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What is an enzyme and how are enzymes important in living organisms?

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akatude | Student, Undergraduate | Valedictorian

Posted June 21, 2012 at 1:51 AM via web

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What is an enzyme and how are enzymes important in living organisms?

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trophyhunter1 | College Teacher | (Level 3) Senior Educator

Posted June 21, 2012 at 6:18 PM (Answer #1)

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Enzymes are organic catalysts which aid in facilitating chemical reactions in the body. Enzymes are needed for metabolic pathways in the body, respiration, digestion and other important life processes. When enzymes function properly, homeostasis is maintained. However, if an enzyme is lacking or has an incorrect shape due to a genetic mutation, this can lead to disease within an organism. An example of this is the disease phenylketonuria or PKU. It is an autosomal recessive disorder which involves a gene mutation in the gene for the enzyme phenylalanine hydroxylase(PAH). This enzyme is part of a metabolic pathway in which the amino acid phenylalanine is converted to tyrosine. In the person with PKU disease, they have an enzyme that is defective and the activity is reduced. Therefore, phenylalanine accumulates and is converted to phenylpyruvate, which is found in the urine. It also builds up in the brain, leading to mental retardation and brain damage. By restricting the person's intake of protein, which contains phenylalanine, the person can have a normal life span and mental development. This is but one example of the many enzymes which have very necessary and specific functions in the body.

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chaobas | College Teacher | Valedictorian

Posted June 21, 2012 at 2:44 AM (Answer #2)

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Enzymes are the proteins that enhance the rate of a reaction. They are similar to catalyst.

 

Now these enzymne are an imporatnt part of metabolism. All most all biological reaction need an enzyme. They have multiple function. They can breakdown a macro-molecule to simple compound 

eg: Carbohydrates ------(amylase)----> Glucose

glucose, which is a simplke compound is broken down from carbohydrates with the help of amylase enzyme. It is the part of digestion.

And also enzyme helps in synthesizing of biger molecule like proteins from amino acids.

amino acid -----(dehydogenase)----> proteins

here protiens are the polymer of amino acid, these amino acid under go dehydrolysis,that is by loosing a water molecule, with the help of dehydrolyase and form the polymer.

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nirmita | Student, Grade 10 | Honors

Posted June 21, 2012 at 8:36 AM (Answer #3)

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Enzymes are basically proteins which enhance the rate of breakdown of food in our body and the are even required by other organism for various functioning related to their body.

These enzymes are bio-catlyst which enhance the rate of reaction.

An excellent example of use of enzymes is seen in the glow-worms which glow because of different enzymal reaction which are going on in these tiny insects and because that they can fly easily at night.

Plants require enzymes for photosynthesis, respiration, etc. and we require it for digestion, respiration, assimilation, etc.

Intance of one enzyme used during digestion of protein,

Protein---(renine)--->curd

Milk Protein Caesin changes to curd after renine's action on. Hence it can be said that thses enzymes help us in better absorption by converting complex food into simpler molecules.

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sanjeetmanna | College Teacher | (Level 3) Assistant Educator

Posted June 23, 2012 at 5:42 PM (Answer #4)

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Enzymes play the main role of catalysis. they are activators.

Inhibitor stopes the reaction where as activator activtes the reaction and make the reaction to move forward by increaseing the rate of the rection that is decreasing the activation energy.

Enzymes are mainly proteins, it is said that all enzymes are proteins but all proteins are not enzymes. Enzymes are also called as biocatalyst.

They are globular in shape

They are very specific to there substrated (Lock and key mechanism theory)

Enzyme activity is affected by substrate concentration, temperature, PH and inhibitors.

They have active site where the substrate bindes.

They need cofactores to perform complete function.

There are various classes of Enzymes they are 

Oxidoreductase

Transferases

Hydrolases

Lyases

Isomerases

Ligases. ets.,

Examples of Exzymes...

Amylase

maltase

sucrase

pepsin

catalase...

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