Cellular Transport for Middle School Science

Cellular transport is how things get in and out of a cell. The two main types of cellular transport are active transport and passive transport. Unlike passive transport, active transport takes energy. The cell uses ATP for energy, including the energy needed for active transport.

The flashcards you see below are free at Teachers Pay Teachers. You can also read more about cellular transport below.

Cellular Transport

Cellular Transport

Cells are like tiny bustling cities, constantly taking in nutrients and oxygen, removing waste products, and communicating with their surroundings. To do this, they need to transport substances across their cell membranes. This process is called cellular transport. Just like a city needs roads, trains, and trucks to move goods and people, cells have specialized mechanisms to move molecules and other substances in and out of the cell. This transport is crucial for maintaining homeostasis, the stable internal environment that cells need to survive and function.

Types of Cellular Transport

There are two main types of cellular transport: passive and active transport.

• Passive Transport

  Passive transport doesn't require the cell to use energy. It's like a ball rolling downhill—it moves naturally from an area of high concentration to low concentration. There are a few types of passive transport:

  
  

  • Diffusion: The movement of small molecules, like oxygen or carbon dioxide, across the cell membrane from an area of high concentration to low concentration.

    
    

  • Osmosis: The movement of water across a semi-permeable membrane from an area of high water concentration to low water concentration.

    
    

  • Facilitated Diffusion: Larger molecules, like glucose, can't easily pass through the cell membrane. They need help from special protein channels that act like doorways.

    
    

• Active Transport

  Active transport requires the cell to use energy, like a pump pushing water uphill. It's necessary to move substances against their concentration gradient (from low to high concentration). There are a few ways cells do this:

  
  

  • Protein Pumps: Special proteins embedded in the cell membrane act as pumps, using energy to move molecules like sodium and potassium ions across the membrane.

    
    

  • Endocytosis and Exocytosis: These processes involve the cell membrane engulfing or expelling large particles or droplets of fluid.

Why is Cellular Transport Important?

Cellular transport is essential for maintaining homeostasis, the stable internal environment that cells need to survive and function. It allows cells to:

• obtain nutrients and oxygen

• remove waste products

• regulate water and ion balance

• communicate with other cells

• without cellular transport, our cells would be unable to perform their vital functions, and our bodies would not be able to survive

The Biosphere

Middle School Science