Parts of cell structure and functions

• Mitochondria generate the cell's supply of adenosine triphosphate (ATP), which is the chemical energy currency of cells.
• Lysosomes contain digestive enzymes that break down waste materials within the cell.
• Ribosomes are responsible for protein synthesis through translation of mRNA into amino acid sequences.
• The endoplasmic reticulum (ER) is involved in protein synthesis, lipid metabolism, calcium storage, and detoxification processes.
• Ribosomes are responsible for protein synthesis.
• Microorganisms, also known as microbes, are microscopic organisms that exist as unicellular, multicellular, or cell clusters.
• Microorganisms are divided into seven types: bacteria, archaea, protozoa, algae, fungi, viruses, and multicellular animal parasites (helminths).
• Each type of microorganism has a characteristic cellular composition, morphology, mode of locomotion, and reproduction.
• Microorganisms are beneficial in producing oxygen, decomposing organic material, providing nutrients for plants, and maintaining human health, but some can be pathogenic and cause diseases in plants and humans.
• Microorganisms are widespread in nature and are beneficial to life, but some can cause serious harm.
• Microorganisms can be divided into six major types: bacteria, archaea, fungi, protozoa, algae, and viruses.
• Bacteria are unicellular organisms with prokaryotic cells that exist in four major shapes: bacillus (rod shape), coccus (spherical shape), spirilla (spiral shape), and vibrio (curved shape).
• Most bacteria have a peptidoglycan cell wall; they divide by binary fission; and they may possess flagella for motility.
• The difference in their cell wall structure is a major feature used in classifying these organisms.
• According to the way they obtain energy, bacteria are classified as heterotrophs or autotrophs.
• Autotrophs make their own food by using the energy of sunlight or chemical reactions, in which case they are called chemoautotrophs.
• Heterotrophs obtain their energy by consuming other organisms.
• Bacteria that use decaying life forms as a source of energy are called saprophytes.
• Archaea or Archaebacteria differ from true bacteria in their cell wall structure and lack peptidoglycans.
• Archaeans are prokaryotic cells with avidity to extreme environmental conditions.
• All Archaeans can be divided into the following groups: methanogens (methane-producing organisms), halophiles (archaeans that live in salty environments), thermophiles (archaeans that live at extremely hot temperatures), and psychrophiles (cold-temperature Archaeans).
• Protozoa make up the largest group of organisms in the world in terms of numbers, biomass, and diversity.
• Archaeans use different energy sources like hydrogen gas, carbon dioxide, and sulphur.
• The cell walls of protozoa are made up of cellulose.
• Viruses are noncellular entities that consist of a nucleic acid core (DNA or RNA) surrounded by a protein coat.
• Algae, also called cyanobacteria or blue-green algae, are unicellular or multicellular eukaryotes that obtain nourishment by photosynthesis.
• Viruses are classified as microorganisms, but are not considered living organisms.
• Fungi form characteristic filamentous tubes called hyphae that help absorb material.
• Fungi reproduce by releasing spores.
• The collection of hyphae is called mycelium.
• Fungi are eukaryotic cells with a true nucleus and their cell wall is composed of chitin.
• Protozoa have been traditionally divided based on their mode of locomotion: flagellates produce their own food and use their whip-like structure to propel forward, ciliates have tiny hair that beat to produce movement, amoeboids have false feet or pseudopodia used for feeding and locomotion, and sporozoans are non-motile.
• Algae live in water, damp soil, and rocks and produce oxygen and carbohydrates used by other organisms.
• Parasitic helminths are of clinical importance and are often discussed along with the other groups of microbes.
• A group of eukaryotic organisms consisting of the flatworms and roundworms, which are collectively referred to as the helminths.
• Cyanobacteria are the origins of green land plants.
• Viruses cannot reproduce outside a host cell and cannot metabolize on their own.
• Protozoa are unicellular aerobic eukaryotes with a nucleus, complex organelles, and obtain nourishment by absorption or ingestion through specialized structures.
• Helminths are not microorganisms by definition, since they are large enough to be easily seen with the naked eye, they live a part of their life cycle in microscopic form.
• Fungi obtain nutrients by absorbing organic material from their environment, through symbiotic relationships with plants, or harmful relationships with a host.