CELL BIOLOGY: HISTORY, WHAT IT STUDIES, APPLICATIONS AND CONCEPTS - BIOLOGY - 2025

The Cell Biology is the branch of biology that studies all aspects of cell life. That is, with the structure, function, evolution and behavior of the cells that make up living beings on earth; in other words, everything inherent in his birth, life and death.

It is a science that integrates a large amount of knowledge, among which biochemistry, biophysics, molecular biology, computational sciences, developmental and behavioral biology and evolutionary biology stand out, each of which with its own approach and their own experimentation strategies to answer specific questions.

Silhouette of a microscope (Source: Karen Arnold via Wikimedia Commons)

Since the cell theory states that all living things are composed of cells, cell biology does not distinguish between animals, plants, bacteria, archaea, algae or fungi and can focus on individual cells or on cells belonging to tissues and organs of the same multicellular individual.

Thus, since it is an experimental science (rather than descriptive), research in this branch of biology depends on the methods available for the study of cell ultrastructure and its functions (microscopy, centrifugation, culture in vitro, etc.)

History of cell biology

Some authors consider that the birth of cell biology took place with the advent of the cell theory proposed by Schleiden and Schwann in 1839.

However, it is important to consider that the cells were described and studied many years earlier, beginning with the first findings of Robert Hooke who, in 1665, saw for the first time the cells that constituted the dead tissue of a cork sheet; and continuing with Antoni van Leeuwenhoek, who years later observed samples with different microorganisms under the microscope.

Portrait of Robert Hooke (Source: Gustav VH, via Wikimedia Commons)

After the work of Hooke, Leeuwenhoek Schleiden and Schwann, many authors also devoted themselves to the task of studying cells, with which details regarding their internal structure and functioning were refined: the nucleus of eukaryotic cells, DNA and chromosomes, mitochondria, endoplasmic reticulum, Golgi complex, etc.

In the mid-20th century, the field of molecular biology saw considerable progress. This influenced that, during the 1950s, cell biology also experienced considerable growth, since during those years it was possible to maintain and multiply cells in vitro, isolated from living organisms.

Advances in microscopy, centrifugation, formulation of culture media, protein purification, identification and manipulation of mutant cell lines, experimentation with chromosomes and nucleic acids, among other things, set a precedent for the rapid advancement of cell biology to the current era.

What do you study? (object of study)

Cell biology is responsible for the study of prokaryotic and eukaryotic cells; he studies the processes of his formation, his life and his death. It can usually focus on signaling mechanisms and the structuring of cell membranes, as well as the organization of the cytoskeleton and cell polarity.

It also studies morphogenesis, that is, the mechanisms that describe how cells develop morphologically and how cells that "mature" and transform throughout their lives change over time.

Yeast cells of the species Saccharomyces cerevisiae.

Cell biology includes topics related to mobility and energy metabolism, as well as the dynamics and biogenesis of their internal organelles, in the case of eukaryotic cells (nucleus, endoplasmic reticulum, Golgi complex, mitochondria, chloroplasts, lysosomes, peroxisomes, glycosomes, vacuoles, glyoxysomes, etc.).

It also involves the study of genomes, their organization, and nuclear function in general.

In cell biology, the shape, size and function of the cells that make up all living organisms are studied, as well as the chemical processes that occur inside them and the interaction between their cytosolic components (and their subcellular location) and cells with their environment.

Essential concepts in cell biology

Illustration of the division of a cell. Source: pixabay.com

Entering the field of cell biology is a simple task when taking into account some basic knowledge or essential concepts, since with these and with the use of reason it is possible to understand in depth the complex world of cells.

Cells

Scheme of the two types of cells in nature: eukaryotic and prokaryotic. The main parts are shown, showing the differences between them (Source: No machine-readable author provided. Mortadelo2005 assumed (based on copyright claims). Via Wikimedia Commons)

Among the fundamental concepts that must be taken into account in the panorama is the conception that cells are the basic units of life, that is, that they are the "blocks" that allow the construction of organisms that we can call "living" and that all they are separated from the extracellular environment thanks to the presence of a membrane.

Regardless of their size, shape or function in a specific tissue, all cells carry out the same basic functions that characterize living things: they grow, feed, interact with the environment, and reproduce.

DNA

DNA molecule. Source: wikipedia.org

Although there are eukaryotic cells and prokaryotic cells, which are fundamentally different with respect to their cytosolic organization, whatever cell one has in mind, all, without exception, have deoxyribonucleic acid (DNA) inside them, a molecule that houses " the structural, morphological and functional planes ”of a cell.

Cytosol

Diagram of an animal cell and its parts. The cytosol is named at the bottom. (Source: Alejandro Porto via Wikimedia Commons)

Eukaryotic cells have specialized organelles in their cytosol for different functions that contribute to their vital processes. These organelles carry out energy production from nutrient material, the synthesis, packaging and transport of many cellular proteins, and also the import and digestion of large particles.

Cytoskeleton

Cells have an internal cytoskeleton that maintains shape, directs the movement and transport of proteins and the organelles that use them, as well as assisting in the movement or displacement of the entire cell.

Unicellular and multicellular organisms

There are unicellular and multicellular organisms (whose number of cells is highly variable). Cell biology studies usually focus on "model" organisms, which have been defined according to the type of cell (prokaryotes or eukaryotes) and according to the type of organism (bacteria, animal or plant).

The genes

Genes are part of the information encoded in DNA molecules that are present in all cells on earth.

These not only fulfill functions in the storage and transport of the information necessary to determine the sequence of a protein, but also exert important regulatory and structural functions.

Cell Biology Applications

There are a large number of applications for cell biology in fields such as medicine, biotechnology, and the environment. Here are some applications:

Fluorescent in situ staining and hybridization (FISH) of chromosomes can detect chromosomal translocations in cancer cells.

The technology of the microarrays of DNA "chip" allows to know the control of the gene expression of yeast, during its growth. This technology has been used to understand the expression of human genes in different tissues and cancer cells.

Fluorescence-labeled antibodies, specific against intermediate filament proteins, make it possible to know the tissue from which a tumor originated. This information helps the doctor choose the most appropriate treatment to fight the tumor.

Use of green fluorescent protein (GFP) to localize cells within a tissue. Using recombinant DNA technology, the GFP gene is introduced into specific cells of a complete animal.

Recent Research Examples in Cell Biology

Two examples of articles published in the journal Nature Cell Biology Review were chosen. These are the following:

Role of epigenetic inheritance in animals (Pérez and Ben Lehner, 2019)

It has been discovered that other molecules, in addition to the genome sequence, can transfer information between generations. This information can be modified by the physiological and environmental conditions of previous generations.

Thus, there is information in the DNA not associated with the sequence (covalent modifications of histones, DNA methylation, small RNAs) and information independent of the genome (microbiome).

In mammals, malnutrition or good nutrition affects the glucose metabolism of the offspring. Paternal effects are not always mediated by gametes, but they could act indirectly through the mother.

Bacteria can be inherited through the mother through the birth canal, or through breastfeeding. In mice, a diet low in fiber produces a decrease in the taxonomic diversity of the microbiome over generations. Eventually, the extinction of subpopulations of microorganisms occurs.

Chromatin regulation and cancer therapy (Valencia and Kadoch, 2019)

Currently, the mechanisms that govern the structure of chromatin and its role in disease are known. In this process, the development of techniques that allow identifying the expression of oncogenic genes and the discovery of therapeutic targets has been key.

Some of the techniques used are chromatin immunoprecipitation followed by sequencing (ChIP-seq), RNA sequencing (RNA-seq), chromatin transpoaccessible assay using sequencing (ATAC-seq).

In the future, the use of CRISPR – Cas9 technology and RNA interference will play a role in the development of cancer therapies.

References

1. Alberts, B., Bray, D., Hopkin, K., Johnson, AD, Lewis, J., Raff, M.,… & Walter, P. (2013). Essential Cell Biology. Garland Science.
2. Bolsaver, SR, Shephard, EA, White, HA, & Hyams, JS (2011). Cell Biology: a short course. John Wiley & Sons.
3. Cooper, GM, & Hausman, RE (2004). The cell: Molecular approach. Medicinska naklada.
4. Lodish, H., Berk, A., Zipursky, SL, Matsudaira, P., Baltimore, D., & Darnell, J. (2000). Molecular cell biology 4th edition. National Center for Biotechnology Information, Bookshelf.
5. Solomon, EP, Berg, LR, & Martin, DW (2011). Biology (9th ed.). Brooks / Cole, Cengage Learning: USA.