[[Cell Structure and Function]]

Cell compartmentalization is how eukaryotic cells use membranes to separate specific metabolic processes and enzymatic reactions.

# Summary
* Internal membranes help cells separate competing interactions and increase surface area where reactions occur
* Each organelle maintains its own conditions
* Folded membrane like mitochondrial cristae and chloroplast thylakoids pack more reaction surface into a small space
* Prokaryotes lack membrane bound organelles, so translation and transcription can occur in the same space
# Eukaryotic Organization: Separate Compartments for Separate Jobs
Eukaryotic cells have membranes, prokaryotic cells don't. Eukaryotic cells have organelles which are compartmentalized because they're surrounded by a membrane.

# Nucleus
* Houses DNA and cell control
* Surrounded by a double membrane with nuclear pores for transport
* Creates a protected environment for DNA storage and RNA production
* Separates transcription (making DNA from RNA) from translation (making proteins from RNA)
# Endoplasmic Reticulum
* Rough ER creates specialized area for protein folding and quality control. Connects directly to nuclear membrane for efficient RNA transport.
* Smooth ER no ribosomes, specializes in lipid production and detoxification. Separate environment for lipid synthesis enzymes, stores calcium ions in a controlled safe space.
# Golgi Apparatus
* Receives proteins from ER and modifies them
* Sorts and packages proteins into vesicles for delivery
* Works a sequential processing line with enzymes in different cisternae
* Different cisternae have different conditions for different processing steps
# Lysosomes
* Contains hydrolytic enzymes that work best in acidic environments
* Breaks down cellular waste, old organelles, and foreign material
* Keeps destructive enzymes safely contained
# Mitochondria
* Generates ATP from aerobic respiration
* Double membrane, outer is smooth and protective, inner is folded into a cristae to increase SA
* Contains own DNA and ribosomes (evidence they evolved from once free living prokaryotes)
# Peroxisomes
* Breaks down fatty acids and toxic molecules
* Enzymes that produce and break down hydrogen peroxide
* Safe contained place for these dangerous reactions
# Vacuoles
* Stores nutrients waste products and water
* Helps maintain turgor pressure in plant cells
* Isolated environment for materials that might hamper other processes

# Why Compartmentalization Improves Efficiency
* Creates specialized environments (e.g. enzymes like acidic environments, others don't)
* Increases surface area for reactions
* Separates competing reactions, some processes would interfere with others
* Allows proteins to go where they're needed as the membranes hold proteins
* Prokaryotic cells can do translation and transcription in the same region because they lack compartmentalization, limiting how complex they can become.

| Term                            | Definition                                                                                                                                    |
| ------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- |
| compartmentalization            | The division of the eukaryotic cell into distinct membrane-bound regions that separate different metabolic processes and enzymatic reactions. |
| enzymatic reaction              | Chemical reactions catalyzed by enzymes that occur within specific cellular compartments to facilitate metabolic processes.                   |
| eukaryotic cell                 | Cells that contain a membrane-bound nucleus and internal membrane-bound organelles, found in animals, plants, fungi, and protists.            |
| internal membrane               | Membranes within eukaryotic cells that divide the cell into compartments with specialized functions.                                          |
| intracellular metabolic process | Chemical reactions and pathways that occur within the cell to build up or break down molecules for energy and biosynthesis.                   |
| membrane-bound organelle        | Specialized structures within eukaryotic cells enclosed by a membrane that perform specific cellular functions.                               |
| membrane-bound structure        | Organelles and compartments in eukaryotic cells that are enclosed by a lipid bilayer membrane, separating their contents from the cytoplasm.  |
| organelle                       | Membrane-bound or non-membrane-bound structures within eukaryotic cells that perform specific cellular functions.                             |
| surface area                    | The total area of a membrane available for chemical reactions and cellular processes to occur.                                                |