Cell structure

Cell Structure is the basic unit of life in all living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as bacteria and yeast, are unicellular, which means they consist of a single cell. Other organisms, like humans, are multicellular, or have many cells—an estimated 100,000,000,000,000 cells!

Overview

The cell is the basic structural, functional, and biological unit of all known living organisms. Cells are the smallest units of life that can replicate independently, and are often called the "building blocks of life". The study of cells is called cell biology.

Cell Components

Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Cells also have other smaller structures called organelles. These include the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes.

Nucleus

The nucleus is the largest organelle in the cell and it contains the cell's chromosomes, and is the site of RNA synthesis.

Mitochondria

Mitochondria are organelles that act like a digestive system which takes in nutrients, breaks them down, and creates energy for the cell.

Endoplasmic Reticulum

The endoplasmic reticulum (ER) is a type of organelle in the cells of eukaryotic organisms that forms an interconnected network of flattened, membrane-enclosed sacs or tubes known as cisternae.

Golgi Apparatus

The golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1897 by the Italian scientist Camillo Golgi.

Lysosomes and Peroxisomes

Lysosomes are cellular organelles that contain acid hydrolase enzymes to break up waste materials and cellular debris. Peroxisomes are small, membrane-enclosed organelles that contain enzymes involved in a variety of metabolic reactions, including several aspects of energy metabolism.

Cell Types

There are two types of cells: prokaryotes and eukaryotes. Prokaryotes are single-celled organisms without a nucleus or other organelles enclosed within membranes. Eukaryotes have a nucleus enclosed within a membrane and other membrane-bound organelles.

See Also

• Cell membrane
• Cell division
• Cell cycle
• Cell growth