Prokaryotic and Eukaryotic Cells Lecture Review

A series of flashcards based on key concepts from lecture notes on prokaryotic and eukaryotic cells, focusing on characteristics, structure/function, and related processes.

What are the distinguishing characteristics of prokaryotic cells compared to eukaryotic cells?

Prokaryotic cells are generally smaller, lack a nucleus, have circular DNA, and lack membrane-bound organelles, while eukaryotic cells are larger, have a nucleus, linear DNA, and membrane-bound organelles.

Which structure is present in bacterial cells but absent in animal cells?

Cell wall.

What are the three basic shapes of bacterial cells?

Bacillus (rod-shaped), Coccus (spherical), Spiral (vibrio, Spirillum, Spirochete).

What is the composition of peptidoglycan?

Peptidoglycan is a polymer of disaccharides consisting of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), linked together by polypeptides.

What key element differentiates Gram-positive and Gram-negative cells in the Gram staining procedure?

Gram-positive cells have a thick peptidoglycan layer and no outer membrane, while Gram-negative cells have a thin peptidoglycan layer and an outer membrane.

Why is penicillin not effective against all bacterial infections?

Penicillin targets bacteria with a thick peptidoglycan cell wall, which is more prevalent in Gram-positive bacteria; Gram-negative bacteria have a thinner peptidoglycan layer and are less affected.

What is the function of the plasma membrane in bacterial cells?

The plasma membrane regulates the passage of specific molecules and substances through its selective permeability.

What differentiates fimbriae from pili in bacteria?

Fimbriae are numerous hair-like structures used for adhesion, while pili have a similar function but are also involved in transferring DNA between cells.

What is the endosymbiotic theory?

The endosymbiotic theory suggests that eukaryotic cells evolved when larger prokaryotic cells absorbed smaller bacterial cells, leading to a mutually beneficial relationship that resulted in the development of organelles.

Which two bacterial genera are known to form endospores?

Bacillus and Clostridium.

What is one reason why Gram-negative bacteria would appear purple if the order of crystal violet and safranin was switched?

If the order of the dyes is switched, Gram-negative bacteria would retain the purple dye, becoming indistinguishable from Gram-positive bacteria.