Microbiology 145 midterm Flashcards
midterm test for Microbiology 145
World-changing scientific contributions of Leeuwenhoek
Lens grinder, first discovered the bacterial world, handmade microscopes.
Define “microbes” via definition derived by Leeuwenhoek
“All organisms that are too small to be seen without a microscope”
List six groups of microorganisms
- Fungi
- Protozoa
- Algae
- Bacteria
- Archaea
- Small Multicellular animals
Differentiate between prokaryotic and eukaryotic
- Prokaryotic: Any unicellular organism that LACKS a nucleus, (Bacteria & Archaea)
- Eukaryotic: Any organism made up of cells containing a nucleus composed of genetic material surrounded by a distinct membrane. (animals, plants, algae, fungi, protozoa)
4 questions which propelled research into the “Golden Age of Microbiology”
- Is spontaneous generation of microbial life possible?
- What causes fermentation?
- Heating liquid to kill contaminating bacteria without changing the liquid’s basic qualities so it can be consumed.
- What causes disease?
- How can we prevent infection and disease?
4 steps in the scientific method of investigation
- Group of observations leads a scientist to ask a question about some phenomenon
- Generate a hypothesis
- Design and conduct experiment to text hypothesis
- Accept, reject or modify hypothesis
Significance of Pasteur’s fermentation experiences relative to our world today
Luis Pasteur’s fermentation experiment is relative to our world today because he developed “Pasteurization” which we use frequently. He took grape juice and heated it up just enough to kill most contaminating bacteria without changing the juice’s basic qualities, so that it could be inoculated with yeast to ensure the alcohol fermentation occurred. This began the field of Biotechnology: microbes are intentionally used to manufacture products
Describe the research in public health which led to more effective disease prevention
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List the four questions that are currently used to drive research in the “Age of Modernism”
- What are the basic chemical reactions of life
- How do genes work?
- What roles do microorganisms play in the environment?
- How do we defend against disease?
Define the Atom
Atoms: smallest chemical unit of matter
- Composed of positively charged protons, and negatively charged neutrons
- Electrons: negatively charged particles that exist around the atom nucleus
Electron configuration
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Define: Isotope
atoms of an element that differ in the number of neutrons
Configuration of electrons in a stable atom
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Define: Nonpolar covalent bond
sharing of electrons between atoms of similar electronegativities, so that no poles exist
Define: polar covalent bond
Unequal sharing of electrons
Define: Ionic bond
.Atoms with opposite charges attract and form ionic bonds
Define: Molecule
two or more atoms held together by chemical bonds
Define: Compound
if a molecule contains atoms of more than one atom
3 types of chemical reactions found in living things
- Synthesis: involve the formation of larger more complex molecules
- Decomposition: reverse of synthesis reactions; break bonds within larger molecules to form smaller atoms, ions, and molecules
- Exchange: Involve breaking and forming covalent bonds. Both endothermic and exothermic steps
Acid
Substance that dissociates into one or more hydrogen ions and one or more anions. (lemon juice, black coffee, tea)
Base
Molecule that binds with H+ when dissolved in water (baking soda/bleach)
Salt
Compound that dissociates in water into cations and anions other than H+ and OH-.
Unique characteristics of water that make it useful in human biology
- Surface tension
- Solvent
- Wide range of temperature
- Can absorb heat and evaporate
- Participate in many reactions as reactant of product
Role of a buffer
-Substances that prevent drastic changes in pH
Lipids
hydrophobic organic molecule
-Fats, waxes, phospholipids, steroids
Discuss the 4 principle functions of living cells
- Growth
- Reproduction
- Responsiveness
- Metabolism
Compare & Contrast eukaryotic and prokaryotic cells.
Eukaryotic
- Algae, Protozoa, Animals & Plants
- Nuclear envelope surrounds DNA to make a nucleus
- Membrane-bound organelles
- Large in size (compared to prokaryotes)
- 80s Ribosomes
- Cytoskeleton: cell structure, organize organelles
Prokaryotic
- Bacteria & Archaea
- No membrane bound nucleus
- Make proteins simultaneously from reading genetic code
- Different macromolecules (lipids, carbohydrates)
- Non-membranous organelles
- May have inclusions or endospores
- 70s Ribosomes
- Cytoskeleton: cell structure
Glycocalyses
gelatinous substance that surrounds the outside of the cell
Flagella
long locomotive structure extending beyond the surface of cell for mobility
Fimbriae
sticky, bristle-like projections used to adhere to one another or substances in the environment.
helps form biofilms
Pili
Type of fimbria which is used by bacteria to transfer DNA to another cell
Gram + Cell wall structure
- Thick layer of peptidoglycan outside cytoplasmic membrane
- Techoic acids and lipotechoic acids
- Techoic acids have – charge
- Some have waxy lipids which help them survive drying out
Gram - Cell wall structure
- Thin layer of peptidoglycan
- Second layer
- Inner: phospholipid + protein
- Outer: lipopolysaccharide
- Lipid A: componenet of LPS aka Endotoxin
- Porins: proteins that form channels in second layer
- Periplasmic space: area between the membrane
Describe the phospholipid bilayer found in cytoplasmic membranes and its function
- Phospholipid bilayer: 2 layers of polar molecule and contains integral proteins
- Controls what enters/exits the cell. Defines inside vs. outside of cell. Selectively permeable. Creates a concentration gradient. Electrical gradient.
Diffusion
Net movement of a chemical down it’s concentration gradient
Hypotonic
concentration of solute is lower in comparison
Hypertonic
concentration of solute is higher
Isotonic
equal concentration of solutes
Facilitated diffusion
Proteins in membrane provide a pathway for chemicals to flow
Osmosis
The diffusion of water across the membrane
Active transport
The movement of a substance against it’s electrochemical gradient via carrier proteins and requiring cell energy from ATP
Uniport
one substance transported at a time
Antiport
Simultaneous but opposite, transport of two chemicals
Group Translocation
Active process by which a substance being actively transported across a cell membrane is chemically changed during transport
