Question

Hemoglobin is a water-soluble, globular protein made of 2 alpha-hemoglobin and 2 beta-hemoglobin polypeptide chains. Hemoglobin is present in large amounts in the cytoplasm of red blood cells.Where in the cell are the alpha- and beta-hemoglobin proteins made?A. in the cytoplasm, by free cytoplasmic ribosomesB. by ribosomes docked to the rough ERC. by ribosomes docked to the nuclear envelopeD. by ribosomes docked to the plasma membraneE. by ribosomes in the mitochondria

Answer 1

The answer is A

Step-by-step explanation:

There are certain types of proteins that need to be sinthesized in the rough ERC in order to reach its final destination. These proteins are:

- Proteins that need to be exported from the cell.

- Proteins that need to be docked to either endomembranes or the plasma membrane.

- Hydrolytic lysosomal enzimes.

- Proteins that have a function in the lumen of certain organelles such as the endoplasmic reticulum, golgi or the nuclear envelope.

Hemoglobin doesn't fit in any of these cateogories, given that it is a cytoplasmic protein. Therefore, its synthesis begins and ends in the cytoplasm, where the protein performs its function.