1.
A(n) ___ is a macromolecule made of many smaller molecules bonded together.
Correct Answer
A. Polymer
Explanation
A polymer is a macromolecule made of many smaller molecules bonded together. This means that it is composed of repeating units called monomers, which are chemically bonded to form a larger and more complex structure. Polymers can be found in various natural and synthetic materials, such as plastics, rubber, and proteins. They have a wide range of applications due to their versatility and ability to be tailored for specific purposes.
2.
___ are molecules composed of carbon, hydrogen, and oxygen, and they include sugars and starches.
Correct Answer
A. Carbohydrates
Explanation
Carbohydrates are molecules composed of carbon, hydrogen, and oxygen, and they include sugars and starches. They are an essential source of energy for the body and play a crucial role in various biological processes. Carbohydrates are classified into simple and complex carbohydrates based on their chemical structure. Simple carbohydrates, such as glucose and fructose, are easily broken down by the body for quick energy. Complex carbohydrates, such as starches and fibers, take longer to digest and provide a sustained release of energy. Overall, carbohydrates are an important macronutrient for the body's functioning.
3.
A(n) ___ is a molecular subunit of a polymer.
Correct Answer
B. Monomer
Explanation
A monomer is a molecular subunit of a polymer. Polymers are large molecules made up of repeating smaller units called monomers. These monomers join together through chemical reactions to form a polymer chain. Therefore, a monomer is an essential component in the formation of a polymer and is considered as a molecular subunit of a polymer.
4.
___ are non-polar macromolecules that include fats, oils, and cholesterol.
Correct Answer
D. Lipids
Explanation
Lipids are non-polar macromolecules that include fats, oils, and cholesterol. They are characterized by their insolubility in water and their ability to store energy. Lipids play important roles in the body, such as providing insulation and protection for organs, serving as a source of energy, and acting as structural components of cell membranes. They are also involved in various biological processes, including hormone production and cell signaling.
5.
___ are polymers that are made of amino acids.
Correct Answer
B. Proteins
Explanation
Proteins are polymers made up of amino acids. Amino acids are the building blocks of proteins, and they are joined together through peptide bonds to form long chains. These chains then fold into specific three-dimensional structures, giving proteins their unique functions. Carbohydrates, nucleic acids, and lipids are also polymers, but they are not made up of amino acids.
6.
___ are polymers made of nucleic acids.
Correct Answer
C. Nucleic acids
Explanation
Nucleic acids are polymers made of nucleotides. They are responsible for storing and transmitting genetic information in living organisms. There are two types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). DNA carries the genetic instructions for the development, functioning, and reproduction of all known living organisms, while RNA is involved in protein synthesis. Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen, while proteins are large biomolecules made of amino acids. Lipids are a diverse group of molecules that include fats, oils, and steroids.
7.
Molecules that contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur, and are used to build proteins are called ___.
Correct Answer
A. Amino acids
Explanation
Amino acids are molecules that contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. They are the building blocks of proteins, which are essential for various biological functions in the body. Amino acids are linked together in a specific sequence to form proteins, and their structure determines the function they perform. Therefore, amino acids are the correct answer in this context.
8.
Chains of carbon and hydrogen atoms that form a monomer of lipids are called ___.
Correct Answer
B. Fatty acids
Explanation
Chains of carbon and hydrogen atoms that form a monomer of lipids are called fatty acids. Lipids are organic molecules that are insoluble in water and are an essential component of cell membranes. Fatty acids are the building blocks of lipids and consist of a long hydrocarbon chain with a carboxyl group at one end. They can be either saturated or unsaturated depending on the presence of double bonds in the hydrocarbon chain.
9.
A(n) ___ changes substances into different substances by breaking and reforming chemical bonds.
Correct Answer
A. Chemical reaction
Explanation
A chemical reaction is a process that involves the breaking and formation of chemical bonds, resulting in the transformation of substances into different substances. During a chemical reaction, the reactants are converted into products through the rearrangement of atoms. This change occurs due to the breaking of existing bonds in the reactants and the formation of new bonds in the products. Therefore, a chemical reaction is the correct answer as it accurately describes the process of changing substances by breaking and reforming chemical bonds.
10.
The substance in a chemical reaction that is being changed is called a(n) ___.
Correct Answer
A. Reactant
Explanation
In a chemical reaction, the substance that undergoes a change is called a reactant. Reactants are the starting materials that are transformed into different substances during the reaction. They are consumed in the process and are necessary for the reaction to occur. In contrast, products are the substances that are formed as a result of the reaction. Catalysts are substances that speed up the reaction without being consumed themselves. Amino acids are organic compounds that serve as the building blocks of proteins and are not directly related to the concept of reactants in chemical reactions.
11.
The substance in a chemical reaction that is being produced is called a(n) ___.
Correct Answer
A. Product
Explanation
In a chemical reaction, the substance that is being produced is called a product. This is because a chemical reaction involves the transformation of reactants into new substances, which are the products of the reaction. Reactants are the substances that undergo the chemical changes, while catalysts are substances that speed up the reaction without being consumed themselves. Amino acids are organic compounds that are the building blocks of proteins and are not directly related to the concept of a product in chemical reactions.
12.
___ is the amount of energy that is needed to break a chemical bond.
Correct Answer
A. Bond energy
Explanation
Bond energy refers to the amount of energy required to break a chemical bond. It represents the strength of the bond and is measured in units of energy per mole. When a bond is broken, energy is absorbed, and when a bond is formed, energy is released. Bond energy is an important concept in chemistry as it helps to understand the stability and reactivity of molecules.
13.
___ is the amount of energy that is needed to start a chemical reaction.
Correct Answer
B. Activation energy
Explanation
Activation energy is the amount of energy required to initiate a chemical reaction. It is the energy barrier that must be overcome for the reaction to proceed. Activation energy is necessary because it allows reactant molecules to reach a transition state where bonds can be broken and new bonds can be formed. Without activation energy, reactions would not occur spontaneously. Bond energy refers to the strength of a chemical bond, exothermic energy refers to the energy released during a reaction, and stored energy refers to potential energy stored in chemical bonds or other forms.
14.
___ is reached when both reactants and products are made at the same rate.
Correct Answer
A. Equilibrium
Explanation
Equilibrium is reached when both reactants and products are made at the same rate. This means that the forward and reverse reactions occur at equal rates, resulting in a stable concentration of reactants and products. At equilibrium, the system is balanced, with no net change in the concentrations of reactants and products over time.
15.
A(n) ___ chemical reaction releases more energy than it absorbs.
Correct Answer
A. Exothermic
Explanation
An exothermic chemical reaction releases more energy than it absorbs. This means that the reactants have more energy than the products, resulting in the release of excess energy in the form of heat or light. In an exothermic reaction, the overall energy of the system decreases, making it energetically favorable. This is in contrast to an endothermic reaction, where the reaction absorbs more energy than it releases.
16.
A(n) ___ chemical reaction absorbs more energy than it releases .
Correct Answer
B. Endothermic
Explanation
An endothermic chemical reaction absorbs more energy than it releases. This means that the reactants have a lower energy level than the products, and energy is taken in from the surroundings to fuel the reaction. As a result, the surroundings become cooler.
17.
A(n) ___ is a substance that decreases the activation energy needed to start a chemical reaction, thereby increasing the rate of the reaction.
Correct Answer
A. Catalyst
Explanation
A catalyst is a substance that decreases the activation energy needed to start a chemical reaction, thereby increasing the rate of the reaction. It does this by providing an alternative pathway for the reaction to occur with lower energy requirements. This allows more reactant molecules to have sufficient energy to overcome the activation energy barrier and participate in the reaction. The catalyst itself is not consumed in the reaction and can be used repeatedly, making it an efficient and effective way to increase the rate of a chemical reaction.
18.
A(n) ___ is a specialized protein that acts as a catalyst for chemical reactions in living organisms.
Correct Answer
A. Enzyme
Explanation
An enzyme is a specialized protein that acts as a catalyst for chemical reactions in living organisms. Enzymes are responsible for speeding up the rate of these reactions by lowering the activation energy required. They do this by binding to specific molecules, known as substrates, and facilitating the conversion of these substrates into products. Enzymes are highly specific in their function and can be regulated to ensure that chemical reactions occur at the right time and in the right place within an organism.
19.
The specific reactants that an enzyme acts on are called ___.
Correct Answer
B. Substrates
Explanation
Enzymes are proteins that catalyze specific chemical reactions in living organisms. They bind to particular molecules, called substrates, and convert them into products. The substrates are the specific reactants on which the enzyme acts. Therefore, the correct answer is substrates.