Untitled Deck Flashcards
What does acellular mean in the context of viruses?
Viruses do not have cellular components, nor do they grow or metabolize organic materials. They consist of nucleic acid encased in protein and must use the cellular components of a living cell to reproduce.
What are prions?
Infectious agents composed primarily of protein that induce existing polypeptides in host cells to take on their form.
What are the main differences between prokaryotic and eukaryotic cells?
Bacteria and Archaea are prokaryotic cells, while algae, fungi, and protozoa have eukaryotic cells.
What is the function of the endoplasmic reticulum (ER)?
The ER is the passageway for the transport of materials within the cell and is involved in the synthesis of lipids and modification of newly formed polypeptide chains.
What is the role of the Golgi apparatus?
It performs the final modification of proteins and lipids and packs materials for secretion from the cell.
What do lysosomes contain?
Enzymes to digest ingested material or damaged tissue.
What is the function of centrioles?
They organize the spindle fibers during cell division.
What does Gram staining indicate?
Positive Gram staining results in purple/blue coloration, while acid-fast cells stain poorly and have mycolic acid in their walls.
What is binary fission?
A method of bacterial cell division where one cell divides into two identical cells, involving genome replication and cytoplasm separation.
What are the types of antibiotics and their functions?
Penicillins inhibit cell wall synthesis (gram-positive), tetracyclines inhibit protein synthesis (broad spectrum), beta-lactams inhibit cell wall synthesis (gram-positive), cephalosporins inhibit cell wall synthesis (gram-negative), and fluoroquinolones inhibit DNA replication (gram-negative).
What is the significance of photoautotrophic bacteria?
They make their own food like plants and release oxygen; examples include cyanobacteria.
What is the process of measuring bacterial growth using optical density?
It involves using a spectrophotometer to measure the turbidity of a bacterial culture.
What is the endosymbiotic theory?
It suggests that mitochondria and chloroplasts arose from prokaryotic cells establishing a symbiotic relationship within a eukaryotic host.
What are characteristics of Archaea?
They are prokaryotic, lack peptidoglycan in cell walls, are extremely tolerant to extreme conditions, and are involved in carbon and nitrogen cycles.
What are algal protists (algae)?
Eukaryotic organisms found in aquatic environments that can photosynthesize and produce oxygen.
What defines animal-like protists (protozoa)?
Eukaryotic organisms that hunt other microbes for food and mainly feed on bacteria.
What are fungi and their characteristics?
Eukaryotic organisms that cannot synthesize their own food, existing as single-celled yeasts or multicellular molds and mushrooms.
What are the components of viruses?
Viruses consist of nucleic acid (DNA or RNA) encased in protein and sometimes a membrane-like envelope.
What are viroids?
Small single-stranded circular RNAs that are infectious pathogens without a protein coating.
What is fermentation?
A metabolic process that converts sugars to acids, gases, or alcohol using microorganisms. Examples include bread making, wine production, and yogurt fermentation.
What is an operon?
A set of genes transcribed under the control of a single promoter, resulting in one long mRNA that contains coding sequences for multiple genes.
What is the trp operon?
A group of genes in E. coli that encode enzymes for tryptophan biosynthesis, regulated by the trp repressor.
What is the lac operon?
Contains genes for lactose metabolism, expressed when lactose is present and glucose is absent, regulated by the lac repressor and CAP.
