BICH 410 Exam 1 2025 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
1. Which group lists the four major classes of biomolecules?
A. Vitamins, minerals, water, salts
B. Carbohydrates, lipids, proteins, nucleic acids
C. Amino acids, fatty acids, monosaccharides, nucleotides
D. Hormones, enzymes, pigments, cofactors
Rationale: The four major biomolecular classes that form cellular structure and function are
carbs, lipids, proteins, and nucleic acids.
2. In biology, the term hierarchy most nearly means:
A. Random assortment of parts
B. Chemical equivalence
C. A group organized by rank or levels
D. A membrane-bound organelle
Rationale: “Hierarchy” refers to organization by levels (e.g., atoms → molecules → organelles →
cells → tissues).
3. Functional groups in organic molecules are:
A. Covalent bonds between monomers
B. Polymer backbones only
C. Reactive portions of molecules that determine chemical behavior
D. Types of sugars only
Rationale: Functional groups (–OH, –NH2, –COOH, etc.) provide chemical reactivity and
specificity.
4. The term linkages refers to:
A. Only ionic attractions in proteins
B. Bonding arrangements that connect atoms or monomers
C. Cellular organelles that link membranes
D. Enzyme active sites
Rationale: Linkages (ester, glycosidic, peptide, phosphodiester) join building blocks into
polymers.
5. Polymers are best described as:
A. Single small molecules used in metabolism
B. Large molecules composed of many repeating monomer units
C. Inorganic salts common in cells
, D. Enzymes that catalyze reactions
Rationale: Polymers (proteins, polysaccharides, nucleic acids) are chains of monomers.
6. Examples of inorganic precursors for biosynthesis include:
A. Glucose and ATP
B. Amino acids and nucleotides
C. Carbon dioxide, water, ammonia, nitrate
D. Cholesterol and triglycerides
Rationale: Small inorganic molecules like CO₂, H₂O, and inorganic nitrogen species serve as
starting substrates in biosynthesis.
7. Which of the following are common metabolites in central metabolism?
A. Glycogen and DNA only
B. Pyruvate, citrate, succinate, glyceraldehyde-3-phosphate
C. Cholesterol and bile salts
D. Insulin and glucagon
Rationale: These small molecules appear in glycolysis, the TCA cycle, and related pathways.
8. Which items are building blocks of macromolecules?
A. Vitamins and lipids
B. Nucleic acids and polysaccharides
C. Amino acids, nucleotides, monosaccharides, fatty acids, glycerol
D. Ribosomes and mitochondria
Rationale: Monomers (amino acids, nucleotides, monosaccharides, fatty acids + glycerol)
assemble into macromolecules.
9. Which are typical macromolecules found in cells?
A. Water, salts, hormones
B. Monosaccharides and free nucleotides
C. Proteins, nucleic acids, polysaccharides, lipids
D. ATP and GTP only
Rationale: Macromolecules are large biomolecules forming structures and catalyzing functions.
10. According to the list given, which element is the most abundant in the human body by number?
A. Carbon — 9.5%
B. Hydrogen — 63%
C. Oxygen — 25.5%
D. Nitrogen — 1.4%
Rationale: The provided breakdown indicates hydrogen as the largest fraction in this context.
11. Which element is listed as ~25.5% of the human body in your notes?
A. Carbon
B. Nitrogen
C. Oxygen
, D. Hydrogen
Rationale: Oxygen comprises a large portion of the body (as listed).
12. The bond energy of a chemical bond refers to:
A. The distance between bonded atoms
B. The energy required to break a bond and form neutral isolated atoms
C. The total kinetic energy of reactants
D. The activation energy of an enzyme-catalyzed reaction
Rationale: Bond energy quantifies the strength of a chemical bond; breaking it requires input of
energy.
13. Which formula set correctly matches the amine functional group examples?
A. ROH, ROR
B. RNH₂, R₂NH, R₃N
C. RCOOH, RCOOR
D. RCHO, RCOR
Rationale: Amines include primary (RNH₂), secondary (R₂NH), and tertiary (R₃N) forms.
14. The generic formula for an alcohol group is:
A. RSH
B. ROH
C. RCOOH
D. RNH₂
Rationale: Alcohols contain a hydroxyl (–OH) attached to an alkyl (R) group.
15. A thiol functional group is represented by:
A. ROR
B. RSH
C. RCONH₂
D. RCOOR
Rationale: Thiols contain a sulfhydryl (–SH) group; cysteine in proteins is a thiol.
16. An ether functional group has which general form?
A. RCOOH
B. RSH
C. R–O–R (ROR)
D. R–NH₂
Rationale: Ethers link two alkyl/aryl groups via an oxygen atom.
17. Which structure denotes an aldehyde?
A. RCOOH
B. R–CHO
C. RCOR
, D. R–SH
Rationale: Aldehydes have a carbonyl bonded to at least one hydrogen (–CHO).
18. A ketone has which general formula?
A. R–CHO
B. R–C(=O)–R (RCOR)
C. R–OH
D. R–COOH
Rationale: Ketones contain an internal carbonyl flanked by carbon groups.
19. Which is the general formula for a carboxylic acid?
A. ROR
B. RNH₂
C. RCOOH
D. RSH
Rationale: Carboxylic acids carry the –COOH functional group (carboxyl).
20. An ester linkage is represented as:
A. RNH₂
B. RCOOR
C. RSH
D. RCOSR
Rationale: Esters form from condensation between acids and alcohols (RCOOR).
21. A thioester is most similar to an ester but contains:
A. An extra oxygen atom
B. A sulfur replacing the oxygen in the linkage (RCOSR)
C. A phosphate group
D. An imine group
Rationale: Thioesters have sulfur (–S–) in place of the ester’s oxygen, important in metabolism
(e.g., acetyl-CoA).
22. Which describes an amide functional group?
A. ROH only
B. RCONH₂, RCONHR, RCONR₂
C. RSH only
D. RCOR only
Rationale: Amides link carboxyl-derived carbonyls to nitrogen (peptide bonds are amide
linkages).
23. An imine is commonly written as:
A. RCOOH
B. R–NH or R–N=R (contains a C=N double bond)
C. ROR
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
1. Which group lists the four major classes of biomolecules?
A. Vitamins, minerals, water, salts
B. Carbohydrates, lipids, proteins, nucleic acids
C. Amino acids, fatty acids, monosaccharides, nucleotides
D. Hormones, enzymes, pigments, cofactors
Rationale: The four major biomolecular classes that form cellular structure and function are
carbs, lipids, proteins, and nucleic acids.
2. In biology, the term hierarchy most nearly means:
A. Random assortment of parts
B. Chemical equivalence
C. A group organized by rank or levels
D. A membrane-bound organelle
Rationale: “Hierarchy” refers to organization by levels (e.g., atoms → molecules → organelles →
cells → tissues).
3. Functional groups in organic molecules are:
A. Covalent bonds between monomers
B. Polymer backbones only
C. Reactive portions of molecules that determine chemical behavior
D. Types of sugars only
Rationale: Functional groups (–OH, –NH2, –COOH, etc.) provide chemical reactivity and
specificity.
4. The term linkages refers to:
A. Only ionic attractions in proteins
B. Bonding arrangements that connect atoms or monomers
C. Cellular organelles that link membranes
D. Enzyme active sites
Rationale: Linkages (ester, glycosidic, peptide, phosphodiester) join building blocks into
polymers.
5. Polymers are best described as:
A. Single small molecules used in metabolism
B. Large molecules composed of many repeating monomer units
C. Inorganic salts common in cells
, D. Enzymes that catalyze reactions
Rationale: Polymers (proteins, polysaccharides, nucleic acids) are chains of monomers.
6. Examples of inorganic precursors for biosynthesis include:
A. Glucose and ATP
B. Amino acids and nucleotides
C. Carbon dioxide, water, ammonia, nitrate
D. Cholesterol and triglycerides
Rationale: Small inorganic molecules like CO₂, H₂O, and inorganic nitrogen species serve as
starting substrates in biosynthesis.
7. Which of the following are common metabolites in central metabolism?
A. Glycogen and DNA only
B. Pyruvate, citrate, succinate, glyceraldehyde-3-phosphate
C. Cholesterol and bile salts
D. Insulin and glucagon
Rationale: These small molecules appear in glycolysis, the TCA cycle, and related pathways.
8. Which items are building blocks of macromolecules?
A. Vitamins and lipids
B. Nucleic acids and polysaccharides
C. Amino acids, nucleotides, monosaccharides, fatty acids, glycerol
D. Ribosomes and mitochondria
Rationale: Monomers (amino acids, nucleotides, monosaccharides, fatty acids + glycerol)
assemble into macromolecules.
9. Which are typical macromolecules found in cells?
A. Water, salts, hormones
B. Monosaccharides and free nucleotides
C. Proteins, nucleic acids, polysaccharides, lipids
D. ATP and GTP only
Rationale: Macromolecules are large biomolecules forming structures and catalyzing functions.
10. According to the list given, which element is the most abundant in the human body by number?
A. Carbon — 9.5%
B. Hydrogen — 63%
C. Oxygen — 25.5%
D. Nitrogen — 1.4%
Rationale: The provided breakdown indicates hydrogen as the largest fraction in this context.
11. Which element is listed as ~25.5% of the human body in your notes?
A. Carbon
B. Nitrogen
C. Oxygen
, D. Hydrogen
Rationale: Oxygen comprises a large portion of the body (as listed).
12. The bond energy of a chemical bond refers to:
A. The distance between bonded atoms
B. The energy required to break a bond and form neutral isolated atoms
C. The total kinetic energy of reactants
D. The activation energy of an enzyme-catalyzed reaction
Rationale: Bond energy quantifies the strength of a chemical bond; breaking it requires input of
energy.
13. Which formula set correctly matches the amine functional group examples?
A. ROH, ROR
B. RNH₂, R₂NH, R₃N
C. RCOOH, RCOOR
D. RCHO, RCOR
Rationale: Amines include primary (RNH₂), secondary (R₂NH), and tertiary (R₃N) forms.
14. The generic formula for an alcohol group is:
A. RSH
B. ROH
C. RCOOH
D. RNH₂
Rationale: Alcohols contain a hydroxyl (–OH) attached to an alkyl (R) group.
15. A thiol functional group is represented by:
A. ROR
B. RSH
C. RCONH₂
D. RCOOR
Rationale: Thiols contain a sulfhydryl (–SH) group; cysteine in proteins is a thiol.
16. An ether functional group has which general form?
A. RCOOH
B. RSH
C. R–O–R (ROR)
D. R–NH₂
Rationale: Ethers link two alkyl/aryl groups via an oxygen atom.
17. Which structure denotes an aldehyde?
A. RCOOH
B. R–CHO
C. RCOR
, D. R–SH
Rationale: Aldehydes have a carbonyl bonded to at least one hydrogen (–CHO).
18. A ketone has which general formula?
A. R–CHO
B. R–C(=O)–R (RCOR)
C. R–OH
D. R–COOH
Rationale: Ketones contain an internal carbonyl flanked by carbon groups.
19. Which is the general formula for a carboxylic acid?
A. ROR
B. RNH₂
C. RCOOH
D. RSH
Rationale: Carboxylic acids carry the –COOH functional group (carboxyl).
20. An ester linkage is represented as:
A. RNH₂
B. RCOOR
C. RSH
D. RCOSR
Rationale: Esters form from condensation between acids and alcohols (RCOOR).
21. A thioester is most similar to an ester but contains:
A. An extra oxygen atom
B. A sulfur replacing the oxygen in the linkage (RCOSR)
C. A phosphate group
D. An imine group
Rationale: Thioesters have sulfur (–S–) in place of the ester’s oxygen, important in metabolism
(e.g., acetyl-CoA).
22. Which describes an amide functional group?
A. ROH only
B. RCONH₂, RCONHR, RCONR₂
C. RSH only
D. RCOR only
Rationale: Amides link carboxyl-derived carbonyls to nitrogen (peptide bonds are amide
linkages).
23. An imine is commonly written as:
A. RCOOH
B. R–NH or R–N=R (contains a C=N double bond)
C. ROR
