What Are Cells?

What are cells?

Cells are classified as either Prokaryotic or Eukaryotic.The Cell Theory was the first unifying theory of Biology:1.Cells are the fundamental units of life2.All organisms are composed of cells3.All cells come from preexisting cells

Most cells are tiny, in order to maintain a good surface area-to-volume ratio.The volume of a cell determines its metabolic activity per unit of time.The surface area of a cell determines the amount of substances that can enter or leave the cell.

Prokaryotes have no membrane-enclosed compartments.• Eukaryotes have membrane-enclosed compartments called organelles, such as the nucleus.

Prokaryotic cells:• Are enclosed by a cell membrane• Have DNA located in the nucleoid regionThe rest of the cytoplasm consists of:• Cytosol (water and dissolved material)and suspended particles• Ribosomes—sites of protein synthesis