Cells And Their Structure Flashcards
What are ribosomes
Dense particles consisting of two subunits, each composed of ribosomal RNA and proteins; can be free or it can be attached to the ER; site of protein synthesis
What is the Rough ER
Coiling membrane system with ribosomes attached;proteins synthesized are packaged into vesicles for transport to the Golgi Apparatus
What is the Smooth ER
Coiling membrane system lacking ribosomes; synthesizes lipids and carbohydrates
What is the Golgi apparatus
Stack of smooth membrane sacs adjacent to the nucleus l; modifies synthesized proteins, then packages the proteins in vesicles for transport around/out of the cell
What are lysosomes
Membranous sacs containing hydrolytic enzymes used in cell digestion
What are peroxisomes
Membranous sacs containing oxidative enzymes (per oxidase) that degrade toxic compounds such as hydrogen peroxide
What are vesicles
Membrane bound sacs that transport cellular material
What are microfilaments
Filaments containing the contractile protein actin; part of the Cytoskeleton and functions in intracellular movement
What are intermediate filaments
Protein fibers that provide strength, stabilize the position of organelles, and transport materials within the cytoplasm
What are microtubules
Hollow tubes composed of the globular protein Tubulin; provide strength and rigidity and anchoring major organelles
What are thick filaments
Large long strands of myosin protein found in muscle cells that interact with thin actin filaments to produce muscle contraction
What are centrioles
Cylindrical structures composed of nine triplets of microtubules;they direct the movement of DNA during cell division as well as form the bases of cilia and flagella
What are microvilli
Small, finger-shape projections of the cell membrane that actively absorb fluid and nutrients
What is cilia
Cell surface projections composed of microtubules; thy move to propel substance across the cell surface
What is flagella
Larger and longer cilia that provides cellular locomotion
