3.5 Active Transport, Endocytosis, and Exocytosis KEY CONCEPT Cells use energy to transport materials that cannot diffuse across a membrane.

Which is active transport and which is passive transport and why? The waterfall is passive because no input of energy is required to move water; the pump is active because energy is needed to move water. Cells often need to gather ions and other substances against a gradient. Cellular systems that move materials against a gradient are referred to as pumps.

3.5 Active Transport, Endocytosis, and Exocytosis Active transport: requires energy input from a cell and enables a cell to move a substance against its concentration gradient. It drives molecules across a membrane from lower to higher concentration. Passive transport requires no energy from the cell. Active transport is powered by chemical energy (ATP). Active transport occurs through transport protein pumps. Cells use active transport to maintain homeostasis.

3.5 Active Transport, Endocytosis, and Exocytosis A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. Cells use energy to transport material in vesicles. Endocytosis is the process of taking in liquids or larger molecules into a cell by engulfing in a vesicle; requires energy Phagocytosis is a type of endocytosis.

3.5 Active Transport, Endocytosis, and Exocytosis A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. Cells use energy to transport material in vesicles. Exocytosis is the process of expelling material from the cell by fusion of a vesicle with the membrane

“Cell Transport”

8._____________ is the molecule that powers active transport. Glucose is mentioned as a molecule that needs a transport protein to get across the cell membrane into the cell. This is an example of facilitated diffusion, which is a type of 9.__________(active/passive) transport. The video talks about plants cells needing carbohydrates to build their cell walls. They need to use 10._____________(endocytosis/exocytosis) to get that large carbohydrate molecules across the cell membrane and into the cell.