Title: Important Biological Macromolecules
Course: Question Banks

Q: What makes it possible for carbon to form four covalent bonds with other atoms or molecules?
- It has an atomic number of four. (Incorrect. The atomic number for carbon is 6.)
- It has four electrons. (Carbon has 6 electrons.)
- It contains four electrons in its outer shell. (Correct. Carbon has only four electrons in its outer shell.)
A: It contains four electrons in its outer shell.

Q: What is responsible for the important role of carbon as the “foundation” element for molecules in living things?
- Carbon is a universal element. (Incorrect. Although carbon is a very common element, this is not the reason it is a foundation element for organic molecules.)
- Carbon can form ionic bond with organic molecules. (Incorrect. Carbon does not form ionic bond in organic molecules.)
- Carbon atoms can form multiple bonds with other carbon atoms or other elements. (Correct. Carbon is tetravalent and can form covalent bonds with carbon and other atoms.)
A: Carbon atoms can form multiple bonds with other carbon atoms or other elements.

Q: ________ is a carbohydrate.
- Glycerol (Incorrect. Glycerol is not a carbohydrate.)
- Insulin (Incorrect. Insulin is not a carbohydrate.)
- Cellulose (Correct. Cellulose is a major structural carbohydrate in plants.)
A: Cellulose

Q: What is the defining feature of carbohydrates?
- They always contain at least one nitrogen atom. (Incorrect. Carbohydrates may or may not contain a nitrogen side group (generally they do not).)
- They are always sweet to the taste. (Incorrect. Carbohydrates are not always sweet.)
- They are made up mostly of carbon, hydrogen, and oxygen. (Correct. This is where the name ‘carbo-hydrate’ comes from.)
A: They are made up mostly of carbon, hydrogen, and oxygen.

Q: A molecule of sucrose, or table sugar, is a ________.
- monosaccharide (Incorrect. A monosaccharide is a single sugar subunit.)
- polysaccharide (Incorrect. A polysaccharide contains numerous sugar subunits.)
- disaccharide (Correct. Sucrose is a compound made of glucose and fructose.)
A: disaccharide

Q: The most abundant natural biopolymer serves what function?
- Structural support in fungi (Incorrect. Chitin, which serves as structural support in fungi, is not the most abundant natural biopolymer.)
- Structural support in animals (Incorrect. This is not the function of the most abundant natural biopolymer.)
- Structural support in plants (Correct. Cellulose serves a structural role in plants and it is the most abundant natural biopolymer.)
A: Structural support in plants

Q: Animals store energy in the form of ________.
- starch (Incorrect. Plants store energy as starch.)
- glucose (Incorrect. Glucose is the basic carbohydrate form of energy in all organisms but is not used for energy storage.)
- glycogen (Correct. Animals store energy as glycogen.)
A: glycogen

Q: ________ store energy in the form of starch.
- Animals (Incorrect. Animals generally store energy as glycogen or fat.)
- Fungi (Incorrect. Fungi do not store energy as starch.)
- Plants (Correct. Plants store energy as starch.)
A: Plants

Q: Cellulose is so rigid because ________.
- it is composed of a modified monosaccharide with a rigid amino group (Incorrect. There is no special modification on the monosaccharide subunits of cellulose.)
- its disaccharide subunits are packed in a ring formation (Incorrect. Cellulose is not composed of disaccharide subunits.)
- its monosaccharide subunits are tightly packed as extended chains (Correct. Glucose is tightly packed into extended chains to make cellulose.)
A: its monosaccharide subunits are tightly packed as extended chains

Q: Lipids are typically ________.
- polar (Incorrect. Lipids are not polar.)
- either polar or nonpolar (Incorrect. Lipids are defined in only one way.)
- nonpolar (Correct. Lipids are overall nonpolar because of their non-polar bonds.)
A: nonpolar

Q: ________ are composed of a long chain of hydrocarbons to which a carboxyl group is attached.
- Waxes (Incorrect. Waxes are composed of long fatty acid chains.)
- Steroids (Incorrect. Steroids are composed of fused ring structures.)
- Fatty acids (Correct. Fatty acids have a long chain of hydrocarbons to which a carboxyl group is attached.)
A: Fatty acids

Q: Steroids are composed of ________.
- fused ring structures, which is typical for fats (Incorrect. Fats are not typically composed of fused ring structures.)
- long fatty acid chains, which is unusual for fats (Incorrect. Many fats have long fatty acid chains, but not steroids.)
- fused ring structures, which is unusual for fats (Correct. Steroids are composed of fused ring structures, which is atypical for the fats.)
A: fused ring structures, which is unusual for fats

Q: An important type of essential fatty acids are ________.
- trans fats (Incorrect. Trans fats are not required and are in fact probably harmful to human health.)
- saturated fatty acids (Incorrect. Most animal “fats” are saturated fatty acids and are synthesized by the body.)
- omega-3 fatty acids (Correct. Omega-3 fatty acids are required by humans but cannot be made by the body.)
A: omega-3 fatty acids

Q: The main lipid component of plasma membranes are ________.
- fats (Incorrect. Fats are not the major component of plasma membranes.)
- fatty acids (Incorrect. Fatty acids are not the major component of plasma membranes.)
- phospholipids (Correct. The major lipid component in plasma membranes are phospholipids.)
A: phospholipids

Q: The main purpose of ________ is to prevent water from sticking to a surface.
- phospholipids (Incorrect. The main purpose of phospholipids is to form plasma membranes.)
- steroids (Incorrect. Steroids do not prevent water from sticking to a surface.)
- waxes (Correct. Waxes prevent water from sticking to a surface.)
A: waxes

Q: A key function of fats is to ________.
- regulate temperature (Incorrect. Fats can serve as insulation but they do not regulate temperature directly.)
- form membranes (Incorrect. Fats do not form membranes.)
- store energy (Correct. Fats serve as high density energy storage.)
A: store energy

Q: Cholesterol is the precursor to ________, such as estrogen.
- digestive enzymes (Incorrect. Cholesterol is not an enzyme precursor.)
- cortisols (Incorrect. Cholesterol is not a precursor of cortisols.)
- steroid hormones (Correct. Cholesterol is a precursor to several steroid hormones such as estrogen and testosterone.)
A: steroid hormones

Q: Increased consumption of ________ may lead to heart disease.
- omega-6 fat (Incorrect. Omega-6 fat is an essential fatty acid.)
- omega-3 fat (Incorrect. Omega-3 fat is an essential fatty acid.)
- trans fat (Correct. Trans fats are artificially created and are thought to contribute to heart disease.)
A: trans fat

Q: Proteins are composed of linked ________.
- monosaccharides (Incorrect. Carbohydrates are composed of monosaccharides.)
- polymers (Incorrect. A polymer is simply something composed of repeating subunits bonded together.)
- amino acids (Correct. All proteins are polymers of amino acids.)
A: amino acids

Q: Protein ________ is critical to its function.
- size (Incorrect. The size of a protein is not critical to its function.)
- sequence (Incorrect. The sequence of amino acids making up a protein are important, but not the critical feature for function.)
- shape (Correct. The shape of a function controls what it does.)
A: shape

Q: The ________ of amino acids ultimately determine the protein’s shape, size, and function.
- sequence (Incorrect. Sequence alone will not determine all these factors of a protein.)
- number (Incorrect. Number alone will not determine all these factors of a protein.)
- sequence and number (Correct. Both sequence of amino acids, and the number of amino acids, determine a protein’s shape, size, and function.)
A: sequence and number

Q: Select the best description of a protein’s secondary structure.
- The unique 3D structure of a polypeptide (Incorrect. This is the tertiary structure.)
- The unique sequence of amino acids in a polypeptide chain. (Incorrect. This is the primary structure.)
- The local folding of a polypeptide. (Correct. This is the secondary structure of a protein.)
A: The local folding of a polypeptide.

Q: The ________ of proteins forms when several polypeptides interact into an overall structure.
- secondary structure (Incorrect. Secondary structure is the local folding of a polypeptide.)
- tertiary structure (Incorrect. Tertiary structure involves only a single polypeptide.)
- quaternary structure (Correct. Quaternary structure is the unique 3D structure of a protein composed of multiple polypeptide chains.)
A: quaternary structure

Q: Using the image below answer the following question. What does “3” indicate?
- Disulfide linkage (Incorrect. This is indicated by #4.)
- Hydrophobic interaction (Incorrect. This is indicated by #5.)
- Ionic bond (Incorrect. This is indicated by #1.)
- Polypeptide backbone (Incorrect. This is indicated by #2.)
- Hydrogen bond (Correct. #3 is a hydrogen bond.)
A: Hydrogen bond

Q: ________ increase the rate at which a chemical reaction occurs.
- Substrates (Incorrect. Substrates do not influence the rate of a chemical reaction.)
- Proteins (Incorrect. Proteins in general do not influence the rate of a chemical reaction.)
- Enzymes (Correct. Enzymes reduce the activation energy required for a reaction, increasing the rate at which it occurs.)
A: Enzymes

Q: An individual enzyme ________.
- can bind any number of substrates (Incorrect. Enzyme are not non-specific with regards to substrate.)
- is always a catabolic catalyst (Incorrect. Enzymes do not just catalyze catabolic reactions.)
- will generally bind a single substrate (Correct. Enzymes are usually specific to a single substrate but a few may bind a limited number of related molecules.)
A: will generally bind a single substrate

Q: A contractile protein works to ________.
- carry substances throughout the body (Incorrect. This is not the function of contractile proteins.)
- coordinate different body systems (Incorrect. This is not the function of contractile proteins.)
- effect muscle contractions (Correct. Contractile proteins play a role in muscle contractions.)
A: effect muscle contractions

Q: ________ work to aid in digestion of food.
- Hormones (Incorrect. This is not the function of a hormone.)
- Enzymes (Incorrect. This is not the function of an enzyme.)
- Amylase (Correct. Amylase is a digestive enzyme which works to aid in breakdown of food.)
A: Amylase

Q: Hormones are proteins that ________.
- aid in digestion of food (Incorrect. This is not the function of hormones.)
- cause catabolic reactions (Incorrect. This is not the function of hormones.)
- coordinate different body systems (Correct. Hormones coordinate different systems within the body.)
A: coordinate different body systems

Q: What is the defining feature of nucleic acids?
- For every carbon atom, they have two hydrogen atoms and one oxygen atom. (Incorrect. This is the defining feature of carbohydrates.)
- They contain nitrogen molecules and amino groups. (Incorrect. This is the defining feature of proteins.)
- They contain one or more nitrogenous bases, pentose sugars, and phosphates. (Correct. Nucleic acids are composed of pentose sugar backbones bound to nitrogenous bases and phosphate groups.)
A: They contain one or more nitrogenous bases, pentose sugars, and phosphates.

Q: A pentose sugar is the core of all ________.
- carbohydrates (Incorrect. Carbohydrates are not based on a pentose sugar.)
- proteins (Incorrect. Proteins are not based on a pentose sugar.)
- nucleic acids (Correct. All nucleic acids have a pentose sugar at the center of their nucleotide subunit.)
A: nucleic acids

Q: Nucleotide subunits are linked by a ________ bond.
- hydrogen (Incorrect. Hydrogen bonds are present within DNA strands but not linking nucleotide subunits.)
- disulfide (Incorrect. There are no disulfide bonds in nucleic acids.)
- phosphodiester (Correct. Phosphodiester bonds connect the nucleotide subunits making up nucleic acids.)
A: phosphodiester

Q: The pentose sugar ribose occurs in ________.
- DNA (Incorrect. The pentose sugar in DNA is deoxyribose.)
- either DNA or RNA (Incorrect. The pentose sugar in DNA is deoxyribose.)
- RNA (Correct. RNA uses the pentose sugar ribose.)
A: RNA

Q: A nucleotide of DNA may contain ________.
- deoxyribose, uracil, and a phosphate group (Incorrect. DNA does not use uracil.)
- ribose, uracil, and a phosphate group (Incorrect. This would be a nucleotide of RNA.)
- deoxyribose, thymine, and a phosphate group (Correct. DNA always has a phosphate group and deoxyribose and thymine is one of its pyrimidines.)
A: deoxyribose, thymine, and a phosphate group

Q: A nucleotide that contains ribose, uracil, and a phosphate group would be ________.
- DNA (Incorrect. DNA does not use uracil or ribose.)
- either DNA or RNA (Incorrect. DNA does not use uracil or ribose.)
- RNA (Correct. RNA always has a phosphate group and ribose and uracil is one of its pyrimidines.)
A: RNA

Q: DNA has ________.
- more functions than RNA (Incorrect. RNA does not have fewer functions than DNA.)
- the same amount of functions as RNA (Incorrect. They do not have the same number of functions.)
- fewer functions than RNA (Correct. RNA has three major functions while DNA has only one.)
A: fewer functions than RNA

Q: DNA contains ________, which RNA does not.
- uracil (Incorrect. Uracil is one of RNA’s pyrimidines.)
- adenine (Incorrect. Both DNA and RNA have adenine, a purine.)
- thymine (Correct. Thymine is one of DNA’s pyrimidines.)
A: thymine

Q: Nucleic acids, proteins, carbohydrates, and lipids are the four main classes of what?
- chemical functional groups (Incorrect. These are not chemical functional groups.)
- enzymes (Incorrect. These are not enzymes.)
- biological macromolecules (Correct. These are the four major biological macromolecules.)
A: biological macromolecules

Q: Which class of macromolecule generally contains the most phosphorus (P)?
- carbohydrates (Incorrect. Carbohydrates have relatively little phosphorus.)
- proteins (Incorrect. Proteins have the most nitrogen generally, not phosphorus.)
- nucleic acids (Correct. Nucleic acids have the most phosphorus.)
A: nucleic acids

Q: Which class of macromolecules has the most number of uses?
- lipids (Incorrect. Lipids do not have the most diverse number of uses.)
- carbohydrates (Incorrect. Carbohydrates do not have the most diverse number of uses.)
- nucleic acids (Incorrect. Nucleic acids do not have the most diverse number of uses.)
- proteins (Correct. Proteins have the most diverse uses of all the biological macromolecules.)
A: proteins