The basic components of a human cell are the cell membrane, the cytoplasm, the nuclear membrane and the nucleus. Within each of these parts are smaller structures, such as the organelles, which have specialized functions within the cell.
The human body is made up of roughly 10 trillion cells, each held together by a cell membrane. The cell membrane is semi-permeable, with various protein molecules allowing substances in and out of the cell. It completely surrounds the cell, protecting all the organelles inside. The cytoplasm is the jelly-like substance inside that keeps the organelles in place.
The nuclear membrane separates the nucleus from the rest of the cell. It has nuclear pores that allow nutrients into the nucleus and carry waste out. The nucleolus governs the cell organelles, such as the lysosomes that help absorb nutrients, the ribosomes that synthesize proteins and remove waste and the mitochondria that produce adenosine triphosphate, or ATP. The latter is a form of energy used by the cell.
The nucleus is the heart of the cell, containing the DNA and the 46 chromosomes needed to be human. Each parent contributes 23 chromosomes, which passes down certain familial traits. All cells in the human body have the 46 chromosomes, except for the sex cells. The unfertilized eggs and sperm cells each have 23. When fertilization occurs, the magic number of 46 is reached.