Discovery of cell
All biological things are composed of fundamental structural and functional units called cells.
The fundamental units of life, cells perform the functions required for an organism to survive.
The 17th-century work of scientists Anton van Leeuwenhoek and Robert Hooke is credited with the discovery of the cell.
Robert Hooke (1665): The first observation of cells is attributed to English scientist Robert Hooke. When he examined a thin slice of cork (the bark of the cork oak tree) in 1665 using a crude microscope, he saw tiny, box-like structures. He gave these constructions the name “cells” because they resembled the little chambers or cells seen in monasteries. It’s crucial to remember that Hooke mostly examined dead plant cells since his microscopes lacked the power to view live cells.
Anton van Leeuwenhoek (1674–1683): Dutch scientist Anton van Leeuwenhoek made substantial advancements in microscope design and attained substantially higher magnification. For the first time, he saw live cells between 1674 and 1683. By analyzing a variety of materials, including as blood, sperm, and pond water, Leeuwenhoek discovered a hitherto undiscovered world of microbes. He called these little creatures “animalcules.”
A key idea in biology, the cell theory was developed later in the 19th century and is commonly credited to Rudolf Virchow, Theodor Schwann, and Matthias Schleiden.
1838 Matthias Schleiden:Schleiden, a German botanist, postulated that cells make up all plants.
In 1839, Theodor Schwann;According to German biologist Schwann, all creatures are composed of cells, which is an extension of the cell hypothesis.
Virchow, Rudolf (1855):Virchow, a German doctor, advanced the cell hypothesis by claiming that all cells originate from pre-existing cells.
Collectively, these researchers’ efforts established the groundwork for our current understanding of cells and cell biology.
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Cell and its major three parts
Cell Membrane (Plasma Membrane)
Synopsis:The cell membrane, which divides the inside environment of the cell from the exterior environment, is the outermost barrier of the cell. It is a selectively permeable barrier that regulates material input and outflow, enabling the cell to preserve its internal environment.
Use:The movement of gasses, nutrients, and waste materials is controlled by the cell membrane. It is also essential for cell identification and communication.
Cytoplasm:
Synopsis:The gel-like material that envelops the cellular organelles and fills the cell is called the cytoplasm. It is made up of different cellular structures, organic compounds, ions, and water.
Use:The cytoplasm facilitates intracellular transport and support in addition to acting as a medium for the suspension of cellular organelles.
Nucleus:
Synopsis:
A membrane-bound organelle that is often found close to the cell’s center is the nucleus. DNA, or deoxyribonucleic acid, is the genetic substance of the cell.
Use:As the hub of the cell, the nucleus coordinates all cellular functions and controls gene expression. It is in charge of passing genetic information to the following generation of cells.
Additional membrane-bound structures called organelles are found in eukaryotic cells and provide particular purposes for the cell. The endoplasmic reticulum, the Golgi apparatus, mitochondria, chloroplasts (in plant cells), lysosomes, and other organelles are a few of the key ones. These organelles support a number of cellular functions, including waste elimination, energy generation, and protein synthesis.
Prokaryotic cells have a simpler structure and don’t have membrane-bound organelles or a genuine nucleus. The nucleoid is the area that contains their genetic material. Typically, prokaryotic cells are found in archaea and bacteria.
Cell and its organization
Types of Cells:
Prokaryotic Cells:
- Characteristics:
- Lack a true nucleus.
- Lack membrane-bound organelles.
- Found in bacteria and archaea.
- Characteristics:
Eukaryotic Cells:
- Characteristics:
- Have a true nucleus where genetic material is enclosed in a membrane.
- Contain membrane-bound organelles.
- Found in plants, animals, fungi, and protists.
- Characteristics:
Major Parts of a Cell
Plasma Membrane, or cell membrane:
Synopsis:outside edge of the cell.
barrier with selective permeability.
Use:controls the movement of chemicals in and out.
makes cell communication easier.
Cytoplasm
Synopsis:A gel-like material that occupies the cell.
has organic compounds, ions, and water in it.
Use;maintains the organelles of cells.
engaged in the movement inside cells.
Center:
Synopsis:organelle linked to a membrane.
includes genetic material, or DNA.
Use:the cell’s central control unit.
controls the expression of genes and biological processes.
Organelles: Cells that are eukaryotic
The ER (endoplasmic reticulum):engaged in the production of lipids and proteins.
Golgi apparatus:transports, assembles, and modifies proteins.
The mitochondria;creates ATP at the site of cellular respiration.
Plant cells called chloroplasts:contains chlorophyll and is the site of photosynthesis.
Lysosomes:include digestive enzymes that are found inside cells.
Plant cells, or vacuumoles:Nutrient and waste product storage.
Conclusion:
An understanding of the composition and arrangement of cells is essential to the study of biology.
Although different, cells have many characteristics, and studying them is essential to comprehending how life functions.
These notes give a general overview of the structure and function of the cell, including main components, evolution of the cell theory, and both prokaryotic and eukaryotic cells.