Cell Organelles
By: Jamie Kaplan
And
Terry Zhou
Nucleus
• The central membrane-bound organelle that manages or controls cellular functions
• Contains most of the cell’s genetic material
Nucleolus
• It’s inside the nucleus• Surrounded by a layer
of chromatin• Main function is to
produce ribosomes
Ribosomes
• The sites where the cell produces proteins according to the directions of DNA.
Cytoplasm
• The clear, gelatinous fluid inside a cell
• Makes up almost 70% of the cell
• All the functions for cell expansion, growth and replication are carried out in the cytoplasm
Rough Endoplasmic Reticulum
• The surface of the rough endoplasmic reticulum is studded with protein-manufacturing ribosomes giving it a "rough" appearance
• Its function is protein translating, folding, and transport of proteins to be used in the cell membrane
Smooth Endoplasmic Reticulum
• Does not have ribosomes
• functions in several metabolic processes, including synthesis of lipids, metabolism of carbohydrates and calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins
Golgi Apparatus
• The primary function of the Golgi apparatus is to process and package macromolecules such as proteins and lipids made by the cell.
Plasma Membrane
• Selectively permeable • Made up of mostly
phospholipids • Found in all cells• Physically separates
the intracellular components from the extracellular environment
• Functions as the “skin”
Vacuoles
• Membrane-bound compartments within some eukaryotic cells that can serve a variety of secretory, excretory, and storage functions
• Is found in large sizes in plant cells
In a plant cell
In an animal cell
Lysosomes
Lysosomes are organelles containing digestive enzymes. They use these enzymes to get rid of
unneeded food, engulfed viruses, and old, unneeded organelles, etc. They are membrane-bound, to prevent
them from accidentally digesting the cell itself.
Chloroplasts
Chloroplasts are plastids that supply a plant’s energy. They do this by combining absorbed sunlight with
carbon dioxide and water, creating sugar. They are organelles unique to plants and eukaryotic organisms
such as algae and certain bacteria.
Mitochondria
Mitochondria are very vital organelles that transform energy within a cell. They are the source of most of the cell’s energy, and while from the outside seem
rather simple, their insides are a mass of folds.
Here we see a simplified model.
Mitochondria in cells can vary in number from one to thousands. They are also unique in the fact that they
have their own DNA, which resembles that of a bacteria.
Cytoskeleton
The cytoskeleton is a network of microtubules and microfilaments, made of protein, and found in
eukaryotic cells, as well as some prokaryotic ones. While not pointed out that often, it is vital to the cell
for all the functions it performs.
Not only does it support the cell and protect it to a certain extent, it
facilitates cell movement both inside and outside the cell, utilizing cilia and
flagella for outward movement and transporting materials throughout the
cell.
Microtubules
Microtubules are hollow protein tubes that are part of the structure of the cytoskeleton. They assist in many
forms of cell movement and replication.
Microfilaments
Microfilaments are thinner than microtubules, but serve much the same purposes. Like microtubules, they are
sometimes made of keratin (the material that makes up your fingernails), and they serve purposes in various
aforementioned cell functions. They are found just below the cell membrane, and are the main shock absorbers.
Centrioles
Centrioles are barrelish organelles found in pairs, which duplicate when the cell splits. The older
centriole, or the mother centriole, creates flagella and cilia.
Cilia
Cilia have two main purpose. Some cilia are used for locomotion, while others are used as sensory organs,
like bug antennae.
Flagella
Flagella are longer and much less numerous than cilia, but serve much the same purpose. Most eukaryotic cells have only one or two, while prokaryotes and
bacteria can have many more, and use them to move about.
Plastids
Plastids are very variable organelles found in plant cells. Their main purposes are to store and create
substance, and to initiate photosynthesis. They range from…
…chloroplasts, found in many plants as a green pigment…
…to statoliths, which detect gravity.