19. A (Primary polypeptide structure): The linear sequence of amino acids linked by peptide bonds is the primary structure of a protein. [HS.LS1-1]
20. B (Nucleotides (DNA)): Structure D represents the classic double helix shape of DNA, which is a polymer built from nucleotide monomers. [HS.LS1-6]
21. B (Disaccharide): Linking two monosaccharides (like glucose + glucose) forms maltose, a disaccharide. [HS.LS1-7]
High School Biology Key Page 1 of 2
Macro Master Answer Key Part IV & V
22. B (37°C): Graph 1 demonstrates peak enzyme activity (highest y-value) at human body temperature (37°C). [HS.LS1-1]
23. A (Denaturation): Extreme heat disrupts the hydrogen bonds holding the enzyme's secondary and tertiary tertiary folded structure together, causing permanent active site collapse. [HS.LS1-1]
24. A (Acidic (pH ~2)): Pepsin is an enzyme evolved to work in the highly acidic stomach, as shown by its curve peaking at pH 2 in Graph 2. [HS.LS1-1]
25. A (The pH denatures its structure): Trypsin's optimum pH is alkaline (pH 8). Extreme acidic pH changes disrupt ionic/hydrogen bonds, altering its active site structure. [HS.LS1-1]
26. A (The active site dynamically adjusts its shape slightly...): Unlike a completely rigid lock-and-key model, the induced fit model shows that enzyme binding involves subtle conformational shifts. [HS.LS1-1]
27. A (Sites saturated): Once all active sites are bound to substrate, rate hits Vmax and plateaus. [HS.LS1-1]
28. B (Proteins): Nearly all biological catalysts in living organisms are folded proteins. [HS.LS1-1]
29. B (ATP): Adenosine triphosphate provides immediate, convertible chemical energy. [HS.LS1-7]
30. A (Competitive): Competitive inhibitors physically block substrate access to active sites. [HS.LS1-1]
31. B (Phosphate head): The highly polar phosphate group can hydrogen-bond with water. [HS.LS1-6]
32. A (Messenger RNA): mRNA is single-stranded nucleic acid synthesized from a DNA template. [HS.LS1-1]
33. A (Lowering activation energy): Enzymes lower the initial energy barrier required to transition reactants. [HS.LS1-1]
34. B (Nitrogen): Proteins contain nitrogen (amine group) that general lipids lack entirely. [HS.LS1-6]
35. A (No double bonds): Straight tails allow saturated hydrocarbons to pack tightly together. [HS.LS1-6]
36. B (Weak hydrogen bonds): Hydrogen bonds are weak enough to allow separation during cell replication. [HS.LS1-1]
HS.LS1-1 (14 Questions) Proteins, enzymes, structural levels, DNA/RNA template function.
HS.LS1-6 (16 Questions) CHONP chemistry, carbohydrate, lipid, protein backbones & structure.
HS.LS1-7 (6 Questions) ATP currency, cellular fuel, dehydration synthesis/hydrolysis.
High School Biology Key Page 2 of 2
B. Amino acid
C. Monosaccharide
D. Glycerol
13. Which element is found in proteins but not usually in lipids or carbohydrates?
A. Carbon
B. Hydrogen
C. Oxygen
D. Nitrogen
14. What happens when an enzyme is denatured?
A. It works faster
B. It changes its products
C. It loses its functional shape
D. It turns into a lipid
15. Glycogen is an example of which macromolecule?
A. Lipid
B. Carbohydrate
C. Protein
D. Nucleic Acid
16. The "Induced Fit" model describes the interaction between:
A. DNA strands
B. Enzyme and substrate
C. Amino acid R-groups
D. Lipid tails
17. Which sugar is found in DNA?
A. Ribose
B. Glucose
C. Deoxyribose
D. Sucrose
18. Unsaturated fats have _____ in their fatty acid chains.
A. No double bonds
B. At least one double bond
C. Triple bonds only
D. No hydrogen atoms
19. Which of the following is a structural carbohydrate found in plants?
A. Starch
B. Chitin
C. Cellulose
D. Glycogen
20. Amino acids differ from each other based on their:
A. Amino group
B. Carboxyl group
C. R-group (side chain)
D. Hydrogen atom
21. What molecule is known as the energy currency of the cell?
A. Glucose
B. ATP
C. RNA
D. Hemoglobin
22. An enzyme's optimum pH is the pH at which it:
A. Denatures completely
B. Works most efficiently
C. Stops working
D. Changes into a substrate
23. Which macromolecule provides long-term energy storage and insulation?
A. Protein
B. Carbohydrate
C. Nucleic Acid
D. Lipid
24. Nitrogenous bases in DNA are held together by _____ bonds.
A. Ionic
B. Covalent
C. Hydrogen
D. Metallic
25. Which element is unique to nucleic acids among the four macromolecules?
A. Carbon
B. Nitrogen
C. Phosphorus
D. Hydrogen
26. Competitive inhibition occurs when a molecule binds to:
A. The active site
B. An allosteric site
C. The substrate
D. The product
27. Which level of protein structure is the sequence of amino acids?
A. Primary
B. Secondary
C. Tertiary
D. Quaternary
28. Disaccharides like sucrose are formed by joining two _____.
A. Fatty acids
B. Monosaccharides
C. Nucleotides
D. Amino acids
29. Enzymes are sensitive to which environmental factors?
A. Temperature only
B. pH only
C. Both Temperature and pH
D. Neither Temperature nor pH
30. Which lipid is a key component of animal cell membranes?
A. Triglyceride
B. Wax
C. Phospholipid
D. Cellulose
31. DNA and RNA are both types of:
A. Proteins
B. Nucleic Acids
C. Carbohydrates
D. Lipids
32. The part of the enzyme where the substrate binds is called the:
A. Allosteric site
B. Active site
C. Reaction site
D. Binding zone
33. Which of the following is a function of proteins?
A. Transporting oxygen
B. Providing structural support
C. Defending against disease
D. All of the above
34. A triglyceride is composed of one glycerol and three _____.
A. Amino acids
B. Nucleotides
C. Fatty acids
D. Glucose molecules
35. Which macromolecule is nonpolar and does not dissolve in water?
A. Carbohydrates
B. Proteins
C. Lipids
D. Nucleic Acids
End of Macro Concepts Test • Bio Lab Resources 2026
28. B: HS.LS1-7 - Disaccharides are formed through condensation of two monosaccharides.
29. C: HS.LS1-1 - Enzymes are sensitive to environmental shifts that break folding bonds.
30. C: HS.LS1-6 - Phospholipids are the structural units of the cellular boundary.
31. B: HS.LS1-1 - DNA and RNA are the two main information polymers.
32. B: HS.LS1-1 - The active site is the catalytic pocket where reactions occur.
33. D: HS.LS1-1 - Proteins handle immunity, transport, structure, and communication.
34. C: HS.LS1-6 - Triglycerides are composed of glycerol plus three fatty acid chains.
35. C: HS.LS1-6 - Nonpolar nature (hydrophobicity) makes lipids insoluble in water.
HS.LS1-1: Structure/Function
HS.LS1-6: Chemical Elements
HS.LS1-7: Energy transfer
Rationale Key • Bio Lab Resources 2026
