Enzymes are proteins that accelerate, or catalyze, chemical reactions. In these reactions, the molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules: the products. Almost all processes in the cell need enzymes in order to occur at significant rates. Consequently, since enzymes are extremely selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell.
The activities of enzymes are determined by their three-dimensional structure.
Most enzymes are much larger than the substrates they act on, and only a very small portion of the enzyme (around 3-4 amino acids) is directly involved in catalysis. The region that contains these catalytic residues and binds the substrate and then carries out the reaction is known as the active site. Some enzymes also contain sites that bind cofactors, which are needed for catalysis. Some enzymes also have binding sites for small molecules, which are often direct or indirect products or substrates of the reaction catalyzed. This binding can serve to increase or decrease the enzyme's activity, providing a means for feedback regulation.
Like all proteins, enzymes are made as long, linear chains of amino acids that fold to produce a three-dimensional product. Each unique amino acid sequence produces a unique structure, which has unique properties. Individual protein chains may sometimes group together to form a protein complex. Most enzymes can be denatured-that is, unfolded and inactivated-by heating, which destroys the three-dimensional structure of the protein. Depending on the enzyme, denaturation may be reversible or irreversible.
Some enzymes do not need any additional components to show full activity. However, others require non-protein molecules to be bound for activity. Cofactors can be either inorganic (e.g., metal ions and iron-sulfur clusters) or organic compounds, (e.g., flavin and heme). Organic cofactors are usually called prosthetic groups. Tightly-bound cofactors are distinguished from coenzymes, such as NADH, since cofactors are regenerated as part of the catalytic mechanism and are not released from the active site during the reaction.
An example of an enzyme that contains a cofactor is carbonic anhydrase, and is shown in the diagram above with four zinc cofactors bound in its active sites. These tightly-bound molecules are usually found in the active site and are involved in catalysis. For example, flavin and heme cofactors are often involved in redox reactions.
Enzymes that require a cofactor but do not have one bound are called apoenzymes. An apoenzyme together with its cofactor(s) is called a holoenzyme (i.e., the active form). Most cofactors are not covalently attached to an enzyme, but are very tightly bound. However, organic prosthetic groups can be covalently bound (e.g., thiamine pyrophosphate in the enzyme pyruvate dehydrogenase).
Coenzymes are small molecules that transport chemical groups from one enzyme to another. Some of these chemicals such as riboflavin, thiamine and folic acid are vitamins, this is when these compounds cannot be made in the body and must be acquired from the diet. The chemical groups carried include the hydride ion (H+ + 2e-) carried by NAD or NADP+, the acetyl group carried by coenzyme A, formyl, methenyl or methyl groups carried by folic acid and the methyl group carried by S-adenosylmethionine.
for more:
http://en.wikipedia.org/wiki/Enzyme
As enzymes are made up of proteins, and a previous question here:
What_chemical_elements_are_protein_made_of
lists the chemical composition of protein, I would say
1.) sulfur
2.) carbon
3.) hydrogen
4.) oxygen
5.) nitrogen
Enzymes are any of various proteins and capable of producing certain chemical changes in organic substances by catalytic action.
Enzymes are nothing but proteins with bio-catalytic action. They are made up of amino acids.
Enzymes are proteins.
Amino Acids
goni gona
NO. The enzyme acts on the substrate. The substrate is the chemical/compound being altered by the action of the enzyme. They are NOT the same.
An enzyme is a protein that speeds up the rate of chemical reactions.
In a chemical reaction, reactants bind to the enzyme at the active site. The active site is determined randomly each time a bond occurs.
It denotes an enzyme
an enzyme
The enzyme is a biochemical catalyst.
All enzyme's are catalysts for certain chemical reactions. Each enzyme will only work with a certain substrate one analogy being that the enzyme is a key and the substrate is a keyhole, and each enzyme has a unique enzyme.
an enzyme is protien that catalyzes chemical reactions for organisms
enzyme sped up the chemical reaction
its called an enzyme
The shape allows the enzyme to carry out specific chemical reactions.
This chemical is an enzyme inhibitor.
to speed up a chemical reaction
Enzyme or catalyst
Enzyme is specific
Enzyme.
NO. The enzyme acts on the substrate. The substrate is the chemical/compound being altered by the action of the enzyme. They are NOT the same.