Lecture 1 - Microbiology Introduction Flashcards
What is microbiology?
The study of microorganisms including unicellular, multicellular and acellular organisms. It includes the study of bacteria, viruses, fungi, and parasites
What factors are responsible for shifting the causes of death from infectious to non-microbial?
- The improvement in sanitation. 2. Introduction of vaccination programs. 3. Introduction of anti-microbial agents
How is microbiology relevant in agriculture?
- Bacteria can form nodules on legume roots. They then metabolize atmospheric nitrogen gas and sulfur into compounds that improve soil fertility.
- Bacteria in ruminants help break down cellulose for energy. Glucose from cellulose is broken down by microorganisms and then goes through microbial fermentation to extract nutrition such as fatty acids.
How is microbiology relevant in human nutrition?
- The human gut microbiome helps to break down complex carbohydrates.
- It also helps to synthesize vitamin K and biotin
How is microbiology relevant in food?
- Microbiology is involved in food spoilage.
- Involved in food preparations (i.e.; fermentation).
- Yeast for carbon dioxide formation for rising (bread)
How is microbiology relevant in industries?
- Bacteria used to convert high glucose containing plants into ethyl alcohol for fuel.
(Cellulose from grass or cornstarch from corn can be broken down into glucose and then fermented into ethanol for gas.)
What are microorganisms?
They are living things that can be too small to be seen by the unaided eye but some organisms within microbiology can be seen unaided.
Where do microorganisms live?
They live in every environment on Earth that supports life.
What is central to the study of microbiology?
- Cultivation of microorganisms.
2. Microscopic visualization of microorganisms (to identify what the microorganism is)
Define culture
A collection of microbial cells grown using a nutrient medium
Define medium
A liquid or solid nutrient mixture used to culture microorganisms
Define growth
Increase in number of cells with time
Define colony
Macroscopically visible population of cells growing on a solid medium(arising from a single cell)
What are some things cells have in common?
Cytoplasmic membrane (permeability barrier), cytoplasm (fluid portion of the cell), various macromolecules (proteins, lipids, carbohydrates), ribosomes (structures responsible for protein synthesis), cell wall (plant cells and most microorganisms)
Compare and contrast eukaryotic cells and prokaryotic cells
The chromosome of prokaryotic cells are usually single and circular. Prokaryotic cells have a nucleus with no nuclear envelope or nucleoli. Prokaryotic cells do not have membrane-bound organelles. Prokaryotic cells usually have a cell wall that usually contains peptidoglycan. The plasma membrane of prokaryotic cells have no carbohydrates and most lack sterols. Prokaryotic cells have ribosomes called the 70S made of a 50 large and 30 small Sped-burg subunit. Prokaryotic cells tend to be 0.2-2 micrometers in diameter.
Eukaryotic cells have multiple chromosomes. The nucleus is membrane-bound with nucleoli present. Eukaryotic cells have membrane-bound organelles. A cell wall is only present in plant cells with no peptidoglycan. The plasma membrane have sterols and carbohydrates. The ribosome in eukaryotic cells is more dense with about 80S (broken down into 60 large and 40 small Sped-burg subunits). Tends to be 10-100 micrometers in diameter.
