Final answer:
Transport proteins, carrier proteins, glucose transporters, and aquaporins are molecules that assist in the transport of materials into the cell, mostly through facilitated diffusion which does not require energy.
Step-by-step explanation:
Molecules that Assist Transport of Materials into the Cell
Various molecules assist in the transport of materials into the cell. Some of these include:
- Transport proteins: Integral membrane proteins that create passageways for materials to flow through.
- Carrier proteins: They specifically interact with the molecule to be transported, which allows hormones, neurotransmitters, and other substances to pass.
- Glucose transporters: A type of carrier protein specifically designed for the transport of glucose through facilitated transport.
- Aquaporins: Water channel proteins that allow water to move across the cell membrane.
These molecules operate predominantly through facilitated diffusion, a process that leverages the concentration gradient to transport substances without the expenditure of energy. Larger molecules and ions are typically repelled by the hydrophobic interior of the plasma membrane, and transport proteins assist by shielding these materials, thus allowing them to pass into the cell efficiently.