Microbial Minds

Key Points to Remember Viroids are tiny, circular RNA molecules. They infect plants only and lack a protein coat. They do not code for proteins but still replicate inside plant cells. They cause major crop diseases, spreading through tools, seeds, or pollen. Managed through field hygiene, disease-free seeds, and monitoring. Keywords Viroid, Circular RNA, Plant Disease, RNA Replication, Potato Spindle Tuber Viroid (PSTVd), Non-coding RNA. Viroids – The Simplest Infectious Agents Viroids are the smallest known infectious agents, made up of only a short, circular strand of RNA. Unlike viruses, they do not have a protein coat and cannot make proteins. They infect only plants, but even with their tiny size, they can cause serious plant diseases that reduce crop yield and affect global agriculture. Definition Viroids are small, circular, single-stranded RNA molecules that can replicate independently inside plant cells. Size: Usually between 250–400 nu...

  Plasmids Summary Plasmids are small, free DNA molecules, mostly occurred in prokaryotes. They are essential for microbial adaptation, gene transfer, and antibiotic resistance. Plasmids are essential to biotechnology for cloning, gene therapy, and vaccine manufacturing. Addressing issues related to global health and the environment requires an understanding of plasmid biology. Keywords Plasmid, DNA, Bacteria, Prokaryotes, Eukaryotes, Circular DNA, Double-stranded DNA, Origin of replication (ori), Copy number, Horizontal gene transfer, Antibiotic resistance. Definition Small, circular, double-stranded DNA molecules called plasmids occur in cells apart from the chromosomes. Although they are most frequently found in bacteria, they may also be found in some eukaryotic creatures and archaea. Plasmids, in contrast to the bacterial chromosome, can confer selection benefits like antibiotic resistance but are not necessary for the host's survival in typical circumstances...

Summary Ribosomes are universal, non-membranous, ribonucleoprotein particles responsible for protein synthesis. They translate genetic code from mRNA into amino acid chains (polypeptides). Found as free ribosomes in the cytoplasm or bound to the rough endoplasmic reticulum (ER) in eukaryotic cells. Made up of two subunits (large and small), each containing rRNA and proteins. Crucial for gene expression, growth, cell maintenance, and development. Keywords Ribosome, protein synthesis, translation, rRNA, mRNA, tRNA, subunits, 70S ribosome, 80S ribosome, peptidyl transferase, gene expression, polyribosome. Ribosomes: The Protein Factories of the Cell The ribosome is one of the most essential structures in all living cells. Despite its tiny size, it performs one of life’s most critical tasks — protein synthesis. These non-membranous organelles act as the protein factories of the cell, translating genetic information from mRNA into func...

Summary The cytoplasm is the main site for most biological and metabolic reactions. It includes three major parts: cytosol (fluid portion), organelles (functional units), and inclusions (storage materials). It maintains the internal balance, supports cell communication, and aids in movement. In eukaryotes, the cytoplasm surrounds but excludes the nucleus; in prokaryotes, it contains all internal contents. Keywords Cytoplasm, cytosol, organelles, inclusions, cytoskeleton, cytoplasmic streaming, metabolism, cell structure, prokaryotes, eukaryotes. Cytoplasm: The Dynamic Matrix of Life Introduction The cytoplasm is one of the most vital components of every living cell. Acting as a gel-like matrix, it fills the space between the cell membrane and the nucleus (in eukaryotic cells). It provides a supportive environment where essential biochemical reactions, growth, transport, and cell signaling occur. Whether in prokaryotic or eukaryotic c...