Cell including the key components and their functions.

Your notes provide a detailed diagram of a cell, labeling various organelles such as the nucleus, mitochondria, ribosomes, and endoplasmic reticulum. The notes also clearly define the function of the cell membrane.

The cell membrane is described as a semi-permeable barrier that surrounds the cell. Its primary function is to control the movement of substances into and out of the cell, which is crucial for maintaining homeostasis.