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The calculation fraction of enzyme bound to substrate is used when determining the Michaelisâ??Menten equation. It is widely used in the enzyme kinetics.
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How do you determine Vmax in enzyme kinetics?
Vmax is the maxim initial velocity (Vo) that an enzyme can achieve. Initial velocity is defined as the catalytic rate when substrate concentration is high, enough to saturate the enzyme, and the product concentration is low enough to neglect the rate of the reverse reaction. Therefore, the Vmax is the maximum catalytic rate that can be achieved by a particular enzyme. Km is determined as the substrate concentration at which 1/2 Vmax is achieved. This kinetic parameter therefore importantly defines the affinity of the substrate for the enzyme. These two parameters for a specific enzyme defines: Vmax - the rate at which a substrate will be converted to product once bound to the enzyme. Km - how effectively the enzyme would bind he substrate, hence affinity.
Example of membrane bound enzymes?
Membrane bound enzymes are enzymes in a membrane that are responsible for the maintenance of cellular functions such as ion transport, secretion and uptake of a variety of substances, as well as cell to cell interactions. A membrane-bound organelle is an organelle surrounded by a plasma membrane.
Why co factor more stable than enzyme?
A cofactor is a non-protein chemical compound that is bound to a protein. The protein they are bound to are often enzymes. Cofactors are considered "helper molecules" that assist in biochemical transformations. An enzyme are large biochemical molecules that is responsible for many chemical interconversions that sustain life. A cofactor is more stable because it tightly binds to the enzymes to make them stronger.
Difference between activator and prosthetic groups?
Prosthetic groups can be as simple as a single metal ion bound into the enzyme's structure, or may be a more complicated organic molecule (which might also contain a metal ion). it is permanently bonded to enzyme. Activator is only metal ion that is detachable. source:chemguide.co.uk Stuffidious.com
What chemical is a enzyme?
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
Synthesis of an inducible enzyme requires?
Substrate bound to a repressor Chris G.
When the substrates are bound to the enzyme it is called the?
An active site. Sometimes the active site can be disabled from inhibitors.
What is an activation site?
An active or activation site is a small opening in an enzyme where substrate molecules are bound, and go through a chemical reaction. This reaction is caused by the collision a substrate that slots into the active site of the enzyme.
This is a modification of the lock and key model that suggests the active site of an enzyme is continually reshaped by interactions with the substrate until the substrate is completely bound and the c?
induced fit
What is the simple definition of saturation kinetics in biochemistry?
Saturation Kinetics- an enzyme reaction in which there is enough enzymes to constantly have a substrate bound them and therefore the reaction is occurring at Vmax. This velocity is only limited by the concentration of substrates, not the enzyme.
Compare enzyme activity with a lock and key?
Lock and key is an analogy of enzyme catalysis in a cellular reaction. The lock and key are compared directly to the substrate and enzyme, because of the high specificity of their physical shape. Enzymes participate in the reaction they catalyze. The reactant molecule (substrate) binds to the enzyme molecule at a particular location called the active site. (this is compared to the lock with keyhole) The highly specific nature of an enzyme is due to very precisely defined arrangement of atoms in the active site(again, this is the lock in the analogy). The substrate molecule must have a matching shape (here is the key) that will fit into the active site. The bond breaking and bond forming processes that transform the substrate into products occur while the substrate is bound to the active site of enzyme. In other words its something like a jigsaw puzzle where the substrate fits into the enzyme. The reaction occurs and the substrate then leaves the enzyme as products. ( Not my work. Found it on Yahoo Answers.....Do not give me credit...Thought I should do this to help people out =] ) Edited answer for readability and clarity - thanks!
How do you determine Vmax in enzyme kinetics?
Vmax is the maxim initial velocity (Vo) that an enzyme can achieve. Initial velocity is defined as the catalytic rate when substrate concentration is high, enough to saturate the enzyme, and the product concentration is low enough to neglect the rate of the reverse reaction. Therefore, the Vmax is the maximum catalytic rate that can be achieved by a particular enzyme. Km is determined as the substrate concentration at which 1/2 Vmax is achieved. This kinetic parameter therefore importantly defines the affinity of the substrate for the enzyme. These two parameters for a specific enzyme defines: Vmax - the rate at which a substrate will be converted to product once bound to the enzyme. Km - how effectively the enzyme would bind he substrate, hence affinity.
What blocks enzyme activity by binding to the active site of an enzyme?
Competitive inhibitors reduce enzyme activity by binding (in competition with the enzyme's substrate) to the active site. These inhibitors may be reversible or irreversible. With reversible inhibitors, which may release the enzyme, concentrations much higher than the concentration of the substrate would be required to completely block enzyme activity, and even then one or two reactions may take place over long periods of time. With irreversible inhibitors, which permanently attach to the enzyme, enzyme activity could be completely blocked when the amount of inhibitor matches the amount of enzyme. Competitive inhibition reduces the enzymes ability to bind substrate (so it lowers the KM) but does not alter the maximum rate (very high substrate concentrations would out compete for enzyme binding).Other types of inhibitors work in other ways. Non-competitive inhibitors bind to the enzyme on a site other than the active site. These too may be reversible or irreversible. Binding does not compete with substrate, so concentrations to completely block enzyme activity do not have to be as high as reversible competitive inhibitors. Non-competitive inhibition reduces the apparent maximum rate for the enzyme.Uncompetitive inhibitors bind only when the substrate is also bound to the enzyme (they bind to the enzyme-substrate complex). Both the maximum rate and substrate binding affinities appear lower.
What is the definition of binding?
Law. To place under legal obligation by contract or oath. Chemistry. To combine with, form a chemical bond with, or be taken up by, as an enzyme with its substrate. To compel, obligate, or unite: bound by a deep sense of duty; bound by a common interest in sports.
When an enzyme catalyze a reaction?
Enzyme will catalyse when the substrate come close enough to interact with enzyme's active site (proximity and orientation). The rate of enzymatic reactions is influenced by the condition such as temperature or pH that favors the chemical environment, and when a co-factor is already bound (not for all enzymes).
draw lb plot of mixed inhibition with increased concentration of inhibitor?
In a mixed inhibition scenario, as the concentration of the inhibitor increases, the Lineweaver-Burk (LB) plot takes on a distinctive pattern. Unlike uncompetitive or competitive inhibition, mixed inhibition involves the inhibitor binding to both the enzyme-substrate complex and the free enzyme, affecting the reaction kinetics. As the inhibitor concentration rises, the LB plot displays converging lines, indicating that the apparent affinity of the enzyme for the substrate diminishes. This convergence suggests that the inhibitor alters both the enzyme's active form and its substrate-bound configuration. The LB plot, in this context, serves as a visual representation of how the inhibitor impacts the enzyme's catalytic activity, offering insights into the complex interplay between substrates, enzymes, and inhibitors at varying concentrations.
What is a co substrate?
A co-substrate is a co-factor that transforms an apoenzyme into a holoenzyme. However, it is not tightly bound to the protein and freely binds and releases (but is not chemically altered). This is different from a tightly bound cofactor such as heme in hemeglobin, these are termed prosthetic groups.
