A Survey of Prokaryotic Cells and Microorganisms

These flashcards cover the major concepts discussed in the lecture about prokaryotic cells and microorganisms.

What are the basic characteristics of all living things?

All living things are made of cells that share common characteristics: basic shape, internal content, DNA chromosomes, ribosomes, and metabolic capabilities.

What are the two basic types of cells?

Prokaryotes and Eukaryotes.

What types of organisms are prokaryotes?

Bacteria and archaea.

What distinguishes eukaryotes from prokaryotes?

Eukaryotes have a membrane-surrounded nucleus and membrane-bound organelles.

What are the characteristics of life?

Heredity and DNA, reproduction, metabolism and enzymes, cellular organization, transport, growth and development, responsiveness.

What is the function of the cell envelope in bacteria?

It is an external covering that maintains cell integrity.

What is the structure of the cytoplasmic membrane in bacteria?

It is a bilayer of lipids with attached proteins and is involved in transport, synthesis, and energy reactions.

What are phospholipids made of?

They consist of glycerol, two fatty acids, and a phosphate group.

What are the two types of bacterial cell walls?

Gram-positive and Gram-negative cell walls.

What is the Gram stain method used for?

To distinguish between Gram-positive and Gram-negative bacteria.

What is the primary component of the bacterial cell wall?

Peptidoglycan.

Describe the Gram-positive cell wall.

It has a thick layer of peptidoglycan and may include teichoic and lipoteichoic acids.

Describe a Gram-negative cell wall.

It has a thin peptidoglycan layer, an outer membrane, and lipopolysaccharides.

What are endospores?

Inert, resting cells produced by certain bacteria that can survive extreme conditions.

What is the main function of flagella in bacteria?

They provide motility and help bacteria move towards stimuli (chemotaxis and phototaxis).

What are fimbriae?

Fine, hairlike appendages that help in the adhesion to surfaces.

What differentiates pili from fimbriae?

Pili are specialized structures for DNA transfer (conjugation), while fimbriae aid in adhesion.

What does glycocalyx refer to?

A coating of sugars and/or proteins external to the bacterial cell wall that can be a slime layer or a capsule.

What are the functions of glycocalyx?

Protection from dehydration, inhibition of phagocytosis, and attachment to surfaces.

What is the nucleoid in bacteria?

An area where the bacterial DNA is aggregated; it is not a true nucleus.

What are plasmids?

Free small circular DNA molecules that are not essential for bacterial growth.

Describe the structure and function of bacterial ribosomes.

They are the site of protein synthesis, made of rRNA and proteins, and differ from eukaryotic ribosomes in size.

What is the significance of bacterial inclusions?

They serve as intracellular storage bodies for nutrients the bacteria can use when environmental sources are depleted.

What are the three basic shapes of bacteria?

Coccus (spherical), bacillus (rod), and spiral.

What does pleomorphism refer to in bacteria?

Variation in cell shape and size within a single species.

What are the two major domains of prokaryotes?

Bacteria and Archaea.

What are the unique features of Archaea?

They have distinct genetic sequences in rRNA, different metabolic pathways, and can thrive in extreme environments.

What type of bacteria are cyanobacteria?

Photosynthetic, gram-negative bacteria that provide oxygen to the environment.

What is the primary use of Bergey's Manual in microbiology?

It is a resource for classifying and identifying prokaryotes based on genetic and phenotypic information.

What is the significance of the G+C base composition in bacterial classification?

It can indicate relatedness among bacteria; significant differences in G+C percentage suggest genetic distance.

What are some medically important Gram-negative bacteria?

Neisseria (gonorrhea), Pseudomonas (pneumonia), and Escherichia (E. coli).

What are obligate intracellular parasites?

Bacteria like Rickettsia and Chlamydia that cannot multiply outside of a host cell.