Enzyme Lab Report

Enzyme is an essential concept in biology; they act as catalysts, speeding up chemical reactions by lowering the activation energy. According to the Lock & Key model, a specific substrate joins with a specific enzyme at the active site, to form the enzyme-substrate complex; this brings the reactants closer together to facilitate chemical reactions (Ophardt).

1. Both answers are correct. There are two different models for substrate binding: lock and key or induced fit. In the lock and key model, the active site of unbound enzymes fits perfectly with the complementary shape of its substrate. In the induced fit model, the enzyme changes shape to confirm to the substrate after binding.

An Enzyme is a protein that in essence speeds up biological reactions. So that would mean that a Catalase is an enzyme reaction that decomposes hydrogen peroxide to water and oxygen. It is primarily found in the liver and it is important in protecting the cell from damaging oxidative reactions.

Enzymes are proteins that act as a catalyst in bringing about specific biochemical reactions when met with particular substrates. Substrates will merge into a suitable area of the enzyme called an active site – this becomes the enzyme/substrate complex. Once the substrate is attached to the active site, the substrate will undergo a procedure where the substrate is modified and released as a product. There are different types of this that can occur, where either a chemical bond is broken in a substrate to produce two separate products; as in the ‘Induced-Fit’ model illustrated in figure 1.a. Chemical bonds can also be built between two substrates to produce a single product.

When the substrate enters the active site of an enzyme, the conditions of the active site are altered slightly in order to increase the reactivity and cause the creation of more

Once the enzyme-substrate complex has been established, the enzymes amino acid side chains convert the substrate to the product. The products are then released from the enzyme. The enzyme remains unchanged by the first reaction, thus is free to catalyze another reaction (Mitchell 2006).

During the enzyme-catalysed reaction, the substrate is changed and a product is formed. Because the enzyme remains unchanged it can continue to catalyse the same reaction multiple times. Each enzyme is specific to the reaction it catalyses. When enzymes are folded, they create an area known as the active site, the place that

BACKGROUND: Catalase (the enzyme) is found in yeast, it breaks down hydrogen peroxide (the substrate) into water and oxygen according to this equation. 2H2O2(aq) -------------------> 2H2O(l) + O2(g) + catalase(aq) One molecule of catalase can break 40 million molecules of hydrogen peroxide each second. Factors that affect the rate of reaction § Increasing the temperature increases the kinetic energy at which the enzyme and substrate collide.

The enzyme can change shape when bound by the substrate, which is triggered by the strong magnetic forces during binding. This change in shape aligns the two substrates in the positions in which they are connected by the hook-and-loop fastener (Figure 2). This simulation shows important features of the induced-fit model: sub- strate binding induces a change in the shape of the enzyme, which brings about the catalysis of the substrates into the product. This simulation helps tackle the misconceptions that the substrates bind with the enzyme in a lock-and-key manner and that it is the sub- strate, rather than the enzyme, that undergoes induced fit (College Board,

The substrate is the reactant substance, which enters the active site of an enzyme through induced fit by different chemical bonds such as hydrogen, or ionic bonding, where it will then be converted to a product. An enzyme-substrate complex is then formed and the rate of reaction rapidly progresses (Sandhyarani, 2011). Enzymes carry out reactions in optimal conditions, thus any changes in the environment affect the rate of which substrates and converted to products. Substrate and enzyme concentration, pH levels, and temperature are all environmental factors that may, increase the rate of reaction or if they are too extreme, denature the enzyme itself to prevent any further effectiveness (Karp, 2005).

Each enzyme is very specific and can only catalyze a certain reaction. The specific reaction catalyzed by an enzyme depends on the molecular structure and shape of a small area of the enzyme’s surface called the active site. The active site an attract and hold only its specific molecules. The target molecule that the enzyme attracts and acts upon is called the substrate. The substrate and the active site of the molecule must fit together very closely. Sometimes the enzyme changes its shape slightly to bring about the necessary fit.

In my experiment the substrate was the hydrogen peroxide, the enzyme that we used was hydrogen peroxide and the product that was formed was oxygen and water. This can be explained by an equation: Enzyme + Substrate ÞProduct In my experiment this is shown as: Catalase + H202 ÞH202 + 02 This

The purpose of this lab report is to investigate the effect of substrate concentration on enzyme activity as tested with the enzyme catalase and the substrate hydrogen peroxide at several concentrations to produce oxygen. It was assumed that an increase in hydrogen peroxide concentration would decrease the amount of time the paper circle with the enzyme catalase present on it, sowing an increase in enzyme activity. Therefore it can be hypothesised that there would be an effect on catalase activity from the increase in hydrogen peroxide concentration measured in time for the paper circle to ride to the top of the solution.

Enzymes are proteins that act as catalysts and help reactions take place. In short, enzymes reduce the energy needed for a reaction to take place, permitting a reaction to take place more easily. Some enzymes are shape specific and reduce the energy for certain reactions. Enzymes have unique folds of the amino acid chain which result in specifically shaped active sites (Frankova Fry 2013). When substrates fit in the active site of an enzyme, then it is able to catalyze the reaction. Enzyme activity is affected by the concentrations of the enzymes and substrate present (Worthington 2010). As the incidence of enzyme increases, the rate of reaction increases. Additionally, as the incidence of substrate increases so does the rate of reaction.

Enzymes owe their activity to the precise three-dimensional shape of their molecules. According to the 'lock-and-key' hypothesis, the substrates upon which an enzyme fit into a special slot in the enzyme