Define microbiology.
Key Terms
Bacterias are members of what kingdom? Yeasts and molds?
Bacteria: Monera
Yeasts + molds: Fungi
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
Define microbiology. | the study of living organisms too small to be seen by the unaided human eye |
Define microorganisms. | Organisms that are only visible through a microscope |
What are the characteristics of microorganisms? | They multiply rapidly, and transfer easily from one surface to another (cross- contamination) |
What is cross-contamination? | transfer easily from one surface to another (cross- contamination) |
What are the microorganisms that have positive use in foods? | bacteria, yeasts, and molds |
Bacterias are members of what kingdom? Yeasts and molds? | Bacteria: Monera Yeasts + molds: Fungi |
What do microorganisms depend on to grow and multiply? | Outside sources |
Are bacteria single-celled or multiple-celled? | single-celled organisms |
How does bacteria multiply? | Cell division |
Describe the cells of bacteria? | Their cells have no nucleus and are filled with a gelatinous liquid called cytoplasm |
How long is bacteria? | 3 micrometers long |
How is bacteria classified? | by shape, cell wall structure, and oxygen needs |
Name the 3 basic shapes of bacteria. | – Bacilli have a rod shape |
Name the 2 types of cell wall structures of bacteria. |
- Gram-negative turn red |
How are the cell wall structures of bacteria identified? | by the ability to be stained by a crystal violet dye, called Gram’s stain |
Name the 3 categories of bacteria based on oxygen needs. | Aerobic bacteria must have oxygen to function |
What kind of bacteria spoils cabbage? What prevents the aerobic bacteria to grow? |
|
Aerobic bacteria in cabbage can multiply and develop what? | the flavor and texture of sauerkraut |
What do bacterial growth rates depend on? | pH, air, temperature, and nutrients |
Define fungus. | a plant that lacks chlorophyll |
Are fungi single-celled? Do they have a nucleus? | – are not always single-celled |
What is the function of fungus in nature? | widely distributed in nature and help organic matter decay |
Give examples of fungus. | mushrooms, molds, mildew, rust, and yeast |
How is fungi classified? | by their structure and reproduction methods |
The basic structure of fungi is made of what? | made of filaments or tubes called hyphae |
Describe the structure of hyphae. | have elongated cells or chains of cells that absorb nutrients from the environment |
How is myecelium formed? | Hyphae intertwines and forms a branched network |
How does myecelium reproduce? | by creating spores |
Define spores. | the reproductive cells of fungi |
How do spores develop? | in a sac- or balloon-like structure that explodes when full |
How big are spores? What are they resistant to? | Spores are microscopic and resistant to harsh environments |
Define molds. | fungi that form a mycelium structure with a fuzzy appearance |
What do molds produce? What do they do? | Many produce antibiotics that kill bacteria likely to be growing in the same area |
Define yeasts. | fungi with a single-celled structure |
What do yeasts produce? | produce alcohol and carbon dioxide |
What do yeasts form on soil or plants? What do they form in animals? | Soil or plants: mycelium structures |
Name 4 common characteristics of microorganisms. | – grow rapidly and are good sources of edible |
Define a pure culture. | a large volume of one type of microbe grown purposely |
What are microorganisms used for in food processing plants? | development of such foods as pickles, cheese, and beverages |
Define starter cultures. | pure cultures of microorganisms that are added to foods to begin a fermentation |
Define microbial enzymes. | Enzymes produced by microorganisms |
What is the source of most changes in food products? | Microbial enzymes |
How do microbial enzymes act in the body? | – Microorganisms excrete digestive enzymes to break down large macromolecules for transport through the microbial cell wall |
How can microorganisms be classified | by the organic molecules they use as a food source |
What are proteolytic microorganisms? | release proteases that change proteins into amino acids and are used to clot milk, tenderize meat, and remove pulp from cacao beans |
What are lipolytic microorganisms? | produce enzymes that digest fats and are used to flavor cheese, remove egg yolk, and clean up oil spills |
How are microorganisms classified in terms of their scientific names? | By 2 Latin names
|
What are characteristics of the genus name? | – is always capitalized | – indicates a family of organisms that have similar characteristics |
What are characteristics of the species name? | – is never capitalized | – identifies the type of microbe within the family |
Name the 4 factors that affect microbe growth. |
|