Electron Microscopy in Cellular Biology

Electron Microscopy (E.M.) Images of Cellular Structures

• Smooth Endoplasmic Reticulum (SER): Shows a network of interconnected, flattened sacs and tubules, lacking ribosomes.
• Rough Endoplasmic Reticulum (rER): Displays a network of flattened sacs studded with ribosomes. The ribosomes are prominent features. This structure is different from SER.
• Mitochondria: Elliptical organelles with inner folded membranes (cristae). A scale of 0.5 µm is displayed, indicating size.
• Cell Membrane: A bilayer structure seen as a thin line with a somewhat granular or fuzzy appearance.
• Cilia: Ring-shaped arrangement of microtubules. Shown with an electron micrograph.
• Centriole: Circular arrangement of microtubules, a component of the microtubule organizing center.
• Golgi Apparatus: A stack of flattened sacs with associated vesicles.
• Free Ribosomes: Clusters of granular ribosomal structures that are not attached to the endoplasmic reticulum.
• Free & Attached Ribosomes: Shown in a micrograph, revealing both free and attached ribosomes, exhibiting differing appearances and locations. The attached ones are associated with ER.
• Lysosomes: Membrane-bound organelles appearing as spherical structures with an internal granular content, visible using electron microscopy.
• Euchromatic Nucleus: Sparsely stained, less condensed chromatin in the nucleus, displaying a less dense appearance in the EM image. The scale is 500 nm.
• Heterochromatic Nucleus: Densely stained, highly condensed chromatin in the nucleus, seen with a darker, more compact appearance in the electron micrograph.
• Proxisomes: Small, round, membrane-enclosed organelles, with a homogenous interior.

This quiz explores various cellular structures visualized through electron microscopy. Key organelles, such as the smooth and rough endoplasmic reticulum, mitochondria, and Golgi apparatus, are examined in detail. Test your knowledge on the appearance and functions of these vital components.