What are the main structures of an animal cell, and what are their functions?

The main structures in an animal cell are: The cell membrane- the membrane found around the outside of the cell, some substances can cross it to move in and out of the cell (this means it is semi-permeable). The cytoplasm- a jelly-like material found inside the cell membrane, which contains nutrients and the other structures (which are called organelles). The nucleus- the structure found in cells, which contains the cell's DNA and can control the cell's activities. The mitochondria- the 'powerhouse' of the cells, they contain enzymes that are involved in respiration, which releases energy for the cell to use. The ribosomes- structures found in the cell, where protein synthesis (making new proteins) happens.