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.