Intro to Microbiology & Microbes

Flashcards covering introductory microbiology, prokaryotic and eukaryotic microbes, and viruses based on the lecture notes.

Microbe

A cellular or acellular organism, encompassing prokaryotic, eukaryotic, unicellular, or multicellular forms.

Bacteria

Prokaryotic, unicellular microbes, examples include E. coli and Streptococcus.

Archaea

Prokaryotic, unicellular microbes, examples include Methanogens and Halophiles.

Fungi

Eukaryotic, unicellular or multicellular microbes, examples include Yeast and Mold.

Protozoa

Eukaryotic, unicellular microbes, examples include Amoeba and Paramecium.

Algae

Eukaryotic, unicellular or multicellular microbes, examples include Green algae and Diatoms.

Helminths

Eukaryotic, multicellular microbes, examples include Tapeworms and Roundworms.

Viruses

Acellular microbes, examples include Influenza and HIV.

Prions

Acellular microbes, responsible for diseases like Mad cow disease.

Free-living

A microbial lifestyle where organisms live independently.

Symbiotic

A microbial lifestyle involving close interactions, including mutualism, commensalism, and parasitism.

Parasitic

A microbial lifestyle where one organism benefits at the expense of another.

Microbial Taxonomy

The classification system for microbes: Domain
D Kingdom
D Phylum
D Class
D Order
D Family
D Genus
D Species.

Cocci

Spherical-shaped prokaryotic cells.

Bacilli

Rod-shaped prokaryotic cells.

Spirilla/Spirochetes

Spiral-shaped prokaryotic cells.

Strepto-

A prokaryotic cell arrangement indicating chains.

Staphylo-

A prokaryotic cell arrangement indicating clusters.

Diplo-

A prokaryotic cell arrangement indicating pairs.

Peptidoglycan

A polymer forming the cell wall of bacteria; thick in Gram-positive, thin in Gram-negative.

Teichoic acids

Present in Gram-positive cell walls, providing structural stability and adhesion.

Outer membrane

A barrier to antibiotics found outside the peptidoglycan layer in Gram-negative bacteria, containing LPS.

Periplasmic space

The space located between the cytoplasmic membrane and the outer membrane in Gram-negative bacteria, containing enzymes and involved in transport.

Mycolic acid

A waxy substance found in the cell walls of Mycobacteria, contributing to their acid-fast property.

Gram Stain Procedure

A differential staining technique involving crystal violet, iodine (mordant), alcohol (decolorizer), and safranin (counterstain) to classify bacteria.

Gram-positive bacteria

Bacteria that stain purple in the Gram stain due to their thick peptidoglycan layer.

Gram-negative bacteria

Bacteria that stain pink in the Gram stain due to their thin peptidoglycan layer and outer membrane.

Flagella

External structures providing motility to bacteria through 'runs & tumbles'.

Fimbriae

Short, hair-like external structures involved in bacterial adhesion.

Pili

External structures, specialized sex pili are used for DNA transfer during conjugation.

Glycocalyx

An external polysaccharide layer; can be a loose slime layer for dehydration protection and adherence, or a dense capsule for protection against phagocytosis.

Biofilms

Communities of microbes attached to surfaces and encased in Extracellular Polymeric Substance (EPS).

Chromosome (prokaryotic)

The single, circular genetic information found in the cytoplasm of prokaryotes.

Plasmids

Extra-chromosomal DNA often carrying antibiotic resistance genes in prokaryotes.

Ribosomes

Internal structures responsible for protein synthesis in both prokaryotic and eukaryotic cells.

Endospores

Dormant, resistant structures formed by some bacteria (e.g., Bacillus, Clostridium) for survival under harsh conditions through sporulation and germination.

Nucleus (eukaryotic)

An organelle in eukaryotic cells that stores DNA.

Endoplasmic Reticulum (ER)

A network of membranes in eukaryotic cells involved in protein and lipid synthesis.

Golgi apparatus

An organelle in eukaryotic cells responsible for protein processing and secretion.

Mitochondria

Organelles in eukaryotic cells responsible for ATP production.

Cytoskeleton

A network of protein filaments in eukaryotic cells providing structural support and aiding in transport.

Yeast

Unicellular fungi that can form pseudohyphae.

Mold

Multicellular fungi consisting of hyphae (vegetative vs. reproductive) and reproducing via spores.

Mycotoxins

Toxic substances produced by fungi, contributing to their medical importance.

Trophozoite

The active, feeding stage of a protozoan.

Cyst

The dormant, resistant stage of a protozoan.

Obligate intracellular parasites

Viruses are this type of parasite, meaning they must live and reproduce inside other cells.

Capsid

The protein coat of a virus, made of capsomers, that protects the nucleic acid and determines viral shape (icosahedral, helical, complex).

Envelope (viral)

A lipid bilayer derived from the host cell membrane that surrounds some viral capsids and may contain spikes for attachment.

Spikes/Tail fibers

Viral proteins used for attachment to host cells; spikes for animal viruses, tail fibers for bacteriophages.

Viral Nucleic Acid

Can be DNA or RNA, and may carry viral enzymes like reverse transcriptase.

Adsorption (viral)

The first step in animal virus replication, involving attachment to the host cell.

Penetration (viral)

The second step in animal virus replication, where the virus enters the host cell.

Uncoating (viral)

The third step in animal virus replication, involving the release of the viral genome from the capsid.

Synthesis (viral)

The fourth step in animal virus replication, involving the replication of viral nucleic acids and proteins.

Assembly (viral)

The fifth step in animal virus replication, where new virions are formed.

Release (viral)

The final step in animal virus replication, where new virions exit the host cell, either by budding or lysis.

Persistent Viruses

Viruses that remain in host cells as proviruses, which can lead to latent infections or cancer (e.g., herpes).

Proviruses

Viral DNA integrated into the host cell's genome, characteristic of persistent viral infections.

Bacteriophages

Viruses that infect bacteria.

Lytic cycle

A bacteriophage replication cycle involving infection, replication, and lysis of the host cell.

Lysogenic cycle

A bacteriophage replication cycle where the viral genome integrates into the host genome as a prophage and can later enter the lytic cycle.

Prophage

The integrated bacteriophage DNA within the host bacterial genome during a lysogenic cycle.

Lysogenic conversion

Changes in the host bacterium's phenotype due to the presence of a prophage.