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66 Cards in this Set
- Front
- Back
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What is microbiology? |
The study of microbes
To examine how microbes interact with humans, food and how they can be used by humans |
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Microbe definition |
Small, life-like organisms |
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Microorganisms definition |
Include bacteria, archaea and microbial eukaryotes |
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Robert Hooke |
First to identify mold - suspected fruiting bodies
First to use early microscopes to visualize microorganism - mold |
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Antonie Van Leeuwenhoek |
Father of Microbiology
He made improvements in lens construction that allowed the first description of bacteria |
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Why study microbiology? |
Fast, cheap and easy to grow
Produce enzymes and other molecules for industrial and medical uses
Most have small numbers of genes - easy to study
There is genetic manipulation of single-celled bacteria which is easier than multicellular eukarya |
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What are two microbes that are readily accessible? |
E.coli and S.cerevisae |
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Understanding of life has arisen largely from? and how has it helped? |
From studies of microorgnaisms
Biochemistry, genetics and it can continue to contribute to fundamental knowledge of life processes |
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Microorganisms - relationship with humans - created what? - who evolved from them? - How much of the Earth is comprised of microorganisms?
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- first life on Earth, evolved from them but still connected with them through bodily functions - Created the biosphere that allowed multicellular organisms to evolve - Multicellular organisms evolved from them - >50% of the biomass on Earth is comprised of microorganisms |
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What is the basis of life? |
Metabolism - growth and reproduction
Genetic variation / evolution
Response/adaptation to the external environment
Homeostasis |
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The four macromolecules in microbial cells and their subunits |
Polypeptides - amino acids Nucleic acids - Deoxyribonucleotides and ribonucleotides Lipids - Diverse structures Polysaccharides - sugars |
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When in an DNA extractions, what comes out |
Polypeptides |
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Functions of polypeptides |
Catalyze the vast majority of biochemical reactions in the cell. Other proteins are structural components of cells |
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Functions of nucleic acids: Deoxyribonucleoties |
Informational: DNA provides the instructions for assembly and reproduction of the cell |
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Functions of nucleic acids: Ribonucleoties |
Many functions, most of which are involved in the production of polypeptides. Some serve structural or catalytic functions |
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Functions of lipids |
Structural: make up cellular membranes that form physical boundary between the inside of cell and surroundings and membranes of internal organelles |
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Functions of polysaccharides |
Structural (such as cellulose and chitin) and energy storage (such as glycogen and starch) |
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What makes most of the cell? What makes least of the cell? |
Most: Polypeptides
Least: Nucleic acids |
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What is the purpose of polypeptides? |
building blocks for enzymes and other proteins |
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RNA polymeriase - location - function |
- cytoplasm of bacteria and archaeons, nucleus of eukarya
- produces RNA molecules from DNA template |
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Glycogen phosphorylase - Location - function |
- cytoplasm - conversion of glycogen into glucose monomers |
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K+ channel - location - function |
- Plasma membrane - Passive transport of K+ across the membrane, from an area of high concentration to an area of low concentration |
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Na+ / K+ ATPase - location - function |
- plasma membrane - Active transport of Na+ and K+ across the membrane, from areas of low concentration to area of high concentration |
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Flagellin - location - function |
- bacterial flagellum - monomers polymerize to form flagellum, which aids in bacterial motility |
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FtsZ - location - function |
- Associated with plasma membrane of bacteria - Key component of cell division machinery |
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The Lipid Bilayer |
It is impermeable to many compounds.
It separates cell interior from the external environment
Often embedded with polysaccharides and polypeptides
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Nucleic acids |
DNA and RNA
Critical as storehouses of genetic information |
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All microorganisms classified as either? |
Prokaryotic cell or eukaryotic cell |
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The Phylogenetic Tree |
Divided into three domains
Based on ribosomal RNA sequences
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Nuclear membrane of bacteria, archaea, eukarya |
No, no, yes |
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Membrane-bound organelles of Bacteria, Archaea or Eukarya |
Bacteria: Rare, a few types found in a few species Archaea: Rare, a few types found in a few species Eukarya: Multiple distinct types, found in all species
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Plasma membrane of Bacteria, Archaea, Eukarya |
Bacteria: Similar to Eukarya Archaea: Different from Bacteria and Eukarya Eukarya: Similar to Bactera |
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Cell wall of Bacteria, Archaea, Eukarya |
Bacteria: Found in nearly all species, constructed of peptidoglycan
Archaea: Found in nearly all species, constructed of various materials
Bacteria: Found in nearly all species, constructed of various materials |
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RNA polymerase of Bacteria, Archaea and Eukarya |
Bacteria: Single polymerase
Archaea: Single polymerase, Eukaryal-like RNA pol II
Eukarya: Three main polymerases (RNA pol I,II & III) |
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Histones of Bacteria, Archaea and Eukarya |
Bacteria: Histone-like proteins
Archaea: Yes
Eukarya: Yes |
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Viruses - in relation to other domains - four facts |
Distinct from three domains due to the rRNA
Not considered alive because they don't replicated outside of host cell - need host
Little to no biochemical activity outside of host
Inert and nonreactive outside of a host cell |
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What are microbes? |
Forms of life too small to be seen with the naked eye |
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Origins of Life -oxygen at the beginning, CO2 and N2 |
Earth without life due to high temperature and no oxygen in the atmosphere
Higher carbon dioxide with 48% Nitrogen started 1.9% |
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What is the level of N, CO2, O2 and temperature |
Nitrogen is 79% CO2 is now at 0.4% concn Oxygen is at 21% - enough for us Substantial cooling temperature |
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Electrons in the origin of life |
Had a lot of gases that are burnable with lots of electrongs to give, but not oxygen to take these elelectrons |
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When was cyanobacteria formed?
What happened at 2 billion years ago?
Formation of Earth was when?
When was the origin of life?
When was endosymbiosis |
3-3.5 billion years ago
Oxygen was established but not enough to go through respiration
4.5 billion years ago
4 billion years ago
Between 1.5 - 2 billion years ago where 1.5 billion years ago was the origin or complex eukarya |
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First microbial life |
In the 1950s, a grad student named Stanley Miller worked with his mentor, Harold Urey to simulate the "spark" that might have started forming organic molecules from primordial soup |
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Requirements of early life |
Genetic information storage
The ability to catalyze biochemical reactions
A way of separating the cell interior from the external environment |
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Ribozymes |
RNA molecules that catalyzes reaction
A combination of RNA and enzymes
It is a reaction catalyst
A genetic information storage that is catalytic and similar to DNA
Self-replicating for example |
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What is the splicing process? |
When there is a precursor rRNA. A portion of rRNA is excised but it needs restriction enzymes to splice and ligase to put together |
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Micelles |
When throwing a lipid into water, they assemble into micelles or into bilayers to protect the non-polar tails
May have been an early form of plasma membrane
May contain catalytic machinery |
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Who put together the three domain? |
Carl Woese |
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Double-stranded DNA |
Provides a backup copy of the genetic information
More stable than rRNA due to the change in the -OG group |
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Central Dogma |
DNA is transcribed into mRNA
mRNA is translated into proteins |
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What are other forms of RNA and why are they important? |
tRNA, rRNA and therefore showing the versatility of RNA molecules for life processes |
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Knowing the way the systems work allows us to examine microbial genomes from two different perspectives |
Examine the effects of single mutations in DNA individually (substition)
Studying and comparing pieces of genomes to each other across domains |
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Origin of Eukaryotes |
Endosymbiotic theory: a broken rule of phylogeny
Primitive prokaryotic microbes ingested other microbes, starting a symbiotic relationship, forming the first basic eukaryotes |
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How do microbes get energy? |
Heterotrophs: ingests preformed organic molecules
Autotrophs: produces organic molecules |
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Organic molecules are broken down by microbes for what? |
To harness chemical energy (ATP) through fermentation (lactate and ethanol) and aerobic respiration (CO2 + H2O AND 36 ATP)
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Cyanobacteria were the first to figure out what? |
Sunlight could break down water molecules to distribute electrons as water had an endless amount of electrons |
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Microbes and Diseases |
Diseases are catalyzed by one organisms
Microbes weren't always associated with diseases as they were believed to be caused by bad air or angry gods. When microbes were discovered, it was thought they could spontaneously form from nonliving matter |
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Contributions of Louis Pasteur |
Discovered that living organisms discriminate between optical isomers
Discovered the biological nature of alcoholic fermentation which is a microbially mediated process
Developed vaccines for anthrax, fowl cholera and rabies
Developed pasteurization and sanitation in hospitals
Disproved spontaneous generation and developed methods for controlling growth of microorganisms |
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How did Louis Pasteur disproved spontaneous generation theory |
He used the swan-neck flask - left it on the counter for month where air and dust accumulated. Once the flask was tilted, microbes replicated. Therefore it needs air and dust for contamination to occur |
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Robert Koch |
Determined Bacillus anthracis was the cause of anthrax and Myobacterium was the cause of tuberculosis |
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When can Koch's postulates be used? |
It can be used to show a specific microbe causes a specific disease |
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Koch's postulates: the steps |
The suspected microbe is identified. Take a diseased animal
A pure culture of the suspected microbe is obtained and streak it to form colonies
Experimental inoculation of the suspected microbe into a healthy test hosts causes the same illness
Suspected microbe recovered from experimentally inoculated host organism
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Koch's postulates in action: |
Gastric ulcers
Ulcers are sores on the lining of the stomach, though to be caused by excess acid
Researchers isolated the microbe Helicobacter pylori from ulcerated tissue
By applying the Koch's postulate rules, microbe was found to be the causative agent |
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Barrie Marshall obtaining the Nobel Prize |
Drank the pylori to test if it is the causative agent - cured by antibiotics - Won the Nobel PRize |
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What caused the transfer of the plague? |
Fleas and Rats.
Fleas bite rats and feed on their blood. Bacteria multiply in flea gut, which becomes clogged. Flea attempts to feed again
Flea bites rat, regurgitates bacteria into wound. New infection starts in rat bloodstream
Fleas bite human as alternative host. Flea regurgitates infected rat blood into wound. Bacteria multiplies causing disease and death |
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Diseases that have ravaged human populations |
Bubonic plague Small pox Spanish flue |
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Prevention of Infection |
Use of antiseptics Sanitation improvements Food/water safety Personal hygiene improvements Vaccinations Antibiotics
=Sanitation and knowledgge |
