cytoplasm

Typical plant and animal cell. Plant and animal cells share many structures, such as ribosomes, mitochondria, and chromosomes, but they also have notable differences: plant cells have chloroplasts, a large vacuole, and a cellulose cell wall. Animal cells do not have a rigid cell wall but have an outside cell membrane only.

Part of plant and animal cells outside the nucleus (and outside the large vacuole of plant cells). Strictly speaking, this includes all the organelles (mitochondria, chloroplasts, and so on) and is the area in which most cell activities take place. However, cytoplasm is often used to refer to the jellylike matter in which the organelles are embedded (correctly termed the cytosol). Most of the activities in the cytoplasm are chemical reactions (metabolism), for example, protein synthesis.

In many cells, the cytoplasm is made up of two parts: the ectoplasm (or plasmagel), a dense gelatinous outer layer concerned with cell movement, and the endoplasm (or plasmasol), a more fluid inner part where most of the organelles are found.