Atom To Cell.

In this blog, we will discuss about the difference between the atom and the cell. Why atom is not the fundamental unit of life? and a journey of an atom to a cell.

Firstly, what is the difference between an atom and a cell?

 Atom is the fundamental unit of the entire matter, whereas cell is the fundamental unit of living matter. which means every cell is made up of atoms, whereas every atom is not a cell.

Size of atom vs the size of cell

The size of the atom ranges between 10 to the power minus 14 meters i.e. picometer (pm) to 10 to the power of minus 10 meters i.e. Armstrong. To visualize it, magnify an apple to that of the size of Earth, And now the size of the original apple is probably the size of an atom of this giant apple (from the book: six easy pieces). Whereas the size of the cell ranges between 10 to the power of minus 6 meters i.e. micrometers to 10 to the power of minus 2 meters i.e. centimeters.

The overall conclusion about the size of atoms and cells is that an atom is way smaller than a cell because cells are made up of atoms, which obviously results in the above conclusion.

What makes some combination of atoms become a cell?

Before answering that question, let's understand the difference between the properties of any combination of atoms that make non-living matter and the specific combination of atoms that makes the cell.

Properties of cell

High level of organization and order: Though nonliving matter consists of some level of organization like specific molecular structure. but cells (i.e. living matter) consist of the right molecules in specific structures, interacting in a particular way to form highly organized structures like organelles that perform specific functions like energy production and waste removal.

Growth: A cell can grow internally that is it can take specific raw components from the environment into its highly organized system and break that component down to increase in mass (i.e. growth), repair, and sustain the system.

Response to stimuli: The cell as a system can respond to external information like light, chemical, and temperature changes. Based on a stimulus, the cell can undergo various changes like changes in movement change in internal chemical reactions, etc.

Reproduction: The cell contains information in the form of a specific molecular structure called DNA (deoxyribonucleic acid). It is the information about how to create a replica of a similar system.

So these are the major properties of cells that differentiate them from non-living matter.

So back to our question, What are the specific elements and their combinations and interactions that make non-living atoms living cells?

Basically, a cell consists of majorly five elements.

• Carbon
• Oxygen
• Hydrogen 
• Nitrogen
• Phosphorus 

And H2O combination of the second and third elements makes up 70% of the cell. Along with these major elements, there are other ions and elements present in a smaller quantity (but are also important). 

From these 5 major elements, 4 major molecules are formed. Since these four molecules make up a cell, which is the fundamental unit of life (i.e. bio). Therefore, these four molecules are called biomolecules.

• Carbohydrates
• Proteins
• Lipids and 
• Nucleic acid

Carbohydrates are formed by the interaction of carbon, hydrogen, and oxygen. And have a general formula as Cx(H2O)x 

Carbohydrates are basically a chain of specific molecules called monosaccharides, The Chain of these monosaccharides forms polysaccharides (carbohydrates). A monosaccharide is a monomer of carbohydrates, an example of a monosaccharide is glucose, which is used to make ATP. ATP is energy currency, thus making carbohydrates, a major energy source of energy for the cell.

(A monomer is a building block usually the same type of block that makes something larger. A polymer is a chain of Monomers combined to form a larger molecule.)

Lipids are biomolecules that are formed the by interaction of carbon, hydrogen, and oxygen. But unlike carbohydrates, they do not have a general common formula. Also, unlike any other biomolecules, they do not have a monomer, hence they do not form polymers. They are individual molecules.

Lipids are hydrophobic, that is, they do not dissolve in water. Also, lipids act as long-term energy storage for cells.

Proteins are biomolecules that are formed by the interactions of carbon, hydrogen, oxygen, and nitrogen, and have a general formula as RCH(NH2)COOH, R refers to the side chain, which differs for different proteins.

The monomer of protein is an amino acid. Protein has many functions in the living system but one of its main functions is to fight pathogens (disease-causing organisms). These pathogens-fighting proteins are specifically called antibodies.

Nucleic acids are biomolecules that are formed by interactions of carbon, hydrogen, oxygen, nitrogen, and phosphorus. The monomer of nucleic acid is a nucleotide. There are two types of nucleic acids DNA and RNA. Deoxyribonucleic acid (DNA) stores information about building and maintaining organism. Ribose nucleic acid (RNA) plays an important role in the production of protein (Protein synthesis) along with other functions.

These 4 major biomolecules, which are made up of mainly 5 different types of atoms namely carbon, hydrogen, oxygen, nitrogen, and phosphorus, combine to interact magically so that they make the fundamental unit of life, which can organize, grow, reproduce, and respond to external information. Thus make a non-living atom a living cell.

We cannot pinpoint a particular phase, process, or component and say, this is where the transition from non-living to living happened because the transition is not a point but the transition is the entire process of interaction of atoms in a specific way, forming specific structure and eventually forming a certain system that we define as life.

This brings us to the magic of interaction, most of the properties emerge out of interactions. 

All magical phenomena, especially living phenomena, emerged due to underlying interactions.

The properties of a cell are not present in the constituent atoms but emerge out of the interaction of those atoms and molecules. Properties of tissues are not present in constituent cells but arise as a result of interaction among the constituent cells. Interaction results in emergent properties at a higher level of organization.

In conclusion, life emerged from a lifeless atom as these atoms interact with each other wonderfully and magically.