CH 3 Prokaryotes vs Eukaryotes

Bacterial cytoplasmic membrane components?

Phospholipids and Proteins

Prokaryotes Plasma Membrane

Phospholipid bilayer, site of ATP production

Eukaryotes Plasma Membrane

Phospholipid bilayer (atp prod. occurs in mitochondria instead)

Prokaryotes Cell wall

Usually present (bacteria and archaea). Provides shape and protection from osmotic pressure.

Eukaryotes Cell Wall

Present in plants, fungi, and algae; absent in animal cells. Composition varies by organism.

Prokaryotes Chromosome Shape

one circular chromosome located in the nucleoid.

Eukaryotes Chromosome Shape

Multiple linear chromosomes inside the nucleus.

Prokaryotes DNA

DNA is located in the nucleoid region (no membrane surrounds it).

• NO NUCLEUS

Eukaryotes DNA

DNA is enclosed within a membrane-bound nucleus.

Prokaryotes Histone Proteins

Absent in bacteria (archaea have histone-like proteins).

Eukaryotes Histone Protein

Present. DNA is wrapped around histone proteins to form chromatin.

Prokaryotes Peptidoglycan

Present only in bacteria. Gram-positive bacteria have thick peptidoglycan; Gram-negative bacteria have thin peptidoglycan. Archaea do not have peptidoglycan.

Eukaryotes Peptidoglycan

None

• Plant cell walls contain cellulose; fungal cell walls contain chitin.

Prokaryotes Flagella

Simple structure made of flagellin; rotates like a propeller.

• filament, the hook, and the basal body

Eukaryotes Flagella

Inside of cell, composed of tubulin/microtubules

• undulate

• NO hook

Prokaryotes Ribosomes

70S ribosomes (30S + 50S subunits).

Eukaryotic Ribosomes

80S ribosomes (40S + 60S subunits) in the cytoplasm. Mitochondria and chloroplasts contain 70S ribosomes.

Prokaryotic Pili

Present. Used for attachment and DNA transfer (conjugation).

Eukaryotic Pili

Absent

Prokaryotic Capsule

May be present in some bacteria as a well-organized glycocalyx. Protects against phagocytosis, prevents dehydration, and aids attachment.

Prokaryotic Slime Layer

May be present in some bacteria as a loose glycocalyx. Helps cells adhere to surfaces and form biofilms.