Saturday, April 11, 2015

What is an organelle?

Organelles are tiny organs within each cell. Each organelle has a specific structure and function for keeping the cell in a homeostatic state. Plant and animal cells, even though alike in many ways, have a few organelle differences. Prokaryotes and Eukaryotes differ in that prokaryotes have hardly any organelles.


Animal cells have the following organelles:


nucleus - houses the nucleolus, DNA and RNA. It is surrounded by a nuclear membrane that is selectively permeable.


lysosome - this is referred to as a 'suicide sac' because it holds digestive enzymes that aid in recycling waste materials in the cells


vacuole - this houses water and nutrients for the cell


mitochondria - this is commonly referred to as the 'power house' of the cell due to it's ability to break down sugar in order to release energy for cell function. Mitochondrial DNA is housed here.


endoplasmic reticulum - this is a series of tunnel like structures that aid in transportation and ribosome production. There are two types: smooth ER (no ribosomes) and rough ER (ribosomes)


golgi - these organelles package and distribute proteins throughout the cell


ribosomes - these organelles are responsible for protein assemblage. They receive their assembly information from DNA in the nucleus.


The organelles sit in cytoplasm which is a thick nutrient broth in the cell. The cell is surrounded by a membrane that is semi-permeable.


The cell keeps its structure through a series of structures called the cytoskeleton, which also act as a transportation system.


Plant cells have the addition of chloroplasts which are pigmented organelles that aid in photosynthesis. They also have an outer cell wall, made of cellulose, encasing the cell membrane. Their vacuoles are much larger than those found in animal cells.

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