tedtih

What is microbiology?

Microbiology is the study of microorganisms, including bacteria, archaea, fungi, protozoa, algae, and viruses.

What is the difference between a prokaryotic and eukaryotic cell?

Prokaryotes do NOT have a nucleus or membrane-bound organelles. Eukaryotes DO have a nucleus and membrane-bound organelles.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

What structures do ALL cells have?

Plasma membrane, cytoplasm, DNA, and ribosomes.

What does the plasma membrane do?

It controls what enters and leaves the cell. Think of it like the cell’s security gate.

What is the main difference between bacterial DNA and eukaryotic DNA?

Bacterial DNA is generally in the nucleoid region rather than inside a nucleus. Eukaryotic DNA is inside a nucleus.

What are plasmids?

Small circular pieces of DNA found in bacteria that are separate from the main bacterial chromosome.

What are the four basic bacterial shapes?

Coccus = round; bacillus = rod-shaped; vibrio = curved/comma-shaped; spirillum = spiral-shaped.

What is peptidoglycan?

A major material in bacterial cell walls that provides strength and helps maintain cell shape.

What is the major difference between Gram-positive and Gram-negative bacteria?

Gram-positive bacteria have a thick peptidoglycan cell wall. Gram-negative bacteria have a thinner peptidoglycan layer plus an outer membrane.

Why do Gram-positive and Gram-negative bacteria stain differently?

Their cell wall structures are different, causing them to react differently during the Gram stain.

What are flagella used for?

Movement. Think: flagella = “feet” or propellers.

What are fimbriae mainly used for?

Attaching bacteria to surfaces or host cells.

What are pili used for?

They can help bacteria attach and can also be involved in transferring DNA between bacteria.

What are axial filaments?

Structures used for movement in certain spiral-shaped bacteria. They allow the bacteria to move in a twisting/corkscrew motion.

What is a glycocalyx?

A sticky substance surrounding some bacterial cells that can help with attachment and protection.

What is a capsule?

A well-organized glycocalyx that is firmly attached to the bacterial cell.

What is an endospore?

A highly resistant structure formed by certain bacteria that allows them to survive harsh conditions.

What is sporulation?

The process by which certain bacteria form an endospore.

What are the major organelles you should know in eukaryotic cells?

Nucleus = DNA; mitochondria = ATP/energy; ribosomes = proteins; ER = makes/processes materials; Golgi = modifies/packages; lysosomes = digestion; chloroplasts = photosynthesis in plants/algae.

What does the nucleus do?

Stores the cell’s DNA and controls many cell activities.

What do mitochondria do?

Produce ATP, which provides usable energy for the cell.

What do ribosomes do?

Make proteins.

What does the endoplasmic reticulum (ER) do?

It is involved in making and transporting materials. Rough ER has ribosomes and is involved in protein production.

What does the Golgi apparatus do?

Modifies, sorts, and packages materials for transport.

What is the endosymbiotic theory?

The theory that mitochondria and chloroplasts originated from bacteria that were engulfed by an ancestral eukaryotic cell and eventually became permanent parts of the cell.

What is a biofilm?

A community of microorganisms attached to a surface and surrounded by a protective substance they produce.

What is a pathogen?

A microorganism or agent capable of causing disease.

What is the microbiome?

The community of microorganisms associated with a particular environment, including the human body.

What is spontaneous generation?

The old idea that living organisms could arise from nonliving matter.

What is biogenesis?

The idea that living organisms come from other living organisms.

What did Francesco Redi’s experiment help disprove?

The idea of spontaneous generation, specifically that maggots came directly from rotting meat.

What did Louis Pasteur’s experiment demonstrate?

Pasteur showed that microorganisms came from existing microorganisms in the environment, supporting biogenesis and helping disprove spontaneous generation.

What is fermentation?

A process involving microorganisms that can produce useful products such as alcohol and acids. It was important in Pasteur’s work.

What is pasteurization?

A process of heating a substance to reduce harmful microorganisms and slow spoilage without completely sterilizing it.

What is germ theory?

The idea that microorganisms can cause disease.

What were Koch’s postulates used for?

They provided a method for determining whether a particular microorganism causes a particular disease.

What did Edward Jenner contribute to microbiology?

He developed an early successful vaccination approach using cowpox to protect against smallpox, helping establish vaccination.

What did Alexander Fleming discover?

Penicillin, an antibiotic produced by a mold that could inhibit bacterial growth.

What is the “big picture” of microbiology history?

Scientists gradually moved from believing in spontaneous generation toward biogenesis and germ theory, eventually developing methods to identify disease-causing microbes, prevent disease through vaccination, and treat infections with antimicrobial drugs.