Microbiology 1 Flashcards
What is food?
Food is material of plant or animal origin that contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or minerals, ingested for energy, growth, and life maintenance.
What are the three main types of microorganisms in food microbiology?
Pathogenic microorganisms (cause illness), spoilage microorganisms (cause food waste), and beneficial microorganisms (used in food production).
Who coined the term ‘Microbial World’?
Professor Roger Stanier (University of California, Berkeley) in 1966.
What are the three domains of life?
Prokaryotes (Bacteria), Eukaryotes, and Archaea.
Who discovered the third domain of life (Archaea)?
Carl Woese in 1977.
What are the five main groups of microorganisms?
Algae, Protozoa, Bacteria, Fungi, and Viruses.
What are the main bacterial shapes?
Rod (bacilli), coccoid (cocci), and pleomorphic (variable shapes).
What is the difference between Gram-positive and Gram-negative bacteria?
Gram-positive have a thick peptidoglycan layer, while Gram-negative have a thin layer and an outer LPS membrane (toxic to humans).
What is binary fission?
A method of bacterial reproduction where a single cell divides into two identical daughter cells.
What are bacterial spores and why are they important?
Dormant, highly resistant structures that allow bacteria to survive unfavorable conditions and can spread via dust and air.
What are extremophiles?
Microorganisms (mainly archaea) that thrive in extreme environments such as high salinity, high temperature, and acidity.
What are key characteristics of fungi?
Eukaryotic, include yeasts and molds, reproduce via spores, and decompose organic matter.
What is the role of yeast in food production?
Yeasts ferment carbohydrates to produce ethanol and CO₂, used in bread, beer, and wine production.
What is the difference between bacterial spores and fungal spores?
Bacterial spores are for survival, highly resistant; fungal spores are for reproduction and dispersion.
What are viruses composed of?
Viruses consist of genetic material (DNA or RNA) enclosed in a protein coat, sometimes with a lipid membrane.
How do viruses reproduce?
Viruses require a host cell to replicate, as they lack cellular structures for independent reproduction.
What is the role of microorganisms in food?
Microorganisms contribute to food production (fermentation), spoilage, and can cause disease.
