Summary
A stack of flattened membranes that modifies, sorts and packages proteins and lipids for secretion or delivery.
In depth
The Golgi consists of stacked cisternae with a cis (receiving) face toward the ER and a trans (shipping) face. Proteins move through the stack, picking up modifications such as glycosylation and phosphorylation, and are sorted into vesicles.
Tags such as mannose-6-phosphate direct enzymes to lysosomes, while others go to the membrane or are secreted. In plants the Golgi also makes cell wall polysaccharides.
Remember: ER makes, Golgi finishes, sorts and ships.
Two models describe movement through the Golgi: cisternal maturation, in which the cisternae themselves progress and change from cis to trans, and vesicular transport between stable compartments. Current evidence favours maturation with recycling vesicles carrying enzymes backward.
In plant cells the Golgi also builds the polysaccharides of the cell wall, and in sperm it forms the acrosome that helps penetrate the egg. Each cell can contain from one large stack to hundreds of dispersed stacks.
Key idea: the Golgi is the cell's post office, adding address labels (sugar and phosphate tags) and dispatching molecules in vesicles to their destinations.
Frequently asked questions
What is Golgi Apparatus?
A stack of flattened membranes that modifies, sorts and packages proteins and lipids for secretion or delivery.
Which area of biology covers Golgi Apparatus, and how advanced is it?
Golgi Apparatus is one of the 52 topics in Cell Biology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Lysosome, Eukaryotic Cell, Fluid Mosaic Model.
What should I learn before Golgi Apparatus?
Golgi Apparatus is a Beginner topic, so no earlier topic is required. Other Beginner topics in Cell Biology that pair well with it include Cell Theory, Prokaryotic Cell, Eukaryotic Cell.
What topics are related to Golgi Apparatus?
The closest topics to Golgi Apparatus are Lysosome, Eukaryotic Cell, Fluid Mosaic Model, Exocytosis. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Golgi Apparatus?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Golgi Apparatus. To practise the whole of Cell Biology, use the Cell Biology quiz.
How is Golgi Apparatus different from Lysosome?
Golgi Apparatus: A stack of flattened membranes that modifies, sorts and packages proteins and lipids for secretion or delivery. Lysosome: A vesicle filled with digestive enzymes that breaks down worn-out organelles, food particles and invaders. Read both side by side and note what each one explains.
How should I study Golgi Apparatus step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Lysosome and explain the difference aloud. Finally, take the Cell Biology quiz and come back to this page for any question you miss.