What are isoenzymes?

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Hi everyone. Our next question says which statement or statements is or are correct regarding isoenzymes. So we we read through each of these statements, evaluating them. One by one statement, one says isoenzymes are different forms of the same enzyme that catalyze the same chemical reaction but differ in their molecular structure. So this is pretty easy to remember given that prefix iso I can think of isomers and yes, this is the definition of an isoenzyme. They have different forms usually in the form of different amino acid structures or excuse me, I should say different amino acid sequences that catalyze the same reaction but differ in their molecular structure. So they have these slight differences in the structure due to different amino acid sequences um but still manage to catalyze the same reaction. So statement one is a correct statement. Lets look at number two isoenzymes are always identical in structure and function. Well, they may be identical in function. They catalyze the same reaction but they are not identical in structure because again, they can have a different amino acid sequence. So statement two is incorrect, we'll cross that out. Step three says isoenzymes can vary in their kinetic properties such as affinity for substrates and maximum reaction rates. And this is correct if we think about the fact they have different amino acid sequences. Well, the amino acid sequences will affect the shape of the molecule because there are groups being different, they could have slightly different shapes, which means makes them perhaps have different affinities for different substrates, catalyze reaction at different rates. So have different maximum reaction rates. So statement three is indeed correct. And then finally, choice four isoenzymes may be tissue specific, allowing for specialized regulation and adaptation to the needs of different tissues. Well, this is also correct if you think about why we'd want these ISOS them, why they would stay around. It would be that perhaps that variation gives an advantage. So maybe in different tissues, having slightly different characteristics in structure and function helps adapt that enzyme to the needs. There are different metabolic requirements, different, you know, environment there, the specialized function of those tissues. So our statements that are correct here regarding I enzymes are statement 13 and four. See you in the next video.

What are isoenzymes?

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Key Concepts

Isoenzymes

Enzyme Structure

Metabolic Regulation