Question

some proteins carry across the membrane while others
a is a protein that
the molecule that a receptor binds to is called a
when a receptor and a ligand bind, they
two major types of receptors are :

1. are within a cell.

chemicals that bind to the receptors are and
into the cell to do a specific function.

1. attach to chemicals or molecules that

cannot cross the cell membrane and carry into the cell for a
particular function.
cell wall
the cell wall:

• is found in plants, algae, fungi and prokaryotes.

Explanation:

Some proteins are transporters that carry substances across the membrane, while others are enzymes that catalyze reactions. A receptor is a protein that binds to specific molecules. The molecule bound by a receptor is a ligand. When they bind, they trigger a response. Intracellular receptors are within the cell and bind to substances that can cross the membrane. Cell - surface receptors attach to substances that cannot cross the membrane and carry signals into the cell. The cell wall provides structural support and protection in plants, algae, fungi and prokaryotes.

Answer:

Some proteins carry substances across the membrane while others act as enzymes.
A receptor is a protein that binds to specific molecules.
The molecule that a receptor binds to is called a ligand.
When a receptor and a ligand bind, they trigger a response.
Two major types of receptors are:

1. Intracellular receptors are within a cell. Chemicals that bind to the receptors are able to cross the membrane and carry out a specific function.
2. Cell - surface receptors attach to chemicals or molecules that cannot cross the cell membrane and carry signals into the cell for a particular function.

The cell wall:

• is found in plants, algae, fungi and prokaryotes.
• provides structural support.
• offers protection.