Organelles Flashcards
Ribosomes
Function: Synthesize proteins by translating messenger RNA (mRNA).
Structure: Small, round structures made of RNA and proteins; found floating in the cytoplasm or attached to the rough endoplasmic reticulum (RER).
Rough ER
Function: Synthesizes and modifies proteins; transports them to the Golgi apparatus.
Structure: Network of membranes covered in ribosomes.
Smooth ER
Function: Synthesizes lipids and detoxifies toxins.
Structure: Network of membranes without ribosomes.
Golgi Apparatus
Function: Modifies, sorts, and packages proteins and lipids for transport.
Structure: Stacked, membrane-bound sacs (cisternae).
Mitochondria
Function: Produces ATP (energy) through cellular respiration.
Structure: Double-membraned; inner membrane has folds (cristae) to increase surface area.
Lysosomes
Function: Digests and recycles cellular waste and foreign materials.
Structure: Membrane-bound sacs filled with digestive enzymes.
Peroxisomes
Function: Breaks down fatty acids and neutralizes toxins (e.g., hydrogen peroxide).
Help in the metabolism of lipids .
Vacuoles
Function: Stores water, nutrients, and waste; helps maintain cell pressure (turgor).
Structure: Large membrane-bound sac (prominent in plant cells).
Cytoskeleton
Function: Provides cell shape, movement, and intracellular transport.
Structure: Network of protein filaments (microtubules, microfilaments, intermediate filaments).
Centrosome
Structure
The centrosome is an organelle found in animal cells, located near the nucleus.
Function
Microtubule Organization: Acts as the main microtubule-organizing center (MTOC), regulating the formation and organization of microtubules.
Cell Division: Plays a crucial role in mitosis and meiosis by organizing the spindle fibers that separate chromosomes.
Cytoskeleton Support: Helps maintain cell shape and assists in intracellular transport.
Flagellum and Cilia
Used for locomotion, moving particles
elongated, motile structures that extend from the cell surface – cilia are shorter than flagella and occur in greater numbers
Movements of a flagellum propel a cell through a watery medium – the tail of a sperm cell is a flagellum
Cilia move fluids over the cell surface – cilia line the air passages of the lungs and sweep out mucus containing bacteria, dust particles, and other contaminants
Nucleus
Contains the cell’s genetic material (DNA).
Controls cellular activities such as growth, metabolism, and reproduction through gene expression.
