Cell Biology: Membranous Organelles

Study Notes

Membranous Organelles

Mitochondria: Known as "cellular power plants," they produce about 95% of a cell's ATP, essential for energy.
Nucleus: Houses chromosomal DNA (chromatin) and nucleolus; crucial for genetic information transmission.
Endoplasmic Reticulum (ER): Comprised of tubules and vesicles, it plays a role in synthesis, storage, transport, and detoxification.
Golgi Apparatus: Made of flattened membrane-bound stacks (cisternae), it packages materials for lysosomes and secretory vesicles.
Lysosomes: Membrane-walled sacs filled with digestive enzymes that digest unwanted substances, including organelles and pathogens.
Peroxisomes: Small sacs containing oxidases and catalases that detoxify harmful peroxides.

Non-Membranous Organelles

Cytoskeleton: An internal protein network that provides support, shape, and intracellular movement within the cell.
Ribosomes: Complexes of RNA and proteins that act as sites for protein synthesis; can be free in the cytosol or fixed to the ER.
Centrioles: Barrel-shaped structures involved in cell division and the formation of cilia and flagella.
Cilia: Hair-like projections that facilitate fluid movement across cell surfaces through rhythmic beating.
Flagella: Whip-like structures that propel cells through fluid environments.
Microvilli: Tiny projections that increase cell surface area, aiding in absorption and secretion.

Specialized Features of Organelles

Mitochondrial Matrix: The inner space critical for ATP production, containing ATP synthase.
Rough ER: Ribosome-studded, responsible for synthesizing and packaging proteins for secretion.
Smooth ER: Lacks ribosomes; involved in lipid synthesis, metabolism, and detoxification processes.

Fiber Types in Cytoskeleton

Microtubules: Protein tubulin polymers providing cell shape, organelle movement, and aiding in cell division.
Microfilaments: Composed of actin, contributing to cellular structure and movement.
Intermediate Filaments: Provide mechanical strength and support for organelles, aiding in material transport.
Thick Filaments: Primarily made of myosin; involved in muscle contraction and cell movement.

Functional Aspects of Organelles

Transport vesicles: Move materials between the RER and Golgi apparatus.
Digestive function of lysosomes: Break down various cellular components and pathogens.
Cilia and flagella movement: Essential in various cellular processes, including locomotion and nutrient movement across surfaces.

Description

Test your knowledge on membranous and non-membranous organelles in cells. This quiz covers key functions and structures such as mitochondria, the nucleus, and lysosomes, providing a comprehensive overview of cell biology. Perfect for biology students seeking to reinforce their understanding of cellular components.