GCSE: Trivia Quiz On Enzymes! Test

The active site refers to the specific region in an enzyme molecule where a substrate molecule binds and undergoes a chemical reaction. This site has a unique shape and chemical properties that allow it to specifically recognize and bind to the substrate. The binding of the substrate to the active site induces a conformational change in the enzyme, facilitating the catalysis of the reaction. The active site is crucial for the enzyme's function and specificity, as it determines which substrates can bind and be transformed by the enzyme.

Proteins are a type of compound that can act as enzymes. Enzymes are specialized proteins that catalyze chemical reactions in living organisms. They play a crucial role in various biological processes by speeding up the rate of reactions. While carbohydrates and lipids are also important biomolecules, they do not have the same catalytic properties as proteins and are not typically classified as enzymes. Therefore, the correct answer is protein.

Amino acids are the building blocks of proteins, and enzymes are a type of protein. Enzymes play a crucial role in catalyzing biochemical reactions in living organisms. They help speed up these reactions by lowering the activation energy required for the reaction to occur. Therefore, amino acids are the component parts of enzymes, making them the correct answer. Glucose and starch are carbohydrates and not directly related to enzymes.

Protease is an enzyme responsible for breaking down proteins. It is produced in various parts of the digestive system to aid in the digestion of proteins. However, it is not produced in the mouth. The mouth primarily produces amylase, an enzyme that helps break down carbohydrates. Protease production begins in the stomach, where it is secreted by the gastric glands. It continues to be produced in the small intestine, where it is released by the pancreas and helps further break down proteins.

Mitochondria are the powerhouse of the cell and are responsible for producing energy in the form of ATP. Glucose is the main source of fuel for cellular respiration, and it enters the mitochondria through a process called glycolysis. Oxygen is required for the final step of cellular respiration, which is the electron transport chain. It acts as the final electron acceptor, allowing the production of ATP to occur. Therefore, both glucose and oxygen are substances that move into mitochondria for energy production.

An increase in the duration of the reaction does not affect the initial rate of an enzyme-controlled reaction. The initial rate of a reaction is determined by the concentration of reactants, including the substrate. It is the rate at which the reaction occurs at the beginning, before any significant amount of product has been formed. Increasing the duration of the reaction may affect the overall rate of the reaction, but it does not impact the initial rate.

This statement tells us that the type of inhibitor molecule involved in this reaction is one that has the same shape as the substrate. This suggests that the inhibitor molecule can bind to the active site of the enzyme because it fits into the active site just like the substrate does. This type of inhibition is known as competitive inhibition, where the inhibitor and substrate compete for the same binding site on the enzyme.

When the temperature of a solution increases, the kinetic energy of the molecules also increases. This leads to more frequent and energetic collisions between the enzyme and its substrate. These collisions are necessary for the enzyme to bind to its substrate and catalyze a reaction. Therefore, an increase in temperature increases the likelihood of successful collisions between the enzyme and substrate, resulting in a higher reaction rate.

When the amount of enzyme is doubled, it means that there are more enzyme molecules available to catalyze the reaction. Enzymes are catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur. Therefore, when the amount of enzyme is doubled, there are more active sites available for substrate binding, resulting in an increased rate of reaction. Thus, the reaction proceeds twice as quickly.

A denatured enzyme refers to an enzyme whose active site has been altered in shape, rendering it unable to catalyze a reaction. This change in shape is usually caused by extreme conditions such as high temperatures or changes in pH. Once an enzyme is denatured, it loses its ability to bind to its substrate and catalyze the reaction it normally facilitates. Therefore, the correct answer is "One with an active site of the wrong shape."

The correct answer is "It increases, levels off then decreases." This is because the rate of an enzyme-controlled reaction typically follows a specific pattern over time. Initially, as the concentration of substrate increases, the rate of the reaction also increases. However, as the concentration of substrate continues to increase, the rate of the reaction eventually levels off and reaches a maximum point. This is because all the enzyme molecules are fully saturated with substrate and are working at their maximum capacity. Finally, if the concentration of substrate becomes excessive, the rate of the reaction may start to decrease due to factors such as enzyme denaturation or inhibition.

Amylase is an enzyme that breaks down starch into simple sugars. When iodine solution is added to a suspension of starch, it forms a complex with the starch molecules, resulting in a black color. However, when amylase is added, it catalyzes the breakdown of starch into simple sugars, preventing the formation of the complex with iodine and causing the suspension to lose its black color.

Sperm cells contain the most mitochondria compared to the other cell types listed. Mitochondria are responsible for producing energy in cells, and sperm cells require a high amount of energy for their movement. The abundance of mitochondria in sperm cells allows them to generate the necessary energy to swim towards the egg for fertilization.

Isomerase is the correct answer because it is an enzyme that can convert one form of a molecule into another form. In the context of sweet food, isomerase can convert glucose into fructose, which is a sweeter form of sugar. This process is commonly used in the food industry to enhance the sweetness of certain products. Amylase and lipase are not involved in this specific process of making sweet food taste even sweeter.

Biological washing powders contain enzymes, which are biological catalysts that help break down stains and dirt. These enzymes are effective at lower temperatures, allowing the washing to occur effectively even without the need for high heat. This is beneficial as it saves energy and prevents damage to delicate fabrics that may be sensitive to high temperatures. Therefore, the presence of enzymes in biological washing powders allows washing to occur effectively at lower temperatures.

The best explanation for the finding that amylase taken from the mouth does not work in a solution of stomach juices but works in a solution of small intestine juices is that mouth juices have the same pH as small intestine juices. Amylase is an enzyme that functions optimally at a specific pH level. Since the amylase from the mouth works in the small intestine, it suggests that the pH of the mouth juices and small intestine juices are similar, allowing the amylase to function properly. The fact that it does not work in the stomach juices, which are acidic, further supports this explanation.

When an enzyme-controlled reaction goes to completion, it means that all the available substrate has been converted into products. Adding extra substrate after the reaction has finished would create more substrate molecules for the enzyme to act upon. Since the enzyme is still present and active, it can continue to catalyze the reaction at its maximum rate. Therefore, the rate of reaction would increase when extra substrate is added after the reaction has finished.

Amylase is an enzyme that helps in the breakdown of carbohydrates. It is produced in the mouth by the salivary glands and in the small intestine by the pancreas. In the mouth, amylase starts the digestion process by breaking down starches into smaller molecules. In the small intestine, amylase continues to break down carbohydrates into simpler sugars that can be absorbed by the body. Therefore, both the mouth and small intestine are correct answers for the production of amylase.

Protease and lipase are enzymes that can cause a fall in the pH of a solution. Protease is responsible for breaking down proteins into smaller peptides and amino acids, which releases hydrogen ions and lowers the pH. Lipase, on the other hand, breaks down lipids into fatty acids and glycerol, also releasing hydrogen ions and decreasing the pH of the solution. Therefore, both protease and lipase can contribute to a decrease in pH when they are active.