Cell transport interactive

  • Due No Due Date
  • Points 1

Before beginning read this:

Vocab to know:

  1. Impenetrable - Difficult to pass through or understand.
  2. Facilitated - Made easier or helped in some way.
  3. Electrical charge - A property of particles like ions when they carry a positive or negative electric charge.
  4. Exocytosis - The process of releasing substances from a cell by fusing a vesicle with the cell membrane.
  5. Phagocytosis - A process where a cell engulfs and "eats" solid particles or other cells.

  6. Organelles - These are specialized structures within a cell that have specific functions, like the nucleus or mitochondria.

  7. Cytoplasm - The gel-like substance inside a cell, where many cellular processes occur.

  8. Ion channels - These are proteins in the cell membrane that allow ions to pass through.

  9. Lipid bilayer - A double layer of lipids (fats) that makes up the cell membrane.

  10. Active transport - The movement of molecules or ions across the cell membrane with the use of energy.

 

The cell membrane is super important for a cell's survival. It's like a protective barrier that separates the inside of the cell from the outside world. It keeps the important stuff like the cytoplasm and tiny organs (we call them organelles) safe inside, and it keeps out harmful things and tiny particles. But it's not a solid wall. In fact, if it were, the cell would run out of nutrients and oxygen and wouldn't be able to get more, and it would die.

The cell membrane is also known as the plasma membrane. Think of it more like a bag made of tightly woven fabric than a solid wall. Some things, like gases such as oxygen and carbon dioxide, and small molecules, can easily pass through the membrane. Water and other tiny molecules can move in and out of the cell pretty easily too. But there are also special openings, like gates, that allow other substances to go in and out. These gates are called ion channels, GluT transporters, and protein pumps.

These gates are kind of like the drawstring opening of a bag. They help the cell take in or release bigger molecules, like glucose, and ions (those are atoms with an electrical charge) that can't pass through the main part of the membrane. Depending on the kind of stuff and the environment around the cell, the cell might have to actively push the molecules or ions through these gates, which we call active transport. Sometimes it uses proteins to help the molecules move, which is called facilitated transport. And sometimes, it just lets larger molecules and ions move in and out through open channels.

For really big molecules and particles to get across the cell membrane, the cell has to change the structure of its membrane temporarily. Enzymes, which are large proteins made by cells in the digestive system, are way too big to fit through the protein pumps and ion channels of the cells that make them. So, these cells wrap these enzymes in pouches, called vacuoles, which are made of the same stuff as the cell membrane. When the vacuole touches the cell membrane, they split open where they touch and release the enzymes. This whole process is called exocytosis.

Endocytosis is a bit like the opposite of exocytosis. Cells "swallow" large molecules and stuff by wrapping their cell membrane around them to make vacuoles. Once the object is all wrapped up, the vacuole is pinched off and released into the inside of the cell. There's a special type of endocytosis called phagocytosis, which allows certain cells, like white blood cells, to eat other cells. The process of phagocytosis is pretty much the same as endocytosis, but it's used for ingesting larger objects that are sometimes bigger than the cell itself.

 

GO HERE for the interactive Links to an external site.

 

In the text box, answer these questions:

  1. What is the role of the cell membrane, and why is it crucial for a cell's survival?
  2. How does the cell membrane function, and what is its similarity to a bag made of tightly woven fabric?
  3. Explain the different ways substances can move through the cell membrane. Give examples for each.
  4. What are exocytosis and endocytosis, and how do they help in transporting substances across the cell membrane?
  5. Can you describe the process of phagocytosis and identify the types of cells that use this mechanism for consuming other cells or particles?

  6. Is energy required for substances to pass into or out of the cell?

  7.  

    Which of the methods of transport into or out of the cell require energy? Which do not?

 

SUBMIT ANSWERS HERE.

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