Organelles are structures within a cell that have specific functions; membrane-bound organelles are organelles protected by a single or double plasma membrane. Mitochondria, lysosomes, the endoplasmic reticulum and the G... More »

Cellular walls, nuclei, vacuole and lysosomes are all examples of cellular organelles. Organelles are broadly classified as either mitochondria or plastids, depending on whether or not they contain DNA. Within a cell, ea... More » Science Biology Cells

One purpose that membrane-bound organelles serve is to allow the isolation and concentration of enzymes and reactants within a small space. This enables chemical reactions in a cell to occur faster and with greater effic... More »

Eukaryotic cells have organelles, membrane-bound structures that perform different functions in the cell, and prokaryotic cells do not. Some typical eukaryotic organelles include the nucleus, mitochondria, ribosomes, Gol... More »

The primary reason that scientists and students stain onion cells is to make it easier to discern the various structures and organelles. In practice, most cells are treated with stains or dyes to give them higher contras... More »

Vacuoles are the large, sac-like organelles that are used for storage and other functions within the cell. They are similar to, but distinct from, the vesicles, which are tiny sacs that help transport chemicals within th... More »

Human epithelial cells, which are animal cells, and elodea cells, which are plant cells, share many structures because both are eukaryotic cells, or cells with a membrane-bound nucleus. Common structures in animal and pl... More »