Lactase (a protein)
From Proteopedia
(New page: ==Structure== Lactase is a macromolecule assembled from amino acid building blocks. The amino acids are linked through condensation reactions, forming a linear chain (the primary structur...) |
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| + | Lactase is an enzyme, i.e. a protein that catalyzes a chemical reaction. The function of lactase is to hydrolyze lactose, a disaccharide found in cow milk and milk products. Individuals who lack lactase have trouble digesting milk unless they take a medication like Lactaid, which contains lactase from yeasts or bacteria to supplement the lack of endogenous enzyme. | ||
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==Structure== | ==Structure== | ||
| - | Lactase is a macromolecule assembled from amino acid building blocks. The amino acids are linked through condensation reactions, forming a linear chain (the primary structure) also called a polypeptide. In order to be functional, the polypeptide has the fold into a specific shape by forming secondary and tertiary structure. Secondary structure refers to the pattern of hydrogen bonds formed by the main chain of the amino acid residues (the atoms NH-CH-CO common to all 21 amino acids). Tertiary structure refers to the interactions between the side chains of different secondary structure elements. Lactase, like many proteins, also shows | + | Lactase is a macromolecule assembled from amino acid building blocks. The amino acids are linked through condensation reactions, forming a linear chain (the primary structure) also called a polypeptide. In order to be functional, the polypeptide has the fold into a specific shape by forming secondary and tertiary structure. Secondary structure refers to the pattern of hydrogen bonds formed by the main chain of the amino acid residues (the atoms NH-CH-CO common to all 21 amino acids). Tertiary structure refers to the interactions between the side chains of different secondary structure elements. Lactase, like many proteins, also shows quaternary structure. This means that it consists of multiple polypeptides (or subunits) assembled together to form the functional protein. |
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| + | ==Function== | ||
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| + | Like all enzymes, lactase first binds to its substrate lactose. While bound to the enzyme, lactose reacts with water, causing its hydrolysis into the carbohydrate building blocks galactose and glucose. The building blocks then leave the enzyme, which is ready for another lactose molecule to bind. In this way, a single enzyme can support millions of consecutive reactions. | ||
Revision as of 17:21, 23 August 2024
Lactase is an enzyme, i.e. a protein that catalyzes a chemical reaction. The function of lactase is to hydrolyze lactose, a disaccharide found in cow milk and milk products. Individuals who lack lactase have trouble digesting milk unless they take a medication like Lactaid, which contains lactase from yeasts or bacteria to supplement the lack of endogenous enzyme.
Structure
Lactase is a macromolecule assembled from amino acid building blocks. The amino acids are linked through condensation reactions, forming a linear chain (the primary structure) also called a polypeptide. In order to be functional, the polypeptide has the fold into a specific shape by forming secondary and tertiary structure. Secondary structure refers to the pattern of hydrogen bonds formed by the main chain of the amino acid residues (the atoms NH-CH-CO common to all 21 amino acids). Tertiary structure refers to the interactions between the side chains of different secondary structure elements. Lactase, like many proteins, also shows quaternary structure. This means that it consists of multiple polypeptides (or subunits) assembled together to form the functional protein.
Function
Like all enzymes, lactase first binds to its substrate lactose. While bound to the enzyme, lactose reacts with water, causing its hydrolysis into the carbohydrate building blocks galactose and glucose. The building blocks then leave the enzyme, which is ready for another lactose molecule to bind. In this way, a single enzyme can support millions of consecutive reactions.
