1.
The four main macromolecules are ___________, _____________, ___________ and ___________
Explanation
The four main macromolecules are DNA, proteins, lipids, and carbohydrates. These macromolecules are essential for the functioning of living organisms. DNA carries the genetic information and is responsible for transmitting hereditary traits. Proteins are involved in various biological processes and perform functions such as catalyzing chemical reactions, providing structure, and transporting molecules. Lipids are important for energy storage, insulation, and forming cell membranes. Carbohydrates are a major source of energy and also play a role in cell structure and signaling.
2.
How many different types of amino acids make up proteins?
Correct Answer
B. 20
Explanation
Proteins are made up of different types of amino acids. There are 20 different types of amino acids that make up proteins. Each amino acid has a unique structure and properties, which allows proteins to have diverse functions in the body. These amino acids are linked together in a specific order to form a protein chain, and the sequence of amino acids determines the protein's structure and function.
3.
Carbohydrates are composed of:
Correct Answer
A. Monosaccharides
Explanation
Carbohydrates are organic compounds that consist of carbon, hydrogen, and oxygen atoms. They are classified based on the number of sugar molecules they contain. Monosaccharides are the simplest form of carbohydrates and cannot be further broken down into smaller sugar molecules. They are the building blocks of more complex carbohydrates like disaccharides and polysaccharides. Therefore, monosaccharides are the correct answer as they are the basic units of carbohydrates.
4.
The molecule of DNA consists of two strands coiled together to form a ________ ________
Correct Answer
double helix
Explanation
The structure of DNA is composed of two strands that are twisted around each other to form a double helix. This twisted ladder-like shape allows the DNA molecule to be stable and compact while still maintaining the ability to store and transmit genetic information. The double helix structure is formed by the pairing of complementary nucleotide bases (adenine with thymine, and guanine with cytosine) between the two strands, creating a strong and efficient way to store and replicate genetic information.
5.
Each enzyme catalyses only one type of reaction.
Correct Answer
A. True
Explanation
Enzymes are highly specific biological catalysts that facilitate chemical reactions in living organisms. Each enzyme is designed to bind to a specific substrate and catalyze a specific reaction. This specificity is due to the unique shape and active site of each enzyme, which allows it to interact with only certain molecules. Therefore, it is true that each enzyme catalyzes only one type of reaction.
6.
The main source of energy for life on Earth is sunlight.
Correct Answer
A. True
Explanation
Sunlight is the main source of energy for life on Earth because it is responsible for photosynthesis, the process by which plants convert sunlight into chemical energy. This energy is then passed on to other organisms in the food chain. Additionally, sunlight provides warmth and light, which are essential for the survival and growth of living organisms.
7.
What letters are short for Adenosine Triphosphate?
Correct Answer
ATP
Explanation
ATP is the abbreviation for Adenosine Triphosphate. Adenosine Triphosphate is a molecule that stores and releases energy in cells. It is often referred to as the "energy currency" of the cell because it provides the energy needed for various cellular processes. The three phosphate groups in ATP are responsible for storing and releasing energy as they are broken and formed. Therefore, ATP is the correct abbreviation for Adenosine Triphosphate.
8.
Lipids are generally _______.
Correct Answer
A. Hydrophobic
Explanation
Lipids are generally hydrophobic because they consist of nonpolar molecules, such as fats and oils, which do not dissolve in water. This is due to their long hydrocarbon chains that repel water molecules. Lipids play important roles in the body, such as storing energy, insulating organs, and forming cell membranes.
9.
Glycerol has only ____ carbons.(how many)
Correct Answer
3
Explanation
Glycerol, also known as glycerin, has only 3 carbons. This is because glycerol is a trihydric alcohol molecule, meaning it contains three hydroxyl groups (-OH) attached to each of its three carbon atoms. Therefore, the correct answer is 3.
10.
What are the 3 structures of a nucleotide?(multiple answers)
Correct Answer(s)
A. 5 carbon sugar
B. Nitrogenous base
C. Phosphate group
Explanation
The three structures of a nucleotide are a 5 carbon sugar, a nitrogenous base, and a phosphate group. These three components make up the basic building blocks of nucleic acids, such as DNA and RNA. The 5 carbon sugar is usually either ribose or deoxyribose, the nitrogenous base can be adenine, guanine, cytosine, or thymine/uracil depending on the nucleic acid, and the phosphate group provides the necessary energy for cellular processes. The carboxyl group and amino acid base mentioned in the options are not part of a nucleotide structure.
11.
How many strands does DNA have?
Correct Answer(s)
2
Explanation
DNA, or deoxyribonucleic acid, is a double-stranded molecule that consists of two strands twisted around each other in a helical structure called a double helix. Each strand is made up of a long chain of nucleotides, which are the building blocks of DNA. The two strands are held together by hydrogen bonds between complementary nucleotide bases. Therefore, the correct answer is 2, as DNA has two strands.
12.
What are the nitrogenous bases of DNA?
Correct Answer(s)
A. Adenine
C. Thymine
D. Guanine
E. Cytosine
Explanation
The nitrogenous bases of DNA are Adenine, Thymine, Guanine, and Cytosine. These bases are the building blocks of DNA and are responsible for carrying genetic information. Adenine pairs with Thymine, and Guanine pairs with Cytosine, forming the base pairs that make up the DNA double helix structure. Uracil is a nitrogenous base found in RNA, not DNA.
13.
One DNA strand is complementary to the other, choose the correct ones below.(multiple answers)
Correct Answer(s)
C. A + T
D. G + C
Explanation
The correct answer is A + T, G + C. In DNA, the nucleotide bases always pair up in a specific way: adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C). This is known as complementary base pairing. Therefore, A always pairs with T, and G always pairs with C.
14.
What is the name of the process that joins monomers together to make polymers?
Correct Answer
E. Dehydration synthesis
Explanation
Dehydration synthesis is the correct answer because it is the process that joins monomers together to form polymers. During dehydration synthesis, a water molecule is removed from the monomers, allowing them to bond together and form a larger molecule. This process is also known as condensation reaction.
15.
In hydrolysis, __________________ , and in this process water is _________________________ .
Correct Answer
A. A polymer breaks up to form monomers ... consumed
Explanation
In hydrolysis, a polymer breaks up to form monomers. This means that the polymer is being broken down into smaller units called monomers. In this process, water is consumed, meaning that water is used up or utilized during the breakdown of the polymer into monomers.
16.
Every protein (polypeptide) has a free ________________ on one end and a free ___________________ on the other end.
Correct Answer
B. Amino group.....carboxyl group
Explanation
Proteins are made up of amino acids, which are linked together by peptide bonds. Each amino acid has an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end. The amino group of one amino acid forms a peptide bond with the carboxyl group of another amino acid, resulting in the formation of a polypeptide chain. Therefore, every protein has a free amino group on one end and a free carboxyl group on the other end.
17.
A polypeptide is the same as a protein.
Correct Answer
B. False
Explanation
A polypeptide is not the same as a protein. A polypeptide is a chain of amino acids, whereas a protein is a functional molecule made up of one or more polypeptides. Proteins often undergo post-translational modifications and folding to acquire their specific structure and function. Therefore, while all proteins are made up of polypeptides, not all polypeptides are proteins.
18.
A_______ is a polymer constructed from a set of just 20 kinds of monomers called Amino Acids?
Correct Answer
Protein
Explanation
Proteins are polymers made up of amino acids. Amino acids are the building blocks of proteins, and there are 20 different types of amino acids that can be combined in various sequences to form different proteins. Therefore, the correct answer is protein.
19.
How many amino acids are there?
Correct Answer
B. 20
Explanation
There are 20 amino acids. Amino acids are the building blocks of proteins and are essential for various biological processes. They are composed of an amino group, a carboxyl group, and a unique side chain. These side chains determine the properties and functions of each amino acid. There are 20 different side chains, resulting in 20 different amino acids that can be combined in different sequences to form proteins.
20.
What is a monomer?
Correct Answer
A. A single unit of macromolecules
Explanation
A monomer refers to a single unit of macromolecules. Macromolecules are large molecules made up of smaller subunits called monomers. These monomers can link together to form polymers through chemical reactions such as polymerization. Therefore, the correct answer is "A single unit of macromolecules."
21.
What is a polymer?
Correct Answer
B. Multiple units of macromolecules
Explanation
A polymer is a substance made up of multiple units of macromolecules. Macromolecules are large molecules made up of smaller units called monomers. When these monomers join together in a repeating pattern, they form a polymer. Polymers can be found in various forms, such as plastics, rubber, and fibers. They have a wide range of applications in industries like packaging, textiles, and construction.
22.
How do you get from a monomer to a polymer?
Correct Answer
C. Remove water
Explanation
To form a polymer from a monomer, the process of dehydration synthesis is used. This involves removing a water molecule from between two monomer units, which results in the formation of a covalent bond between them. By removing water, the monomers are able to join together and form a larger, more complex molecule known as a polymer. This process can be repeated multiple times, allowing for the formation of longer polymer chains.
23.
How do you get from a polymer to a monomer?
Correct Answer
A. Add water
Explanation
When water is added to a polymer, it undergoes a process called hydrolysis. In this process, the water molecules break the chemical bonds between the monomers that make up the polymer. As a result, the polymer is broken down into its individual monomer units. This is because water molecules provide the necessary energy to break the bonds, allowing the polymer to be converted back into its monomeric form.
24.
What are carbohydrates?
Correct Answer
C. Sugars, starches, etc..
Explanation
Carbohydrates are organic compounds that are made up of sugars, starches, and fibers. They are an essential source of energy for the body and are found in various foods such as fruits, vegetables, grains, and dairy products. Carbohydrates play a crucial role in providing fuel for the brain, muscles, and other organs, as well as aiding in digestion and maintaining overall health.
25.
What is the monomer of carbs?
Correct Answer
C. Monosaccharide
Explanation
Carbohydrates are composed of monosaccharides, which are the monomers or building blocks of carbs. Monosaccharides are simple sugars, such as glucose and fructose, that can be joined together through dehydration synthesis to form larger carbohydrate molecules. Nucleotides are the monomers of nucleic acids, amino acids are the monomers of proteins, and glycerol is a component of lipids. Therefore, the correct answer is monosaccharide.
26.
What are the 3 monosaccharides?
Correct Answer
C. Glucose, Fructose, Galactose
Explanation
The correct answer is glucose, fructose, and galactose. Monosaccharides are the simplest form of carbohydrates and cannot be broken down into smaller sugars. Glucose is the primary source of energy for the body, fructose is found in fruits and honey, and galactose is found in dairy products.
27.
What is the polymer of a carbohydrate?
Correct Answer
B. Disaccharide
Explanation
A carbohydrate is a macromolecule composed of carbon, hydrogen, and oxygen atoms. It is made up of monomers called monosaccharides. When two monosaccharides join together through a glycosidic bond, they form a disaccharide. Therefore, a disaccharide is the polymer of a carbohydrate. Phospholipid, DNA, and secondary structure are not polymers of carbohydrates.
28.
What holds 2 monosaccharides together?
Correct Answer
A. Glycosidic linkage
Explanation
A glycosidic linkage is the bond that holds two monosaccharides together. Monosaccharides are simple sugars, and when they combine, they form disaccharides or polysaccharides. The glycosidic linkage is formed through a dehydration reaction, where a hydroxyl group from one monosaccharide combines with a hydrogen atom from another monosaccharide, resulting in the formation of a covalent bond. This linkage is important in the formation of carbohydrates, such as sucrose and cellulose, which are essential for energy storage and structural support in living organisms.
29.
What does glucose+fructose give you?
Correct Answer
B. Sucrose
Explanation
Glucose and fructose combine to form sucrose. Sucrose is a disaccharide made up of one glucose molecule and one fructose molecule. This combination occurs through a condensation reaction, where a molecule of water is eliminated, resulting in the formation of a new bond between the two monosaccharides. Sucrose is commonly found in table sugar and is widely used as a sweetener.
30.
What is cellulose used for?
Correct Answer
C. Plant cell walls
Explanation
Cellulose is a complex carbohydrate that is the main component of plant cell walls. It provides structural support and rigidity to plant cells, allowing them to maintain their shape and withstand external pressure. Cellulose is not used in fungi and arthropod exoskeletons, animal skeletons, or cell membranes. Therefore, the correct answer is that cellulose is used for plant cell walls.
31.
What is chitin used for?
Correct Answer
A. Fungi and arthropod exoskeletons
Explanation
Chitin is a substance that is primarily found in the cell walls of fungi and the exoskeletons of arthropods. It provides structural support and protection to these organisms. Chitin is a tough and flexible material, making it ideal for forming the rigid exoskeletons of insects, crustaceans, and other arthropods. It also plays a role in the cell walls of fungi, providing strength and stability to their structures. Therefore, chitin is mainly used in the construction of fungi and arthropod exoskeletons.
32.
What are lipids?
Correct Answer
D. Fats, oils, etc...
Explanation
The correct answer is "Fats, oils, etc..." because lipids are a group of molecules that include fats, oils, and other similar compounds. They are hydrophobic and insoluble in water, and they play important roles in energy storage, insulation, and cell membrane structure.
33.
Name a quality of saturated fats
Correct Answer
C. Solid at room temp.
Explanation
Saturated fats are known for being solid at room temperature. This is because they have a higher melting point compared to unsaturated fats. Saturated fats have a straight molecular structure with single bonds, which allows them to pack tightly together and form a solid state. In contrast, unsaturated fats have double bonds, causing kinks in their structure, and resulting in a liquid state at room temperature.
34.
Name a quality of unsaturated fats
Correct Answer
D. Liquid at room temp.
Explanation
Unsaturated fats are characterized by their liquid state at room temperature. Unlike saturated fats, which have no double bonds in their carbon chains and are solid at room temperature, unsaturated fats have one or more double bonds in their carbon chains, causing them to be liquid at room temperature. This property makes them more beneficial for health as they are less likely to contribute to the buildup of plaque in arteries and can help lower bad cholesterol levels.
35.
What does it mean to denature a protein?
Correct Answer
B. Permanently change conformation
Explanation
To denature a protein means to permanently change its conformation. This can occur due to various factors such as heat, pH changes, or exposure to certain chemicals. When a protein is denatured, its secondary, tertiary, and quaternary structures are disrupted, leading to loss of its functional properties. The protein's shape is altered, causing it to unfold and lose its specific three-dimensional structure. This can result in the protein becoming inactive or losing its ability to perform its normal biological functions.
36.
How do you denature a protein?
Correct Answer
D. All of the above
Explanation
Proteins can be denatured through various methods, including intense heat, pH change, and altering salt concentration. Heat disrupts the weak bonds that hold the protein structure together, causing it to unfold and lose its function. pH change can alter the charges on the protein, affecting its shape and stability. Changing salt concentration can disrupt the ionic interactions between amino acids, leading to protein denaturation. Therefore, all of the above methods can denature a protein.
37.
Is DNA double or single stranded?
Correct Answer
A. Double
Explanation
DNA is double stranded because it consists of two strands that are twisted together in a double helix structure. Each strand is made up of a sequence of nucleotides, which are the building blocks of DNA. The two strands are held together by hydrogen bonds between complementary nucleotides. This double stranded structure is important for DNA replication and for the storage and transmission of genetic information.
38.
What does antiparallel refer to?
Correct Answer
A. DNA going from 5' to 3' on one side and 3' to 5' on the other side
Explanation
Antiparallel refers to the orientation of the two strands in a DNA molecule. In an antiparallel arrangement, one strand runs in the 5' to 3' direction, while the other strand runs in the opposite direction, from 3' to 5'. This arrangement is important because it allows for the complementary base pairing between the two strands, where adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C). This complementary base pairing is crucial for DNA replication and the synthesis of RNA during transcription.
39.
What does a double helix refer to?
Correct Answer
A. Twisted ladder of DNA
Explanation
A double helix refers to the twisted ladder structure of DNA. This structure consists of two strands that are twisted around each other, forming a helix shape. The strands are held together by hydrogen bonds between complementary base pairs (adenine with thymine, and guanine with cytosine). The double helix structure of DNA is essential for its stability and for the accurate transmission of genetic information during DNA replication and protein synthesis.
40.
What compliments A?
Correct Answer
A. T
41.
What compliments C?
Correct Answer
C. G
42.
Organisms are made up of chemicals that are based mostly on the element _________________.
Correct Answer
B. Carbon
Explanation
Organisms are made up of chemicals that are based mostly on the element carbon. Carbon is a fundamental element for life as it has the unique ability to form stable covalent bonds with other carbon atoms and with other elements. This allows carbon to form the complex and diverse organic molecules that are essential for the structure and function of living organisms. Carbon is the backbone of biological macromolecules such as proteins, nucleic acids, carbohydrates, and lipids, which are vital for life processes such as growth, reproduction, and metabolism.
43.
______________ compounds are compounds that contain carbon.
Correct Answer
C. Organic
Explanation
Organic compounds are compounds that contain carbon. This is because organic chemistry is the branch of chemistry that deals with the study of carbon-based compounds. Carbon is unique in its ability to form a wide variety of complex molecules due to its ability to form strong covalent bonds with other elements. Therefore, any compound that contains carbon is considered organic. Carbonic, regular, and isomers do not specifically refer to compounds that contain carbon, so they are not the correct answers.
44.
The branch of chemistry that specializes in the study of carbon compounds is called ________________________.
Correct Answer
D. Organic Chemistry
Explanation
Organic chemistry is the branch of chemistry that focuses on the study of carbon compounds. Carbon is unique in its ability to form a wide variety of compounds due to its bonding properties. Organic chemistry explores the structure, properties, composition, reactions, and synthesis of carbon-based compounds, including hydrocarbons and their derivatives. This field plays a crucial role in understanding and developing materials, medicines, polymers, dyes, and many other important substances.
45.
The key to carbon's versatility is due to its electron configurations. It has ______ valence electrons that makes it tend to form _________ bonds with other atoms by ____________ its elections with other atoms. This sharing may include single or double bonds.
Correct Answer
B. 4; covalent; sharing
Explanation
Carbon has 4 valence electrons, which allows it to form covalent bonds with other atoms by sharing its electrons. Covalent bonds involve the sharing of electrons between atoms. This sharing of electrons can result in the formation of single or double bonds.
46.
Carbon skeletons may vary in
Correct Answer
E. All of the above
Explanation
The carbon skeletons in organic compounds can vary in length, branching, presence of double bonds, and formation of rings. This means that the carbon atoms can be arranged in different ways, resulting in different structures and properties of the compounds. Therefore, all of the given options (length, branching, double bonds, and rings) are correct as they represent the possible variations in carbon skeletons.
47.
___________________ are organic molecules that consist of only C and H atoms.
Correct Answer
Hydrocarbon
Explanation
Hydrocarbons are organic molecules that consist of only carbon and hydrogen atoms. They are the simplest form of organic compounds and are widely found in nature. Hydrocarbons are the main components of fossil fuels such as petroleum and natural gas. They can exist in different forms, including alkanes, alkenes, and alkynes, depending on the type of carbon-carbon bonds present. Due to their high energy content, hydrocarbons are important sources of fuel and are used in various industries for the production of plastics, solvents, and other chemicals.
48.
Hydrocarbon is hydrophillic
Correct Answer
A. False
Explanation
Hydrocarbons are generally hydrophobic, meaning they do not mix or dissolve in water. This is because hydrocarbons are nonpolar molecules, while water is a polar molecule. Polar molecules are attracted to other polar molecules, while nonpolar molecules are not attracted to polar molecules. Therefore, hydrocarbons tend to repel water and are considered hydrophobic rather than hydrophilic.
49.
Is hydrocarbon soluble in water?
Correct Answer
A. No
Explanation
Hydrocarbons are nonpolar molecules, meaning they lack a charge and do not have the ability to form hydrogen bonds with water molecules. Since water is a polar molecule, it is not able to dissolve hydrocarbons. Therefore, hydrocarbons are generally insoluble in water.
50.
_____________ are compounds that have the same number of atoms of the same elements but different structures and hence different properties.
Correct Answer
A. Isomers
Explanation
Isomers are compounds that have the same number of atoms of the same elements but different structures and hence different properties. Isomers can have different arrangements of atoms or different spatial orientations, resulting in variations in their chemical and physical properties. This allows isomers to have different reactivity, boiling points, melting points, and other characteristics. Therefore, isomers are compounds with identical chemical formulas but distinct structural arrangements.