37 C) Normal human microbiota & pathogens are found in this category. • Thermophiles-organisms with optimum temps of 50 C and maximum temps at 80 C. They can be found in hot springs, geothermal soils, and compost piles. • Hyperthermophiles-prefer extreme temps with a growing range from 80-110 C but some can survive at 121 C. Hydrothermal vents are an example of extreme environments. pH Differentiate • Acidophile-microorganisms that grow optimally at pH less than 5.55. “Sulfolobus spp. Isolated from sulfur mud fields and hot springs in Yellowstone National Park are extreme acidophiles.” • Neutrophile-organisms that grow optimally at a pH 1 or 2 units above a pH of 7. Most bacteria grow best in this range and a way of preventing food spoilage from bacteria can be to preserve it though pickling (pH about 4). • Alkaliphile-organisms with an optimum pH between 8.0 & 10.5. Vibrio cholerae grows at pH of 8.0