The Building Blocks Of All Living Things

1472 WordsSep 8, 20156 Pages
Cells are the building blocks of all living things. They are the smallest structural and functional unit of an organism, which is normally microscopic and consists of many components. Some of these components are called organelles which are specialized structures that perform certain tasks within the cell. All cells, and components, are surrounded by a structure called the cell membrane, or plasma membrane, which serves as a boundary between the cell 's internal and external environments. Cell membranes are based on a framework of fat-based molecules called phospholipids, which prevent hydrophilic, substances from entering or escaping the cell. These membranes are also covered with proteins that act as gatekeepers, determining what substances can and cannot cross the membrane, markers which identify the cell as part of the same organism or another, and others work like fasteners, binding cells together so they can function as one. Also, other membrane proteins work as communicators, sending and receiving signals from neighboring cells and the environment. Within the membrane, a cell 's interior environment is a water based substance called the cytoplasm, this liquid environment is full of cellular machinery and structural elements. Cells also contain many other components inside their membrane such as Nucleic acids, proteins, carbohydrates & lipids. Nucleic acids which are the molecules, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA and RNA contain and help

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