Chemical Reactions And Enzymes

This statement is true because all living organisms require energy to perform essential functions such as growth, reproduction, and metabolism. Energy is needed to carry out chemical reactions within cells, such as breaking down food molecules to release energy. Without a source of energy, organisms would not be able to survive. Therefore, it is necessary for every organism to have a source of energy to stay alive.

Enzymes are highly specific in nature, meaning they can only bind to certain substrates that have a complementary shape and chemical properties. This specificity allows enzymes to catalyze specific chemical reactions in the body. Therefore, the correct answer is "specific" as substrates bind to specific enzymes that can facilitate their conversion into products.

During chemical reactions, energy is either released or absorbed. When chemical bonds are formed, energy is released as the bonds are stabilized, resulting in a release of energy. On the other hand, when chemical bonds are broken, energy is absorbed from the surroundings to break the bonds, resulting in an absorption of energy. Therefore, the correct answer is released or absorbed.

One of the important chemical reactions in the body is when it enables the bloodstream to remove carbon dioxide. Carbon dioxide is a waste product produced by cells during metabolism, and it needs to be eliminated from the body to maintain proper pH balance. The respiratory system plays a crucial role in this process by exchanging oxygen for carbon dioxide in the lungs, which is then exhaled. This helps to prevent the buildup of carbon dioxide in the body, which can lead to respiratory acidosis and other health issues.

In enzyme-catalysed reactions, the reactants are referred to as substrates. Substrates are the molecules that bind to the active site of an enzyme and undergo a chemical reaction to form products. Enzymes act as catalysts by increasing the rate of these reactions without being consumed in the process. While enzymes are involved in the reaction, they are not the reactants themselves. Therefore, the correct answer is substrates.

Reactants are the elements or compounds that undergo a chemical reaction. They are the starting materials that are present before the reaction takes place. Reactants are transformed into products, which are the end result of the chemical reaction. Substrates, on the other hand, are specific reactants in enzyme-catalyzed reactions. Therefore, reactant is the correct answer as it refers to the substances that participate in a chemical reaction.

Chemical reactions are important to help the body maintain homeostasis. Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. Chemical reactions play a crucial role in regulating various physiological processes, such as metabolism, pH balance, and temperature control. These reactions help to break down nutrients, produce energy, eliminate waste products, and synthesize essential molecules. By maintaining homeostasis, the body ensures that its cells and organs function optimally, promoting overall health and well-being.

Enzymes are actually biological catalysts that speed up chemical reactions in cells rather than slowing them down. They are proteins that lower the activation energy required for a reaction to occur, making it easier for the reaction to take place. Therefore, the statement "Enzymes slow down chemical reactions that take place in cells" is incorrect.

Substrates and enzymes can be compared to a lock and key because just like a key is needed to unlock a lock, a substrate is needed to activate an enzyme. In this analogy, the bond represents the lock, and the substrate represents the key that fits perfectly into the lock (enzyme), allowing the bond to be broken or formed. This interaction between the substrate and enzyme is crucial for the enzyme to catalyze a specific reaction.

Chemical reactions that absorb energy do not occur spontaneously. In fact, these reactions require an input of energy in order to proceed. This is because the reactants have a higher energy level than the products, and energy needs to be added to the system to overcome this energy barrier. Once the energy is added, the reaction can occur and the products are formed. Therefore, the correct answer is false.

Reactants collide with energy in order to overcome the activation energy barrier and break the existing bonds. This allows the atoms or molecules to rearrange and form new bonds, resulting in the formation of products. The energy provided by the collision helps to destabilize the reactant molecules and initiate the chemical reaction.

A catalyst is a substance that speeds up the rate of a chemical reaction without being consumed in the process. It achieves this by providing an alternative pathway with a lower activation energy for the reaction to occur. By lowering the activation energy, the catalyst makes it easier for the reactant molecules to overcome the energy barrier and react, thus increasing the rate of the reaction. Therefore, the given answer "speeds up and lowers" accurately describes the effect of a catalyst on the rate of reaction and activation energy.