Enzymes Essay

5925 words - 24 pages

Enzymes Enzymes are catalysts. Most are proteins. (A few ribonucleoprotein
enzymes have been discovered and, for some of these, the catalytic
activity is in the RNA part rather than the protein part. Link to
discussion of these ribozymes.)

Enzymes bind temporarily to one or more of the reactants of the
reaction they catalyze. In doing so, they lower the amount of
activation energy needed and thus speed up the reaction.
Most of these interactions are weak and especially so if the atoms
involved are farther than about one angstrom from each other. So
successful binding of enzyme and substrate requires that the two
molecules be able to approach each other closely over a fairly broad
surface. Thus the analogy that a substrate molecule binds its enzyme
like a key in a lock.

This requirement for complementarity in the configuration of substrate
and enzyme explains the remarkable specificity of most enzymes.
Generally, a given enzyme is able to catalyze only a single chemical
reaction or, at most, a few reactions involving substrates sharing the
same general structure.

Competitive inhibition

[IMAGE]The necessity for a close, if brief, fit between enzyme and
substrate explains the phenomenon of competitive inhibition.

One of the enzymes needed for the release of energy within the cell is
succinic dehydrogenase.

Link to illustrated
discussion of the
citric acid cycle.

It catalyzes the oxidation (by the removal of two hydrogen atoms) of
succinic acid (a). If one adds malonic acid to cells, or to a test
tube mixture of succinic acid and the enzyme, the action of the enzyme
is strongly inhibited. This is because the structure of malonic acid
allows it to bind to the same site on the enzyme (b). But there is no
oxidation so no speedy release of products. The inhibition is called
competitive because if you increase the ratio of succinic to malonic
acid in the mixture, you will gradually restore the rate of catalysis.
At a 50:1 ratio, the two molecules compete on roughly equal terms for
the binding (=catalytic) site on the enzyme.

Factors Affecting Enzyme Action

[IMAGE]The activity of enzymes is strongly affected by changes in pH
and temperature. Each enzyme works best at a certain pH (left graph)
and temperature (right graph), its activity decreasing at values above
and below that point. This is not surprising considering the
importance of

* tertiary structure (i.e. shape) in enzyme function and

* noncovalent forces, e.g., ionic interactions and hydrogen bonds,
in determining that shape.


* the protease pepsin works best as a pH of 1-2 (found in the

Find Another Essay On Enzymes

Enzymes Essay

1194 words - 5 pages , 28, 50, and 65. Then these enzymes where cooled down to room temperature before the procedure above was repeated again.pH experiment- First 5 petri dishes of different levels of pH were poured into them, the levels of pH included; a pH of 3, 5, 7, 10, and 12. Then 10 ml. of the enzyme mix was poured into each dish. This giving the different levels of pH for the enzymes. From there, the disks were soaked in the mix and the experiment carried on

Enzymes Essay

1005 words - 4 pages Enzymes Enzymes are complex proteins that carry out essentially every chemical reaction in the human body. Enzymes function as biological catalyst, regulating the rate at which chemical reactions proceed without themselves being altered in the process. In this particular experiment we recognized benzoquinone and examined two numbers of factors to determine their effects

Enzymes in Industry

2395 words - 10 pages Enzymes in Industry Enzymes are described as chemical a catalyst that is they speed up the rate of reaction. Enzymes have enormous potential in the commercial world. They are cheap to use in industry and they do not need high temperatures to work. They work at neutral PH and normal atmospheric pressure. This reduces the costs of fuel in industry and are energy saving. Also, enzymes can be reused. This means that

Application of Enzymes

1405 words - 6 pages some special helper known as 'enzyme.'Enzymes are proteins that catalyze or accelerate chemical reactions. Enzymes are biochemical catalysts. Almost all processes in the cell need enzymes in order to occur at significant rates.Enzymes have variety of application. Trevan (1987) has grouped the applications into four broad categories:Therapeutic usesAnalytical usesManipulative uses, andIndustrial usesTherapeutic uses:Enzymes are used for this

Introduction to Enzymes

551 words - 2 pages Leonardo MitchellBiologyEnzymesEnzymes are proteins made up of amino acids, which act as biological catalysts. This means they speed up chemical reactions that take place in all cells. They are the ones which determine whether a substance is broken down or built up. In reactions that include enzymes, the molecules, which react, are called substrates, which have a complementary relation with the active site, and the produced molecules are called

Lab: Enzymes – Protein Catalysts

922 words - 4 pages Lab: Enzymes – Protein Catalysts Abstract: Enzymes are catalysts therefore we can state that they work to start a reaction or speed it up. The chemical transformed due to the enzyme (catalase) is known as the substrate. In this lab the chemical used was hydrogen peroxide because it can be broken down by catalase. The substrate in this lab would be hydrogen peroxide and the enzymes used will be catalase which is found in both potatoes and

Enzymes in Wine Making

651 words - 3 pages Enzymes are biological catalysts which speeds up chemical reactions without being used up. There are three main factors which affect enzyme activity, and determines if their rate of reaction which are; sufficient energy (temperature), the pH, and the concentration. When there is a reaction, there must be energy around, the higher the energy, the faster the reaction because the particles will move faster therefore the chance of the particles to

Investigation of Enzymes

1279 words - 5 pages Investigation of Enzymes The majority of the reactions that occur in living organisms are enzyme-controlled. Without them, the rate of the reactions would be so slow as to cause serious, if not fatal, damage. Without enzymes toxins would soon build up and the supply of respiratory substrate would decrease. Enzymes are proteins and thus have a specific shape. They are therefore specific in the reactions that they

Enzymes - Lactose-Free milk

6513 words - 26 pages PlanAim: The purpose of this experiment is to investigate what size of bead would produce a higher concentration of glucose, after the milk has been poured into the column containing the immobilised lactase enzymes. The experiment would also be done using two different types of milk (Semi-skimmed and Whole milk) in order to see the difference in the amount of lactose present in each.HypothesisThe smaller the size of the beads in the column, the

Enzymes (An Experiment)

1152 words - 5 pages Problem The phenomenon that we were looking at was how enzymes in potatoes react with substrate. The enzyme will react with the substrate and use the substrate up but the enzyme will regenerate until the substrate is used up. The reaction for this can be written as: E+S ES E+P Where E is the enzyme, S is the substrate, ES is a stage called enzyme-substrate, and P is the product. This reaction in the body is continuous and always equal

Enzymes Enhances the Digestive System

622 words - 3 pages chemical changes of the gastrointestinal system and it’s enzymes. Enzymes are also known as proteins, and they are responsible for bringing about the responses in the body. Enzymes enhance the speed of the responses in the body without being devoured by the body’s responses. Proteins or enzymes of the gastrointestinal system bring about the change of carbohydrates into two different categories of sugars known as monosaccharides and disaccharides

Similar Essays

Enzymes Essay

1472 words - 6 pages Enzymes Enzymes are biological catalysts. A catalyst is defined as a substance that increases the rate of a chemical reaction without itself undergoing any permanentchange. Enzymes do precisely this in living things. Without them, the rate of the reactions would be so slow as to cause serious, if not fatal, damage. Enzymes have two main functions: To act as highly specific catalysts, and also to provide a way of

Enzymes Essay 1235 Words

1235 words - 5 pages Enzymes'Enzymes are biological catalysts. A catalyst is defined as a substance that increases the rate of a chemical reaction without itself undergoing any permanentchange. Enzymes do precisely this in living things. Without them, the rate of the reactions would be so slow as to cause serious, if not fatal, damage. Enzymes have two main functions: To act as highly specific catalysts, and also to provide a way of controlling reactions, the amount

Enzymes Essay 1597 Words

1597 words - 6 pages Enzymes Enzymes are biological catalysts that carry out thousands of chemical reactions that occur in living cells. They are a class of proteins that have a unique three dimensional structure that allows it to bind with a specific substrate to facilitate a reaction. Many biological reactions will not occur spontaneously in the cell; there is simply not enough energy for the reaction to take place. Enzymes make

Enzymes Essay 1407 Words

1407 words - 6 pages Enzymes are presented in many different shapes and sizes because form fits function. Enzymes play an active role in everyday life, in every living organism. What all enzymes have in common is that they are proteins meant to speed up chemical reactions because without them reactions would occur at an extremely slow rate. This would be a conflict for every living thing which is why enzymes are so important. Enzymes are defined as “a protein