Discovery of Cells and Cell Theory

In this discovery of cells and cell theory post we have briefly explained about cell theory, discovery of cells, microscopes role in discovery of cells, and structures shared by all cells.

The first time the term “cell” was employed to describe these small living units was in 1665 by British scientist Robert Hooke. Hooke was among the first scientist to research living organisms under microscopes. The microscopes of the time were not the most powerful; however, Hooke was able to make a major discovery. As he looked at the cork’s thin slices under the microscope, Hooke was astonished to find what appeared to be oblong. Hooke created the sketch in the image below to illustrate what he observed. You can see the cork was made of various tiny pieces of which Hooke called cells.

Then, shortly after Robert Hooke discovered cells in cork, Anton van Leeuwenhoek in Holland discovered other significant discoveries using the microscope. Leeuwenhoek created his microscope lens, and he was so skilled in his craft that his instrument was much stronger than any other microscope of the day. The microscope of Leeuwenhoek was nearly as powerful as the modern light microscopes. With the microscope, Leeuwenhoek became the first to study bacteria and human cells.

Discovery of Cells and Cell Theory

In the 1900s, researchers began to observe the cells of various living organisms. These scientists’ findings inspired two German scientists known as Theodor Schwann and Matthias Jakob Schleiden to believe that cells constitute the primary components of the living world. In 1850 the German doctor named Rudolf Virchow studied cells under a microscope and observed them multiplying and making new cells. He discovered that living cells generate new cells via division. Virchow suggested that living cells only arise from living cells based on this knowledge.

Discovery of Cells and the Development of Cell Theory

Discovery of Cells and Cell Theory; Robert Hooke sketched these cork cells as they appeared under a simple light microscope. Image Source: https://en.wikipedia.org/wiki/Micrographia

The theories of all three of them Schwann, Schleiden and Virchow have to lead to the cell theory, which is one of the main theories that connect all of biology.

Every organism is made up of cells.

All life-giving activities of living organisms are carried out inside cells.

Every cell is derived from existing cells.

Microscopes Role in Cell Discovery

From the time of Robert Hooke’s discovery in the 1600s, the microscope opened an exciting new life-world at the level of cells. As microscopes improved, they made more discoveries regarding the living cells of things. But by the end of the 1800s, optical microscopes were reaching their limits. Things that were smaller than cells, such as the cell’s structures, could not be observed with the most powerful microscope.

In the 1950s, a brand new kind of microscope was developed. The electron microscope was its name; the microscope utilized an electron beam rather than light beams to see tiny objects. Through an electron microscope, scientists could see tiny cells’ structures, and scientists could observe tiny molecules and Atoms. The electron microscope had a significant impact on the field of biology. It helped scientists analyse organisms based on their molecules. It also created the cell biology field. Through the electron microscope, numerous discoveries in cell biology were made. 

Structures Shared By All Cells

While cells vary, however, they all have some common elements. They include a cell’s Cytoplasm, plasma membrane DNA, and ribosomes.

Plasma membrane: Plasma membrane (also known as “the membrane of the cell”) can be described as a microlayer of phospholipids surrounding the cell. It is the physical boundary that separates the cells from the environment and is a reason to imagine it as being the “skin” of the cell.

Cytoplasm: The Cytoplasm is the cell material within the plasma membrane. The Cytoplasm comprises a fluid substance called the cytosol and contains various cell structures, including Ribosomes.

Ribosomes: Ribosomes are a type of structure in the Cytoplasm, where proteins are created.

DNA: DNA can be described as nucleic acids that are found within cells. It is the source of genetic instructions that cells require to create proteins.

Further Readings