Prokaryotic Internal Structure and Function

Question 1

Prokaryote v. Eukaryote Ribosome

Answer 1

Prokaryote (70S) v. Eukaryote (80S)

Question 2

Functions of the Plasma Membrane

Answer 2

• Selective permeability
• Anchor for enzymes
• Microbial energy generation (i.e. proton motive force)

Question 3

Membrane permeability

Answer 3

Permeable:

• Small hydrophobic molecules (gases, benzene)
• Small uncharged polar molecules (water, glycerol, ethanol)

Impermeable:

• Large uncharged polar molecules (amino acids, glucose, nucleotides)
• Ions

Question 4

Exoenzymes

Answer 4

• Enzymes made within the cell and then released outside to begin digestion
• Classified by type of molecule they hydrolyze

Question 5

Cytoplasm

Answer 5

~70% of cell weight

Question 6

Prokaryotic Ribosomes

Answer 6

• 23S and 5S combine with proteins to form 50S (large) subunit
• 16S combines with proteins to form 30S (small) subunit
• Together, the 50S and 30S combine to form a 70S ribosome

Question 7

Endospores

Answer 7

• Inactive, dehydrated bacterial cells in dormant stage
• Resistant to heat, UV, chemicals, and dehydration
• Stability comes from specific chemicals (dipicolinic acid) and proteins protecting DNA