Microbiology: Cell Structure and Function Flashcards
7 cards from real AP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Microbiology: Cell Structure and Function flashcards as text
Mycoplasmas are bacteria that can survive without a cell wall. What structural adaptation compensates for the lack of a wall to maintain cell integrity?
Answer: Sterols incorporated into the cytoplasmic membrane
Mycoplasmas incorporate sterols (obtained from their host) into their cytoplasmic membrane, increasing its rigidity and stability in the absence of a cell wall.
A researcher uses lysozyme to disrupt bacterial cell walls. In a hypertonic solution, gram-positive bacteria treated with lysozyme would become:
Answer: Protoplasts that remain intact due to osmotic support
In a hypertonic (high-solute) solution, the osmotic pressure is balanced so water does not rush into the cell; gram-positive cells stripped of their wall become protoplasts that remain intact.
Which of the following accurately describes how archaea differ from bacteria in membrane composition?
Answer: Archaea have ether-linked isoprenoid chains; bacteria have ester-linked fatty acids
Archaeal membranes are composed of isoprenoid side chains linked to glycerol via ether bonds, whereas bacterial membranes use fatty acids linked via ester bonds.
Gas vesicles are found in some aquatic microorganisms. What is their primary function?
Answer: Buoyancy regulation to control vertical position in water columns
Gas vesicles are hollow protein-shelled structures filled with gas that provide buoyancy, allowing microorganisms like cyanobacteria to adjust their depth in aquatic environments.
The 70S ribosome of bacteria is composed of which two subunits?
Answer: 30S and 50S
Bacterial (70S) ribosomes are composed of a small 30S subunit (containing 16S rRNA) and a large 50S subunit (containing 23S and 5S rRNA).
Polyphosphate granules (volutin granules) found in some bacteria serve as a reserve of which resource?
Answer: Phosphate and energy
Polyphosphate (volutin) granules store inorganic phosphate chains that can be used as an energy source and as a phosphate reservoir for biosynthesis.
Which of the following correctly explains why the bacterial cytoplasmic membrane must be selectively permeable?
Answer: It must maintain concentration gradients essential for ATP synthesis and regulate transport of nutrients and waste
Selective permeability allows the membrane to maintain electrochemical gradients needed for ATP synthesis while controlling which nutrients enter and which waste products exit the cell.