Prokaryotic cell structure and Endosymbitoic Theory

What are the basic characteristics of prokaryotic cells?

Generally smaller than eukaryotic cells, higher surface area to volume ratio, lack membrane-bound organelles, some have two membranes surrounding the cytoplasm.

What structures are shared by all cells?

Plasma membrane, DNA, cytoplasm, ribosomes.

What is the composition of the bacterial cell wall?

Made of peptidoglycan.

What type of ribosomes do prokaryotes contain?

Smaller ribosomes (70S).

What type of ribosomes do eukaryotes contain?

Larger ribosomes (80S).

What is the structure of prokaryotic DNA?

Naked circular loop of DNA located in the cytoplasm within the nucleoid region.

How does prokaryotic DNA differ from eukaryotic DNA?

Prokaryotic DNA is circular and not associated with proteins; eukaryotic DNA is linear and associated with histone proteins.

What are the two types of genetic material in prokaryotes?

Large single loop chromosome and plasmids.

What is binary fission?

Asexual reproduction used by prokaryotes where a single celled organism splits into two identical daughter cells

Why do prokaryotes not undergo mitosis?

They lack a nucleus and have a single chromosome.

What is the function of the slime capsule in prokaryotes?

It serves as an outer protective layer and helps bacteria adhere to surfaces or other cells.

What is the function of the flagellum in prokaryotes?

Used for movement/locomotion.

What are pili?

Hair-like structures on the surface of prokaryotic cells.

What is symbiosis?

Interaction between two species where both benefit from the relationship.

What is endosymbiosis?

A biological partnership where one organism lives inside the body or cells of another organism.

What occurred in Step 1 of the endosymbiotic theory?

Infoldings in the plasma membrane of a proto-eukaryote gave rise to endomembrane components.

What happened in the first symbiotic event of the endosymbiotic theory?

The host cell ingested aerobic bacteria, which evolved into mitochondria.

What happened in the second symbiotic event of the endosymbiotic theory?

The host cell consumed photosynthetic bacteria, which evolved into chloroplasts.

What mutual benefits existed in early endosymbiosis for animal cell ancestors?

Large prokaryote provided shelter and nutrients; smaller prokaryote provided energy in the form of ATP.

What mutual benefits existed in early endosymbiosis for plant cell ancestors?

Large prokaryote provided carbon dioxide; smaller prokaryote provided oxygen and organic molecules.

What key evidence supports the endosymbiotic theory?

Mitochondria and chloroplasts share features with prokaryotes: similar size, contain their own circular DNA, and have smaller ribosomes (70S).