Top 20 Organelles

Phagocyte

Cell that intakes materials from outside the cell

Hydralytic enzomes

Enzymes used in the breakdown of macromolecules.

Plasma Membrane

Function: Boundary of the cell, transports nutrients etc. in/out of the cell via transport proteins, and is involved in cell-cell communication and adhesion. Made of: lipid bilaryer (phosopholipids, sphingolipids (glycolipids), sterols) and embedded proteins.

Proteasomes

Function: Digestion od old cytoplasmic proteins. Special features: It has no membrane, and is instead a large multi-protein complex. The protein Ubiguitin flags older proteins to be destroyed.

Cell Wall

Function: For support and protection of the cell. Made of: In plants, cellulose. In fungi, chitin. In bacteria, peptidoglycan.

Chloroplast

Function: Found in plants, for photosynthesis. The thylakoids contain chlorophyll, and synthesize ATP. The stroma synthesize sugar and catalyze CO2 fixation. Special features: Contains both thylakoids and stroma, has its own DNA and ribosomes, intakes photons to generate ATP. Used in concert with mitochondria to maximize ATP production.

Rough Endoplasmic Reticulum:

Function: Makes membrane proteins which are translocated across the ER into the lumen or stay embedded in the ER membrane, makes export proteins, makes lysosomes. Special Features: Covered in ribosomes

Flagella and cilia

Function: Movement and adhesion Special features: in Eukaryotes, they are complicated structures and powered by ATP. In prokaryotes, they are made of flagellin and driven by protons.

Peroxisomes

Function: Perform biochemical reactions to generate peroxide from fatty acids. Catalase then converts the H2O2 to H2O. Special features: Cells in the ammune system have lots of peroxisomes, as well as bleach.

Golgi Apparatus

Function: Protein modification (glycosylation) and sorting for export or lysosomes.

Lysosome

Function: Serves as the cell's stomach, digesting endocytosed material, used in autophagy. Special features: They are acidic with many protons floating in them, and are acked with hydralytic enzymes.

Smooth Endoplasmic Reticulum:

Function: Sometimes breaks down glycogen, produces lipids, contains enzymes for detoxification. Liver cells contain high amounts of SER. Special features: not covered in ribosomes.

Vacuole

Function: Storage and turgor. Special features: Only found in plants.

Cytoskeleton

Function: Support, movement, and transport. Special features: There are 3 parts: Actin microfilaments (made of chains of actin wound around each other), microtubules (made of plates) and intermediate filaments (made of various proteins, such as keratin). During cell division, the polymerization of actin microfilaments pushed the membrane forward.

Mitochondria

Function: Synthesize ATP by oxidative phosphoryllation in cristae membranes, creates its own proteins. Special features: typically 1-2 um long, can make own proteins, have own set of DNA and ribosomes.

Ribosomes

Function: Used in translation along with tRNA and mRNA to link amino acids in the correct order. Made of/Special features: 2 Types - free-floating and stuck to surface of RER. Formed in the nucleus, and uses tRNA and the genetic code.

Cell junctions

Function: cell-cell adhesion and communication.

Vesicles

Function: transport of materials between compartments.

Nucleus

Functions: Assembles ribosomes, contains the genetic code (DNA). Made of: Nucleolus (synthesizes ribosomal RNA + ibosomes), chromatin, chromosomes, nuclear envelops, nuclear pores (allows for transport in/out of nucleus).

Cytosol

Gel-like matrix of the cell

Extracellular matrix

In animal cells, used extensively in epithelial cells.

Phagocytosis

Intaking large molecules

endocytosis

Intaking small molecules

Centrioles

Microtubule organizing centers

Spindle

Separation of chromosomes.

Endoplasmic Reticulum

Two types: Rough ER and Smooth ER.