Golgi Apparatus

Structure

· Is made up of flattened, membrane bound-sacs = cisternae .

· It has three regions:

o Cis-Golgi (receiving side) – receives vesicles from ER

o Medial-Golgi – modifies proteins and lipids

o Trans-Golgi (shipping side) packages and sends molecules to their final destinations.

Functions

· Protein Processing and Modification: Adds carbohydrates (glycosylation) and phosphate groups (phosphorylation) to proteins.

· Sorting and Packaging: sends proteins to lysosomes, plasma membranes or secretions.

· Lipid Transport: Modifies lipids from the ER

Organelle	Structure	Function	Relevance
Mitochondria	Double membrane, cristae, matrix, own DNA (mtDNA)	ATP production via cellular respiration	Mitochondrial diseases (e.g., Leigh syndrome)
Rough ER	Ribosome studded membrane network	Protein synthesis and transport	ER stress (Alzheimer’s, Type 2 Diabetes)
Smooth ER	No ribosomes, tubular structure	Lipid synthesis, detoxification, calcium storage	Drug detoxification in liver
Golgi Apparatus	Stacked, flattened sacs	Modifies, sorts and packages proteins	Protein misfolding in Alzheimer’s & Parkinson’s