Page 1 AP Biology: 2026 Exam Review
AP BIOLOGY EXAM REVIEW GUIDE
“The price of success is hard work, dedication to the job at hand, and the determination that
whether we win or lose, we have applied the best of ourselves to the task at hand.”
, Page 2 AP Biology: 2026 Exam Review
CONCEPT 1 - BIOCHEMISTRY
1. CHNOPS- most common elements in all living matter
2. Bonds- ionic (transfer electrons), covalent (sharing- polar/unequal sharing and non-polar/equal sharing),
hydrogen (weak bonds between hydrogen and negatively charged items), hydrophobic interactions (how
non-polar compounds congregate together- lipids)
3. pH
a. acid-base/ 0-14, # of H ions determines scale; logarithmic- pH 3 = 10-3 = 1/1000
b. blood- 7.4, stomach- 2, small intestine- 8; enzymes are specific to pH
4. Water properties- polarity, cohesion(attraction to other water molecules), adhesion (attraction to other
charged compounds) low density when frozen, versatile solvent, high heat of fusion/vaporization;
surface tension
5. Organic molecules - monomers are simplest form of all; monomers join together via dehydration synthesis
(loss of water) to make polymers; polymers are broken down via hydrolysis (input of water)
a. Carbohydrates- CHO 1:2:1 ratio, monomer= monosaccharides, 2=disaccharides, 3 or more=
polysaccharides
• Used for energy (cell respiration)
• Examples
(1) glucose- immediate energy to make ATP
(2) starch- stored energy in plants
(3) glycogen- stored energy in animals (stored in liver)
(4) cellulose- plant cell wall
b. Lipids – C, H, O (not a 1:2:1 ratio) *P only in phospholipids
(1) fats, waxes, oils and sterols
(2) Saturated fats have single bonds between carbons, unsaturated fats have at least one
double bond between carbons (kinky); plants make polyunsaturated; animals make
monounsaturated
(3) Phospholipids make up cell membranes (double layer) and are amphipathic- hydrophilic and
hydrophobic
(4) Uses- in all membranes; stored energy, protection, insulation, myelin sheath of nerves
c. Proteins- C, H, O, N (may have other elements in R group)
(1) Monomer- amino acids (20 total types), 2=dipeptide, 3 or more= polypeptide
(2) Parts of amino acid= carboxyl group (COOH) on one end, amino group on the other end
(NH2), central carbon and variable R group (can be hydrophobic or hydrophilic) which
determines chemical properties.
(3) Protein Folding- shape determines function; primary= a.a. chain; secondary= beta pleated
sheet or alpha helix( hydrogen bonds); tertiary=globular; folds in on itself (disulfide bridges,
hydrogen bonds, hydrophobic interactions; ionic bonding); quartenary= more than one
polypeptide.
(4) Uses- protein carriers in cell membrane, antibodies, hemoglobin, enzymes, most hormones
, Page 3 AP Biology: 2026 Exam Review
d. Nucleic acids – C, H, O, N, P
(1) Monomer= nucleotide, 2 = dinucleotide, 2 or more polynucleotide
(2) Nucleotide made up of sugar, phosphate and base
(3) Used to store genetic information
(4) DNA is double stranded, has deoxyribose, A, G, C, T
(5) RNA is single stranded, has ribose, A, G, C, U
(6) mRNA- copies genetic message; rRNA- attaches mRNA and makes up ribosomes (most
common);tRNA- carries amino acids; DNA- carries genetic code
6. Enzymes
a. Biological catalysts (made of protein) that speed up rate of chemical reactions by lowering
activation energy required for reaction to occur
b. Enzyme has active site (exposed R groups) where reaction occurs
c. Enzymes can break down substance (catabolic reaction) or build up substances (anabolic)
d. Enzyme/substrate complex is formed
e. Substrate is what enzyme acts on
f. Rate is determined by collisions between substrate and enzyme
g. Ends in –ase, named after substrate often
h. Enzyme is specific to substrate; the substrate must be complementary to the surface properties
(shape and charge) of the active site (which is made up of R groups with specific chemistry, i.e.
hydrophobic).
i. Enzyme rate is affected by:
• pH (optimal for each enzyme),
• temperature (optimal for each enzyme but in general increased temp means increased
collisions so rate goes up initially; too much heat can denature enzyme), enzyme
concentration (more enzyme faster rate or vice versa)
• substrate concentration (more substrate faster rate; vmax is fastest enzyme can work when
saturated)
j. Inhibition-competitive inhibition (something competes for active site; can be overcome with more
substrate)
k. Non-competitive inhibition- attaches at allosteric site and changes shape of enzyme so it is not
functional; can not be overcome with more substrate
l. Coenzymes (organic; NAD and vitamin B etc.) and cofactors (inorganic; zinc, magnesium etc.)
interact with enzymes to put them into the right structure to do work.
Vocabulary
active site denaturation non-polar molecule
allosteric site disaccharide nucleic acid
amino acid hydrogen bond nucleotide
amphipathic hydrophilic organic molecule
anabolic hydrophobic peptide bond
carbohydrate ion polar molecule
carbon lipid polymer
catabolic macromolecule protein
catalyst monomer substrate
coenzyme monosaccharide water
, Page 4 AP Biology: 2026 Exam Review
Thinking Practice
1. If the following molecules were to undergo a dehydration synthesis reaction, what molecules would
result? Circle the parts of each amino acid that will interact and draw the resulting molecule.
The OH from amino acid 1 and the H from amino acid two combine to form water in dehydration synthesis.
2. Construct a bar graph that displays the relative amounts of hydrogen, carbon, oxygen, and nitrogen in
each of the four types of macromolecules (carbohydrates, lipids, proteins, nucleic acids).
carbohydrates: hydrogen=2; oxygen=1; carbon=1; nitrogen=0
lipids: hydrogen=1; oxygen=1; carbon=1; nitrogen=0
proteins: hydrogen=2; oxygen=1; carbon=1; nitrogen=1
nucleic acids: hydrogen=1; oxygen=1; carbon=1; nitrogen=1
3. Describe the relationship between substrate concentration and reaction rate shown in the graph below and
propose an explanation for it.:
J curve/exponential growth until it reaches the maximum, then it levels off. The enzyme concentration is
constant and as more substrate is added the enzyme becomes saturated with substrate reaching a maximum
rate of reaction, leveling off.
AP BIOLOGY EXAM REVIEW GUIDE
“The price of success is hard work, dedication to the job at hand, and the determination that
whether we win or lose, we have applied the best of ourselves to the task at hand.”
, Page 2 AP Biology: 2026 Exam Review
CONCEPT 1 - BIOCHEMISTRY
1. CHNOPS- most common elements in all living matter
2. Bonds- ionic (transfer electrons), covalent (sharing- polar/unequal sharing and non-polar/equal sharing),
hydrogen (weak bonds between hydrogen and negatively charged items), hydrophobic interactions (how
non-polar compounds congregate together- lipids)
3. pH
a. acid-base/ 0-14, # of H ions determines scale; logarithmic- pH 3 = 10-3 = 1/1000
b. blood- 7.4, stomach- 2, small intestine- 8; enzymes are specific to pH
4. Water properties- polarity, cohesion(attraction to other water molecules), adhesion (attraction to other
charged compounds) low density when frozen, versatile solvent, high heat of fusion/vaporization;
surface tension
5. Organic molecules - monomers are simplest form of all; monomers join together via dehydration synthesis
(loss of water) to make polymers; polymers are broken down via hydrolysis (input of water)
a. Carbohydrates- CHO 1:2:1 ratio, monomer= monosaccharides, 2=disaccharides, 3 or more=
polysaccharides
• Used for energy (cell respiration)
• Examples
(1) glucose- immediate energy to make ATP
(2) starch- stored energy in plants
(3) glycogen- stored energy in animals (stored in liver)
(4) cellulose- plant cell wall
b. Lipids – C, H, O (not a 1:2:1 ratio) *P only in phospholipids
(1) fats, waxes, oils and sterols
(2) Saturated fats have single bonds between carbons, unsaturated fats have at least one
double bond between carbons (kinky); plants make polyunsaturated; animals make
monounsaturated
(3) Phospholipids make up cell membranes (double layer) and are amphipathic- hydrophilic and
hydrophobic
(4) Uses- in all membranes; stored energy, protection, insulation, myelin sheath of nerves
c. Proteins- C, H, O, N (may have other elements in R group)
(1) Monomer- amino acids (20 total types), 2=dipeptide, 3 or more= polypeptide
(2) Parts of amino acid= carboxyl group (COOH) on one end, amino group on the other end
(NH2), central carbon and variable R group (can be hydrophobic or hydrophilic) which
determines chemical properties.
(3) Protein Folding- shape determines function; primary= a.a. chain; secondary= beta pleated
sheet or alpha helix( hydrogen bonds); tertiary=globular; folds in on itself (disulfide bridges,
hydrogen bonds, hydrophobic interactions; ionic bonding); quartenary= more than one
polypeptide.
(4) Uses- protein carriers in cell membrane, antibodies, hemoglobin, enzymes, most hormones
, Page 3 AP Biology: 2026 Exam Review
d. Nucleic acids – C, H, O, N, P
(1) Monomer= nucleotide, 2 = dinucleotide, 2 or more polynucleotide
(2) Nucleotide made up of sugar, phosphate and base
(3) Used to store genetic information
(4) DNA is double stranded, has deoxyribose, A, G, C, T
(5) RNA is single stranded, has ribose, A, G, C, U
(6) mRNA- copies genetic message; rRNA- attaches mRNA and makes up ribosomes (most
common);tRNA- carries amino acids; DNA- carries genetic code
6. Enzymes
a. Biological catalysts (made of protein) that speed up rate of chemical reactions by lowering
activation energy required for reaction to occur
b. Enzyme has active site (exposed R groups) where reaction occurs
c. Enzymes can break down substance (catabolic reaction) or build up substances (anabolic)
d. Enzyme/substrate complex is formed
e. Substrate is what enzyme acts on
f. Rate is determined by collisions between substrate and enzyme
g. Ends in –ase, named after substrate often
h. Enzyme is specific to substrate; the substrate must be complementary to the surface properties
(shape and charge) of the active site (which is made up of R groups with specific chemistry, i.e.
hydrophobic).
i. Enzyme rate is affected by:
• pH (optimal for each enzyme),
• temperature (optimal for each enzyme but in general increased temp means increased
collisions so rate goes up initially; too much heat can denature enzyme), enzyme
concentration (more enzyme faster rate or vice versa)
• substrate concentration (more substrate faster rate; vmax is fastest enzyme can work when
saturated)
j. Inhibition-competitive inhibition (something competes for active site; can be overcome with more
substrate)
k. Non-competitive inhibition- attaches at allosteric site and changes shape of enzyme so it is not
functional; can not be overcome with more substrate
l. Coenzymes (organic; NAD and vitamin B etc.) and cofactors (inorganic; zinc, magnesium etc.)
interact with enzymes to put them into the right structure to do work.
Vocabulary
active site denaturation non-polar molecule
allosteric site disaccharide nucleic acid
amino acid hydrogen bond nucleotide
amphipathic hydrophilic organic molecule
anabolic hydrophobic peptide bond
carbohydrate ion polar molecule
carbon lipid polymer
catabolic macromolecule protein
catalyst monomer substrate
coenzyme monosaccharide water
, Page 4 AP Biology: 2026 Exam Review
Thinking Practice
1. If the following molecules were to undergo a dehydration synthesis reaction, what molecules would
result? Circle the parts of each amino acid that will interact and draw the resulting molecule.
The OH from amino acid 1 and the H from amino acid two combine to form water in dehydration synthesis.
2. Construct a bar graph that displays the relative amounts of hydrogen, carbon, oxygen, and nitrogen in
each of the four types of macromolecules (carbohydrates, lipids, proteins, nucleic acids).
carbohydrates: hydrogen=2; oxygen=1; carbon=1; nitrogen=0
lipids: hydrogen=1; oxygen=1; carbon=1; nitrogen=0
proteins: hydrogen=2; oxygen=1; carbon=1; nitrogen=1
nucleic acids: hydrogen=1; oxygen=1; carbon=1; nitrogen=1
3. Describe the relationship between substrate concentration and reaction rate shown in the graph below and
propose an explanation for it.:
J curve/exponential growth until it reaches the maximum, then it levels off. The enzyme concentration is
constant and as more substrate is added the enzyme becomes saturated with substrate reaching a maximum
rate of reaction, leveling off.
