Aprotein that acts as a hormone is 1. collagen 2.methionine 3. pepsin 4. insulin

The correct answer is 4. insulin

Explanation:

Proteins are made up of amino acids which are joined together by peptide bond. Insulin is a peptide hormone which is made amino acids therefore it is also a protein. An insulin molecule is made up of 51 amino acid residues and 5808 Da is its molecular weight.

The insulin hormone is released by the beta cell of the pancreas. It is released when the level of glucose in the blood increased from the normal blood glucose level.  

It helps in conversion of glucose into glycogen and its storage in muscles and liver. So by doing this, it decrease the level of glucose in the blood. Therefore the right answer is 4.

cardiovascular system

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image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.