Cells: The Working Units of Life Part I: Prokaryotes

These flashcards cover important concepts related to cellular biology, especially focusing on prokaryotic cells, their structures, functions, and roles in biological systems.

What is cell theory?

Cell theory states that cells are the fundamental units of life, all organisms are composed of cells, all cells come from preexisting cells, and modern cells evolved from a common ancestor.

Why are cells small?

Cells are small to maintain a high surface-area-to-volume ratio which allows for efficient exchange of materials.

What is the role of the cell membrane?

The cell membrane acts as a selectively permeable barrier, maintaining a constant internal environment and facilitating communication.

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells lack membrane-enclosed organelles, while eukaryotic cells contain them.

What are ribosomes?

Ribosomes are the sites of protein synthesis in the cell.

What is peptidoglycan?

Peptidoglycan is a polymer of amino sugars that is a major component of the bacterial cell wall.

What is the function of flagella in bacteria?

Flagella allow bacteria to propel and move through their environment.

What is lateral gene transfer?

Lateral gene transfer is the process where genes from one species are incorporated into the genome of another species.

What are endospores?

Endospores are heat-resistant resting structures formed by some bacteria to survive harsh conditions.

How do bacterial pathogens typically infect a host?

Bacterial pathogens typically infect a host by arriving at the body surface, entering the body, evading defenses, multiplying, and then potentially infecting a new host.

What is the difference between endotoxins and exotoxins?

Endotoxins are released when certain Gram-negative bacteria are lysed and are rarely fatal, while exotoxins are soluble proteins produced by living bacteria and are often highly toxic.

What is quorum sensing?

Quorum sensing is a process by which bacteria communicate using chemical signals to coordinate behavior based on population density.

What are photoautotrophs?

Photoautotrophs are organisms that perform photosynthesis, using light as an energy source.

What do facultative anaerobes do?

Facultative anaerobes can shift their metabolism between aerobic and anaerobic modes depending on the availability of oxygen.

What is the significance of the Gram stain method?

The Gram stain method separates bacteria into Gram-positive and Gram-negative groups based on cell wall structure.