Microbiology Flashcards
Definition of Microorganism (Microbe)
Organisms to small to be seen by the naked eye.
Definition of Microbiologist
A scientist who studies microbiology
Definition of Microbiology
Study of Micro-organisms
Definition of SI unit
Standard units of measurement defined by the International System of Units
What is the smallest micro-organisms?
Viruses
20 - 100nm
What is the largest micro-organisms? And size?
Protista and Fungi
10um - 100um
Bacteria size
1um - 5um
Definition of Binary Fission
Asexual reproduction of a single cell in which it divides by mitosis
Definition of Unicellular
An organism consisting of only one cell
Definition of Multicellular
An organism made up of many cells
Definition of Nucleus
An organelle present in eukaryotic cells, contains genetic material
Definition of Organelles
A sub-cellular structure that has a specific job to perform in a cell
Definition of Phylogenetic tree
A diagram that depicts the line of evolutionary descent of organisms.
Acellular
Non-cellular
Prokaryotes Characteristics
- No true nucleus
- DNA is not enclosed by a nuclear membrane
- Cell division through binary fission
- Absent membrane bound organelles
- 2 main groups: Bacteria & Archae Bacteria
Eukaryotes Characteristics
- True nucleus
- DNA is enclosed by nuclear membrane
- Cell division by mitosis
- Membrane bound organelles in cytoplasm
- 4 Kingdoms: Plant, Animal, Fungi, Protista
What are the characteristics of life?
(MRS GREN)
Movement Respiration Response to stimuli Growth Reproduction Excretion Nutrition
Definition of Host
An organism that harbours a parasite.
Definition of Nucleoid
Region within the cell of a prokaryote
Definition of Pathogen
A microorganism that causes diseases
What does obligate intracellular parasites mean?
They cannot multiply without infecting living cells/hosts
Definition of Capsid
The protein coat surrounding the nucleic material of a virus.
Definition of Bacteriophage
A virus that infects bacteria.
Definition of Envelope (virus)
A bubble of lipid surrounding a virus, from the previous host’s cell membrane.
Characteristics of a Virus
- Obligate intracellular parasites
- Host specific
- Pathogens
- Not considered living, they only reproduce in a living host cell
- If a virus cannot find a host, becomes dormant
Structure of a Virus
- Acellular
- Virus surrounded by a bubble of lipid (envelope)
- Core of nucleic acid enclosed by a protein coat (capsid)
Shapes of Viruses
- Rod-shaped
- Spherical
- Complex/phage (bacteriophage)
Examples of Viruses
- HIV/AIDS
- Herpes
- Influenza
- Covid-19
- Chickenpox
Definition of Autotrophic
Organisms that synthesize its own food
Definition of Heterotrophic
Organism that sources their food from its environment
Definition of Saprotrophic
Organisms that feed on dead organic matter
Definition of Flagella
Whip-like protruding filaments help cell/organism move
singular - flagellum
Characteristics of Bacteria
- Kingdom: Monera
- Majority heterotrophs
- Feeding forms:
- Heterotrophs (parasitic/mutualistic)
- Saprotrophic
- Autotrophic (photosynthesis/chemosynthesis)
- Asexual reproduction: binary fission
Structure of Bacteria
- Unicellular, join together in filaments/colonies
- Have cell wall, cell membrane, cytoplasm with ribosomes, circular DNA strands
- No organelles & nucleus
- Prokaryote
- Some have flagella (to move in liquid)
Shapes of Bacteria
- Rod-shaped (s: Bacillus, p: Bacilli)
- Spherical/round (s: Coccus, p: Cocci)
- Spiral-shaped (s: Spirillum, p: Spirilla)
- Comma-shaped (s: Vibrio, p: Vibrios)
