• The smallest unit of life Molecules move from area of higher concentration to lower concentration • Cells without a nucleus and membrane bound organelles • bacteria Which molecule in the cell membrane? • • • • • Maintains fluidity Barrier to polar, large, and charged molecules Identifies the cell Channel Attachment site for cytoskeleton Which organelle? • • • • • • • • • Breaks things down and recycles them Makes proteins Makes energy Photosynthesis Processes and packages Fluid of cell Control center Makes ribosomes Stores water and is large in the plant cell • Water molecules moving across a membrane from an area of higher water concentration to lower water concentration • Large (bulk) materials are leaving the cell via a vesicle • What are the 2 kinds of cell transport? What is the difference between them? • A structure inside a cell that performs a specific function • Some things can pass through but others can not • Molecules moving down their concentration gradient with the help of a carrier or channel protein