Definitions

Adhesion receptor (Integrin) - Binds molecules in extracellular matrix, changes conformation, thus altering interaction with cytoskeleton.

Allophagosomes - They are specialized vesicles involved in a cellular process called "allophagy." Allophagy is a selective form of autophagy, which is the cellular process responsible for the degradation and recycling of cellular components, including organelles (especially peroxisomes), proteins, and other cellular structures.

Archaebacteria or Archaea - one of the oldest form  bacteria, generally extremophilic in nature, they evolved independent of organisms of domain Bacteria

Amino acids - They are organic compounds that combine to form proteins, they serve as the building blocks of the living system. They are necessary for the growth and development, in nature 300 amino acids found to exist. 

Anaphase - a stage in mitosis where chromosomes begin moving to opposite ends (poles) of the cell.

Animal Cells - eukaryotic cells that contain various membrane-bound organelles.

Allele - an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome.

Apoptosis - a controlled sequence of steps in which cells signal self-termination.

Aromatic amino acids - Amino acids that have an aromatic ring (phenylalanine, tryptophan and tyrosine) are called aromatic amino acids. These aromatic amino acids are used to make hormones and various amines in the body. 

Asters - radial microtubule arrays found in animal cells that help to manipulate chromosomes during cell division.

Autoinducers - Signal molecules that contribute to the regulation of the expression of particular genes. e.g. acyl homoserine lactone.

Autophagosomes - These vesicles are involved in autophagy, a process in which the cell degrades its own components, including damaged organelles and proteins.

Biomolecules - They are the organic molecules produced by a cells, involved in maintenance and metabolic processes of living organisms, they are esssential structural and functional components of life. e.g. Proteins, carbohydrates, lipids and nucleic acids. 

Cell - the fundamental unit of life.

Cellular Respiration - a process by which cells harvest the energy stored in food.

Cell Biology - the subdiscipline of biology that focuses on the study of the basic unit of life, the cell.

Cell Cycle - the life cycle of a dividing cell, including Interphase and the M phase or Mitotic phase (mitosis and cytokinesis).

Cellulose - is a plant polymeric molecule comprises of hundreds to thousands of glucose units, it provide strength to the plant cells. 

Cell membrane - a thin semi-permeable membrane that surrounds the cytoplasm of a cell.

Cell theory - one of the five basic principles of biology, stating that the cell is the basic unit of life.

Centrioles - cylindrical structures that are composed of groupings of microtubules arranged in a 9 + 3 pattern.

Centromere - a region on a chromosome that joins two sister chromatids.

Chaperones - they are specialized form of proteins that assist in proper folding of other proteins, ensuing they achieve proper 3D conformation.

Chitin - a cell wall polymer of insects and fungi made up of n-acetyl glucosamine monomeric units.

Cell Cycle - refers to series of events that take place in a eukaryotic cell during interphase that leads to duplication and division of its DNA (Mitosis) and cytoplasm (cytokinesis) and distribution of organelles to produce two daughter cells. 

Check points of cell cycle - refers to control mechanisms operative during interphase in eukaryotic cells which ensure proper division of the cell. 

Chromatid - one of two identical copies of a replicated chromosome.

Chromatin - the mass of genetic material composed of DNA and proteins that condense to form chromosomes during eukaryotic cell division. It is divided between heterochromatin (condensed & genetically less expressed) and euchromatin (extended & genetically highly expressed) forms. 

Chromosome - a long, stringy aggregate of genes that carries heredity information (DNA) and is formed from condensed chromatin.

Cilia and Flagella - protrusions from some cells that aid in cellular locomotion.

Collagen - It is a protein that makes up skin, ligaments and cartilage. Roughly one-third of the protein in the body is collagen. It is made from the amino acids alanine and proline 

Cristae - inner membrane of the mitochondria gets folded on itself to increase the surface area for biochemical reactions like electron transport chain functioning.

Cytochrome - They are redox-active proteins containing a heme, with a central Fe atom at its core, as a cofactor. They are involved in electron transport chain and redox catalysis. 

Cytokinesis - the division of the cytoplasm that produces distinct daughter cells.

Cytokines - are a large group of proteins, peptides or glycoproteins that are secreted by specific cells of immune system. They are a category of signaling molecules that mediate and regulate immunity, inflammation and hematopoiesis. 

Cytoplasm - all of the contents outside of the nucleus and enclosed within the cell membrane of a cell.

Cytoskeleton - a network of fibers throughout the cell's cytoplasm that helps the cell maintain its shape and gives support to the cell.

Cytosol - semi-fluid component of a cell's cytoplasm.

Daughter Cell - a cell resulting from the replication and division of a single parent cell.

Daughter Chromosome - a chromosome that results from the separation of sister chromatids during cell division.

Dynein - Dynein motor proteins move vesicles toward the cell's center, using ATP as energy, often returning them to the MTOC, and are also involved in the transport of cargo within the axon of neurons. 

Diploid Cell - a cell that contains two sets of chromosomes—one set of chromosomes is donated from each parent.

Electron transport chain - is a cluster of proteins that transfer electrons through a membrane within mitochondria (eukaryotes) or cytoplasmic membrane (prokaryotes) to form a gradient of protons that drives the creation of adenosine triphosphate (ATP). 

Endoplasmic Reticulum - a network of tubules and flattened sacs that serve a variety of functions in the cell.

Enzymes - Commonly made of proteins that speed up reactions (biological catalysts) to turn certain substances into other substances. e.g. Lipase, Protease. . 

Ergosterol - A kind of sterol that resides on the cell membranes of fungi and acts to maintain cell membrane integrity, similar to mammalian cholesterol 

Fo/F1 particles - they are ATPase enzyme involved in the ATP production, present in the cristae of mitochondria. They are also called as oxysomes.  

Gametes - reproductive cells that unite during sexual reproduction to form a new cell called a zygote.

Gene Theory - one of the five basic principles of biology, stating that traits are inherited through gene transmission.

Genes - segments of DNA located on chromosomes that exist in alternative forms called alleles.

Glutathione - It is a peptide (short chain of amino acids) made from glutamate, cysteine and glycine. Glutathione protects the body from oxidants and promotes the normal function of immune cells 

Golgi Complex - the cell organelle that is responsible for manufacturing, warehousing, and shipping certain cellular products.

G protein coupled receptor (GPCRs) are a large family of cell surface receptors that respond to a variety of external signals. Binding of a signaling molecule to a GPCR results in G protein activation, which in turn triggers the production of any number of second messengers. Also called as Serpentine receptors.

Grana - Stacks of thylakoid discs present in the chloroplast, they are they seat for oxygenic photosynthesis and photophosphorylation.    

Haploid Cell - a cell that contains one complete set of chromosomes.

Hopanoid - they are diverse group of pentacyclic triterpenoid lipids mainly produced by bacteria, analogues to cholesterol, involved in maintaining membrane fluidity.  

Keratin - It is a protein that is plentiful in hair, nails and skin and helps to protect the body. Keratin is rich in sulfur-containing amino acids such as methionine. 

Kinesin - Kinesin  is a motor proteins that move vesicles toward the cell's periphery, on the expense of hydrolysis of ATP,  typically using microtubules as platform, which extend from the microtubule organizing center (MTOC) near the nucleus to the cell's periphery. 

Ligands - also called as signal molecules, that binds to cell surface receptors or can pass into cell membrane and bound intracellular receptors.

Ligand gated Ion channel receptors - Ligand-gated ion channels bind neurotransmitters and open in response to ligand binding. These channels control synaptic transmission between two neurons or between a neuron and a muscle.

Interphase - the stage in the cell cycle where a cell doubles in size and synthesizes DNA in preparation for cell division.

Lipids - They are a diverse group of hydrophobic or amphipathic molecules includes fats, oils, waxes, certain vitamins, hormones, and most of the non-protein membrane components of cells. They play a variety of roles in the body, including energy storage, structural components of cell membranes, and signaling molecules 

Liposomes are artificial spherical bilayers that are used in research for study of both membrane lipids and integral membrane proteins. They are also used to deliver drugs and other macromolecules into cells for either research or therapeutic purposes.  

Lysosomes - the membranous sacs of enzymes that can digest cellular macromolecules.

Meiosis - a two-part cell division process in organisms that sexually reproduce, resulting in gametes with one-half the number of chromosomes of the parent cell.

Metaphase - the stage in cell division where chromosomes align along the metaphase plate in the center of the cell.

Microtubules - fibrous, hollow rods that function primarily to help support and shape the cell.

Mitochondria - cell organelles that convert energy into forms that are usable by the cell.

Mitosis - a phase of the cell cycle that involves the separation of nuclear chromosomes followed by cytokinesis.

N-acyl homoserine lactones -They are a class of signaling molecules involved in bacterial quorum sensing. 

Nucleic acids - They  are large biomolecules essential for all known forms of life. They are the carriers of genetic information and are responsible for the storage, transmission, and expression of genetic instructions. e.g. DNA and RNA.

Nucleus - a membrane-bound structure that contains the cell's hereditary information and controls the cell's growth and reproduction.

Nucleosome - A nucleosome is the basic structural repeating subunit of chromatin packaged inside the cell's nucleus of eukaryotes. In humans, about six feet of DNA must be packaged into a nucleus with a diameter less than a human hair, and nucleosomes play a key role in that process. 

Nuclear membrane - a double walled membrane that encloses the cell nucleus (in eukaryotes) and separate it from rest of the cytoplasm, also called as nuclear envelope. 

Nuclear pores - They are protein-lined channel in the nuclear envelope or nuclear membrane that regulates the transportation of molecules between the nucleus and the cytoplasm. 

Organelles - tiny cellular structures, that carry out specific functions necessary for normal cellular operation.

Oxidative phosphorylation – a phosphorylation process (addition of inorganic PO4 to ADP) takes place during the oxidation of electron donor during cellular respiration. 

Oxidative burst - Phagocytes, like neutrophils, can also generate reactive oxygen species (ROS) during phagocytosis. This oxidative burst helps to kill and digest engulfed pathogens. 

Peroxisomes - cell structures that contain enzymes that produce hydrogen peroxide as a by-product.

Phagocytosis - process by which certain living cells called phagocytes ingest or engulf other cells or particles. The phagocyte may be a free-living one-celled organism, such as an amoeba, or one of the body cells, such as a white blood cell. 

Phospholipids - they are essential for making cell membranes. Phospholipids are abundant in cells and blood. Eggs and soy are foods with lots of phospholipids. 

Photophosphorylation - a phosphorylation process (addition of inorganic PO4 to ADP) takes place during photosynthesis when the electron (obtained from H2O) is transferred through electron carrier and photosystems  finally leads to NADPH synthesis and proton gradient formation.

Plant Cells - eukaryotic cells that contain various membrane-bound organelles. They are distinct from animal cells, containing various structures not found in animal cells.

Polar Fibers - spindle fibers that extend from the two poles of a dividing cell.

Prokaryotes - single-celled organisms that are the earliest and most primitive forms of life on earth.

Prophase - the stage in cell division where chromatin condenses into discrete chromosomes.

Protein structure - Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached in long chains. The sequence of amino acids determines each protein’s unique 3D structure and its specific function. They are essential for the structure, function, and regulation of the body's tissues and organs.  The various level of protein structure organized in the cells include Primary structure, secondary structure, tertiary structure and quatenary structure. 

Protoplasm theory - Protoplasm is the physical basis of life.

Quorum sensing - It is a process of cell–cell communication that allows bacteria to share information about cell density and adjust gene expression accordingly. They are also defined as  density dependent sensing of bacteria, the regulation of gene expression in response to fluctuations in cell-population density. 

Ribosomes - cell organelles that are responsible for assembling proteins.

Receptors - Refers to  proteins, usually present in cell surface, which bind to ligands (signals) and cause responses.

Receptor enzymes - An enzyme-linked receptor, also known as a catalytic receptor, is a transmembrane receptor, where the binding of an extracellular ligand causes enzymatic activity on the intracellular side.

Receptor-mediated endocytosis - It is a highly specific and regulated process by which cells internalize specific molecules from their external environment. It plays a crucial role in various cellular functions, including the uptake of essential nutrients (e.g. cholesterol transport and release in the cells), regulation of signalling pathways, and the removal of certain molecules from the extracellular fluid.

Receptor tyrosine kinases (RTK) - They are high affinity cell surface receptors belong to subclass of tyrosine kinases. It mediates cell to cell communication. They are high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones, they belonging to subclass of tyrosine kinases. They are involved in mediating cell-to-cell communication and controlling a wide range of complex biological functions, including cell growth, motility, differentiation and metabolism. 

Receptor guanylyl cyclase - In this receptor the ligand is binding to the extracellular domain, stimulates formation of second messengers like cyclic GMP.

Second messengers - Short lived molecules that relay signals from the receptors on the cell surface to target molecules, greatly amplify the strength of the signal e.g. cyclic AMP

Signal transduction pathway - it refers to sequence of molecular events and chemical reactions that lead to a cell’s response to a signal.

Signal amplification - A process by which the initially received signal intensity is increased or amplified through networks of intracellular reactions.

Sister Chromatids - two identical copies of a single chromosome that are connected by a centromere.

Spindle Fibers - aggregates of microtubules that move chromosomes during cell division.

Stroma - matrix region of the chloroplast, contains enzymes and other essential molecules required for C fixation. 

Substrate phosphorylation - a phosphorylation process (addition of inorganic P to ADP) takes place during the oxidation of substrates during glycolysis or citric acid cycle operation or fermentation process.

Telophase - the stage in cell division when the nucleus of one cell is divided equally into two nuclei.

Thylakoids - They are internal membrane bound compartments inside chloroplast and they are the site for light dependent photosynthetic reactions (photophosphorylation). 

Vesicles - Vesicles are small, membrane-bound sacs within cells that play a crucial role in intracellular transport, maintaining the compartmentalization of cellular components, and facilitating communication between different organelles. 

References and Courtesy

Bailey, R. "Cell Biology Glossary." ThoughtCo, Aug. 25, 2020, https://www.thoughtco.com/cell-biology-glossary-373293. 

Wong E.V. "Cells: Molecules and Mechanisms", Axolotl Academica Publishing, Libre Texts, assessed on 10-09-2023.

And VSS manually curated from the Internet, Artificial intelligence (AI) sources including Chat GPT and Gemini.