Use what you've learned this week to answer the essential question: " How do the parts of a cell function to keep the cell alive? " Your answer can be posted to Google Classroom, and should use evidence from this week's learning activities to support your claim.

Cell Structure

Bacterial Cells A simple bacterial cell has some parts that are common to all cells. It has a cell membrane that protects the cell and controls what substances enter and leave the cell. It has DNA, the instructions for carrying out cell functions. It also has cytoplasm and ribosomes.

Animal Cells Animal cells have some additional parts that bacterial cells don't have. Animal cells, and many other cells store DNA in a nucleus. They also have some other organelles, such as mitochondria, endoplasmic reticulum (ER), Golgi apparatus, lysosomes, and vacuoles.

Plant Cells Plant cells have three additional structures that animal cells do not. Chloroplasts use the sun's energy to make sugar. A cell wall protects and supports a plant cell and regulates the amount of water in the cell. The central vacuole stores water and other liquid materials. It also works with the cell wall to maintain the cell's shape.

Transport through the Cell Membrane The cell membrane controls what enters and exits the cell. Some things can enter and exit without energy by diffusion or facilitated diffusion. Energy is required when membrane proteins carry particles from lower concentration to higher concentration. Energy is also needed for endocytosis or exocytosis, in which large particles are moved by folding the cell membrane around them.

Cells Must Be Small Cells must be small so that the cell membrane can take in the materials the cells need and remove wastes.