Apart from producing its own energy, it also produces a high-energy compound called ATP (adenosine triphosphate) which can be used as a simple energy source elsewhere.

These are the powerhouses of the cell and break down nutrients to yield energy. Perioxisomes are formed directly from the endoplasmic reticulum rather than from the Golgi apparatus like lysosomes. These organelles are very similar to the lysosomes and contain enzymes that act together in the form of hydrogen peroxide to neutralize substances that may be toxic to the cell. It contains enzymes that are not used within the cell but emptied outside of the cell, for example the secretory vesicles of the pancreatic acinar cell release digestive enzymes which help with the digestion of nutrients in the gut. Lysosomes contain enzymes that help with the digestion of nutrients in the cell and break down any cellular debris or invading microorganisms like bacteria.Ī structure that is similar to a lysosome is the secretory vesicle. It varies in size and function depending on the type of cell. Lysosomes are vesicles that break off from the Golgi apparatus. In this way, the products from the ER are stored in the Golgi apparatus and converted into different substances that are necessary for the cell’s various functions. It is closely associated with the endoplasmic reticulum in that substances produced in the ER are transported as vesicles and fuses with the Golgi apparatus. The Golgi apparatus is a stacked collection of flat vesicles. The smooth ER also plays a role in carbohydrate and drug metabolism. Its function is to synthesize different types of lipids (fats). The smooth endoplasmic reticulum (SER / agranular ER) does not have any attached ribosomes.Its function is to synthesize new proteins. These parts of the endoplasmic reticulum contain a number of ribosomes giving it a rough appearance. The rough endoplasmic reticulum (RER / granular ER) contains a combination of proteins and enzymes.There are two types of endoplasmic reticulum – rough (granular) and smooth (agranular). Its structure is such that substances can move through it and be kept in isolation from the rest of the cell until the manufacturing processes conducted within are completed. The endoplasmic reticulum (ER) is a membranous structure that contains a network of tubules and vesicles. The lipid molecules on the outer and inner part (lipid bilayer) allow it to selectively transport substances in and out of the cell. It is a double-layered membrane composed of proteins and lipids. The cell membrane is the outer coating of the cell and contains the cytoplasm, substances within it and the organelle. One of the few cells in the human body that lacks almost all organelles are the red blood cells.ĭiagram of the human cell illustrating the different parts of the cell. All the organelles are suspended within a gelatinous matrix, the cytoplasm, which is contained within the cell membrane. The cell contains various structural components to allow it to maintain life which are known as organelles. Despite this structural organization, all activity boils down to the cell – a complex unit that makes life possible. Masses of tissue work collectively to form an organ that performs specific functions in the body. A collection of cells that function together to perform the same activity is known as tissue.

Other non-cellular components in the body include water, macronutrients (carbohydrates, proteins, lipids), micronutrients (vitamins, minerals) and electrolytes. Humans are multicellular organisms with various different types of cells that work together to sustain life. The cell is the basic functional in a human meaning that it is a self-contained and fully operational living entity.

Cell diagram labeled