뒤로Prokaryotic Cell Structure and Function Micro L 4
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이 집합의 용어 (25)
The main shapes are cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped).
It maintains cell shape, provides structural support, and protects against osmotic pressure changes.
Peptidoglycan is a polymer of sugars and peptides forming the bacterial cell wall, providing rigidity and shape.
Gram-positive walls have a thick peptidoglycan layer with teichoic acids; gram-negative walls have a thin peptidoglycan layer between two membranes with lipopolysaccharide (LPS).
It controls substance passage, allowing nutrient uptake and waste removal, and maintains concentration and electrical gradients.
Movement of small, uncharged molecules directly through the membrane without energy use.
Passive transport of larger or charged molecules across the membrane via protein carriers or channels, without energy use.
Active transport moves substances against their concentration gradient using energy (ATP), while passive transport relies on gradients and requires no energy.
A special active transport where nutrients are chemically modified during transport to trap them inside the cell.
Fimbriae are bristle-like projections used for adherence to surfaces and other cells.
Pili are specialized fimbriae that transfer DNA between cells during conjugation.
Flagella rotate to propel bacteria through their environment, enabling movement toward or away from stimuli (taxis).
A metabolically inert, resistant structure formed by some gram-positive bacteria to survive extreme conditions.
The region containing the single, circular chromosome of DNA in prokaryotes.
Small, circular DNA molecules separate from the chromosome that can carry additional genes.
Osmosis is water movement across a semipermeable membrane from low to high solute concentration, affecting cell volume and pressure.
Isotonic: no net water movement; hypertonic: water leaves cell causing shrinkage; hypotonic: water enters cell causing swelling but cell wall prevents bursting.
A sticky polysaccharide layer outside the cell wall used for adherence and evasion of host defenses.
The membrane is a dynamic phospholipid bilayer with proteins and lipids moving laterally, allowing selective permeability.
Small, uncharged molecules like oxygen, carbon dioxide, and water.
They facilitate the selective passage of larger or charged molecules across the membrane.
Capsules are firmly attached glycocalyx layers; slime layers are loosely attached and more diffuse.
Movement of bacteria toward or away from chemical stimuli using flagellar motion.
The space between the inner and outer membranes containing enzymes and proteins involved in nutrient processing.
LPS is an endotoxin in the outer membrane that can trigger strong immune responses.