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Lipids

A fatty, waxy, or oily compound that will not dissolve in water. Lipids are a major part of biological membranes.

PubMed Health Glossary
(Source: NIH - National Institute of General Medical Sciences)

Image of parts of the cell membrane Click to enlarge

Parts of the cell membrane, showing the lipid layer National Institutes of Health

The cell membrane, also called the plasma membrane, is a cell's protective barrier. Click to enlarge

The cell membrane, also called the plasma membrane, is a cell's protective barrier. National Institutes of Health

About Lipids

Lipids are fat-like substances that are important parts of the membranes found within and between each cell and in the myelin sheath that coats and protects the nerves.

Lipids include oils, fatty acids, waxes, steroids (such as cholesterol and estrogen), and other related compounds. NIH - National Institute of Neurological Disorders and Stroke


About Lipids in the Cell Membranes

The cell's outer membrane is made up of a mix of proteins and lipids (fats). Lipids give membranes their flexibility. Proteins transmit chemical messages into the cell, and they also monitor and maintain the cell's chemical climate.

On the outside of cell membranes, attached to some of the proteins and lipids, are chains of sugar molecules that help each cell type do its job.
NIH - National Institute of General Medical Sciences

Terms to know

Carbohydrates
A molecule made up of one or more sugars. In the body, carbohydrates can exist independently or be attached to proteins or lipids.
Cell Membrane (Plasma Membrane)
The outer membrane of a cell.
Cells
The basic subunit of any living organism; the simplest unit capable of independent life. Although there are some single-celled organisms, such as bacteria, most organisms consist of many cells that are specialized for particular functions.
Cholesterol
Cytoplasm
The fluid inside a cell but outside the cell's nucleus. Most chemical reactions in a cell take place in the cytoplasm.
Nucleus
In biology, the structure in a cell that contains the chromosomes. The nucleus has a membrane around it, and is where RNA is made from the DNA in the chromosomes.
Phospholipids
A lipid (fat) that contains phosphorus. Phospholipids are a major part of cell membranes.
Proteins
A molecule made up of amino acids. Proteins are needed for the body to function properly. They are the basis of body structures, such as skin and hair, and of other substances such as enzymes, cytokines, and antibodies.
Triglycerides
One of the major forms of fat that is produced in the liver and found in the blood.

Terms to know

Carbohydrates
A molecule made up of one or more sugars. In the body, carbohydrates can exist independently or be attached t...
Cell Membrane (Plasma Membrane)
The outer membrane of a cell....
Cells
The basic subunit of any living organism; the simplest unit capable of independent life. Although there are s...
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