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Take a Tour of Your Cells’ Organelles!

Imagine you’ve shrunk down to about 3 millionths of your normal size. You are now about 0.5 micrometers tall (a micrometer is 1/1,000th of a millimeter). At this scale, a medium-sized human cell looks as long, high, and wide as a football field. But you can’t see nearly that far. Clogging your view is a rich stew of molecules, fibers, and various cell structures called organelles. Like the internal organs in your body, organelles in the cell each have a unique biological role to play.

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 Scientists Discover Unknown Organelle Inside Our Cells

The discovery of an unknown organelle inside our cells could open the door to new treatments for devastating inherited diseases. The organelle, a type of specialized structure, has been dubbed a “hemifusome” by its discoverers at the University of Virginia School of Medicine and the National Institutes of Health. This little organelle has a big job helping our cells sort, recycle and discard important cargo within themselves, the scientists say. The new discovery could help scientists better understand what goes wrong in genetic conditions that disrupt these essential housekeeping functions. “This is like discovering a new recycling center inside the cell,” said researcher Seham Ebrahim, PhD, of UVA’s Department of Molecular Physiology and Biological Physics.

 Talking organelles: A riot of metaphors

The Oxford English Dictionary defines organelles as: “Any of various discrete, usually membrane-bound, structures within a cell or unicellular organism that perform specialized functions”. The term is first attested for 1915 but harks back to an earlier term organella/organula from 1889. Somebody writing in American Naturalist pointed out: “It may possibly be of advantage to use the word organula here instead of organ, following a suggestion by Möbius. Functionally differentiated multicellular aggregates in multicellular forms or metazoa are in this sense organs, while for functionally differentiated portions of unicellular organisms or for such differentiated portions of the unicellular germ-elements of metazoa the diminutive—organula—is appropriate.”

Articles of Interest

Biology Microscopy - Organelles

Some organelles are easily viewed with a light microscope.

Cell Organelles

Cells are the building blocks of life that can survive and function as single cellular organisms like bacteria or protists, or band together by the hundreds or trillions to make multicellular organisms like humans and other complex life. All of these cells must receive and respond to input from their environment, and each other, to maintain the fragile state of life. This vast cellular network of communication is mirrored within each cell as it efficiently creates and sends messages and materials around the interior of the cell.

Cell Organelles Dicoverers

. But have we wondered who discovered them? So, I just want to make it easy for you all by jotting down the organelles and their discoverers over here.

Cells have more mini ‘organs’ than researchers thought − unbound by membranes, these rogue organelles challenge biology’s fundamentals

Think back to that basic biology class you took in high school. You probably learned about organelles, those little “organs” inside cells that form compartments with individual functions. For example, mitochondria produce energy, lysosomes recycle waste and the nucleus stores DNA. Although each organelle has a different function, they are similar in that every one is wrapped up in a membrane. Membrane-bound organelles were the textbook standard of how scientists thought cells were organized until they realized in the mid-2000s that some organelles don’t need to be wrapped in a membrane. Since then, researchers have discovered many additional membraneless organelles that have significantly changed how biologists think about the chemistry and origins of life.

Cellular organelles

Organelles are considered either membranous or non-membranous. Membranous organelles possess their own plasma membrane to create a lumen separate from the cytoplasm. This may be the location of hormone synthesis or degradation of macromolecules. Non-membranous organelles are not surrounded by a plasma membrane. Most non-membranous organelles are part of the cytoskeleton, the major support structure of the cell. These include: filaments, microtubules, and centrioles.

Editorial overview: Cell organelles

Organelles compartmentalize cells, allowing the regulation of the numerous processes that occur within them. Early studies of cells using microscopy and fractionation revealed that organelles have characteristic sizes, shapes, compositions, and positions within cells. Later, as more advanced techniques were developed it became clear that organelles are also highly dynamic and that complex mechanisms are used to form and maintain organelles. C

Look, Ma! No Mitochondria

Scientists have found a microbe that does something textbooks say is impossible: It's a complex cell that survives without mitochondria. Mitochondria are the powerhouses inside eukaryotic cells, the type of complicated cell that makes up people, other critters and plants and fungi. All eukaryotic cells contain a nucleus and little organelles — and one of the most famous was the mitochondrion.

Mapping the Secret Lives of Human Cells

For its map, the Allen Institute team harnessed a workhorse of molecular biology, fluorescent proteins, to label and monitor organelles in human stem cells. For instance, they turned mitochondria—the powerhouses of cells—white. They scanned these cells thousands of times to get a comprehensive picture of how cells behave.

Organelles

Just as organs are separate body parts that perform certain functions in the human body, organelles are microscopic sub-units that perform specific functions within individual cells.

Sheets, ribbons and tubules — how organelles get their shape

Most membrane-bound organelles have elaborate, dynamic shapes and often include regions with distinct morphologies. These complex structures are relatively conserved throughout evolution, which indicates that they are important for optimal organelle function. Various mechanisms of determining organelle shape have been proposed — proteins that stabilize highly curved membranes, the tethering of organelles to other cellular components and the regulation of membrane fission and fusion might all contribute.

The functions of cell organelles

Cells are microscopic building blocks of unicellular and multicellular living organisms. Animal, plant, fungal and bacterial cells are different in terms of structure but also have many similarities.

Theory of Organelle Biogenesis: A Historical Perspective

Organelles, defined as intracellular membrane-bound structures in eukaryotic cells, were described from the early days of light microscopy and the development of cell theory in the 19th century. During the 20th century, electron microscopy and subcellular fractionation enabled the discovery of additional organelles and, together with radiolabelling, allowed the first modern experiments on their biogenesis.

These Super-Resolution Microscopes Are Revealing the Inner Lives of Cells

Advanced light microscopy techniques are giving scientists a new understanding of human biology and what goes wrong in diseases

What Is an Organelle?

An organelle is a tiny cellular structure that performs specific functions within a cell. Organelles are embedded within the cytoplasm of eukaryotic and prokaryotic cells. In the more complex eukaryotic cells, organelles are often enclosed by their own membrane. Analogous to the body's internal organs, organelles are specialized and perform valuable functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from generating energy for a cell to controlling the cell's growth and reproduction.

Whoa—Scientists Found a Part of Human Cells We Never Knew Existed

Back in high school biology, most of us learned about the innards of a cell, or its organelles, from ribosomes to mitochondria to the endoplasmic reticulum, and probably had to identify them on our midterms. Now, an unexpected discovery will probably soon rewrite those textbooks. The hemifusome is the new organelle that high school students (much to their chagrin) will have to remember.