Q:

How are glucose molecules moved into a cell?

A:

Quick Answer

Glucose molecules are transported across cell membranes by facilitated diffusion or active transport. Most of the time, the former process takes place, as it requires no energy from the cell. Active transport indirectly requires energy from the hydrolysis of ATP.

  Know More

Full Answer

When glucose molecules move into the cell by facilitated diffusion, the concentration gradient plays an essential part. Glucose only enters the cell by diffusion if its intracellular concentration is lower than the extracellular one. To move across the cell membrane without requiring any energy, glucose needs a protein that acts like a carrier. Because there is a limited number of transporting proteins, this process reaches a maximum rate of transport that cannot be improved, even if the concentrations on either side of the membrane continue to present a significant difference.

Glucose enters the cell against the concentration gradient, by active transport. In fact, glucose takes part in a process of cotransport, along with an ion such as Na+. When the sodium ion binds to the receptor, the binding of glucose is also stimulated, despite its concentration gradient. The receptor closes on the exterior side and opens on the inside of the cell, releasing the sodium ion along with the glucose molecule. The passive and active glucose transport systems work independently, and drugs that inhibit one of the processes do not influence the other.

Learn more about Human Anatomy

Related Questions

  • Q:

    What causes glucose in urine?

    A:

    According to WebMD, high blood sugar levels cause excess glucose in the urine. High blood sugar levels are common in people with uncontrolled diabetes. When an individual's blood sugar level is high, it can spill into the urine. Glucose in the urine can also occur if the kidneys are suffering from damage or disease.

    Full Answer >
    Filed Under:
  • Q:

    What is a major type of lipid found in cell membranes?

    A:

    A major type of lipid found in cell membranes is the phospholipid. The phospholipid is made up of a polar head and two non-polar tails.

    Full Answer >
    Filed Under:
  • Q:

    What is a human cell?

    A:

    A human cell is a tiny container of chemicals, making it the basic building block of all human life. There are trillions of cells in a human being, and they determine the structure and function of each person.

    Full Answer >
    Filed Under:
  • Q:

    What is sickle cell trait?

    A:

    Sickle cell trait is the expression of the sickle cell gene that is passed on from one parent, according to WebMD. Individuals possessing the trait are carriers of sickle cell-related diseases, such as sickle cell anemia.

    Full Answer >
    Filed Under:

Explore