AP BIOLOGY EXAM 2021|Complete Questions with A+ Graded
Answers |Updated 2024\2025
Water characteristics
polar, cohesion (hold together), adhesion (hold to another substance), surface tension, specific heat,
heat of vaporization
Surface Tension
A measure of how difficult it is to stretch or break the surface of a liquid
Specific Heat
amount of heat absorbed or lost to change temperature by 1C
Heat of Vaporization
the quantity of heat required to convert 1 from liquid to gas
Water polarity
uneven sharing of electrons that produces a negative charge near the oxygen atom and positive
charges near each hydrogen atom
Water properties
solvent, cohesive, thermal
Organic Chemistry
the study of carbon compounds
Hydroxyl
OH-, alcohol/ethanol
Carbonyl
C=O, aldehyde, keytone
Carboxyl
O=C-OH, carboxylic acid as in acetic acid
Amino
H-N-H, amine as in tryptophan
Sulfhydryl
R-SH
four organic compounds
carbohydrates, lipids, proteins, nucleic acids
,Monosaccharides
glucose, fructose, galactose
Disaccharides
sucrose, lactose, maltose
Polysaccharides
glycogen, starch, cellulose
Glycogen
storage polysaccharide form of glucose in animals
Starch
storage polysaccharide form of glucose in plants
Cellulose
Carbohydrate component of plant cell walls.
Condensation v. Hydrolysis
Condensation: anabolic, water out
Hydrolysis: catabolic, water in
Protein (condensation/hydrolysis)
Amino acid ---> dipeptide ---> polypeptide
Carbohydrates (condensation/hydrolysis)
Monosaccharide ---> Disaccharide ---> Polysaccharide
Glycosidic bond
bond formed by a dehydration reaction between two monosaccharides (+ water in product)
2 families of nitrogenous bases
pyrimidines and purines
Complementary base pairing
A & T = 2 hydrogen bonds
C & G = 3 hydrogen bonds
DNA Structure
Phosphodiester: between phosphates & sugars
Covalent: between sugar & base pair
Hydrogen: between base pairs
Protein Structure
, amino group-r side chain-carboxyl group
Primary
amino acid sequence, peptide bonds
Secondary
representing local structure, held by H+ bonds
Tertiary
folding of a single protein
Quaternary
protein complex
Two forms of proteins
globular (insoluble, structural) and fibrous (soluble, functional)
Fibrous proteins
long, insoluble, structural proteins (keratin, elastin)
Globular proteins
chunk, soluble (amylase, insulin, hemoglobin, immunoglobin, transport pumps)
Anabolic reactions
build complex molecules from simpler ones, endergonic, biosynthetic (example: photosynthesis)
Catabolic reactions
breakdown of molecules, exergonic, degradative (example: cellular respiration)
First Law of Thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed.
Second Law of Thermodynamics
Every energy transfer makes the universe more disordered = increases entropy
Free energy
amount of energy available to do work...ΔG =ΔH−TΔS
ΔG (Gibbs)
change in free energy
ΔH (enthalpy)
change in total energy
Answers |Updated 2024\2025
Water characteristics
polar, cohesion (hold together), adhesion (hold to another substance), surface tension, specific heat,
heat of vaporization
Surface Tension
A measure of how difficult it is to stretch or break the surface of a liquid
Specific Heat
amount of heat absorbed or lost to change temperature by 1C
Heat of Vaporization
the quantity of heat required to convert 1 from liquid to gas
Water polarity
uneven sharing of electrons that produces a negative charge near the oxygen atom and positive
charges near each hydrogen atom
Water properties
solvent, cohesive, thermal
Organic Chemistry
the study of carbon compounds
Hydroxyl
OH-, alcohol/ethanol
Carbonyl
C=O, aldehyde, keytone
Carboxyl
O=C-OH, carboxylic acid as in acetic acid
Amino
H-N-H, amine as in tryptophan
Sulfhydryl
R-SH
four organic compounds
carbohydrates, lipids, proteins, nucleic acids
,Monosaccharides
glucose, fructose, galactose
Disaccharides
sucrose, lactose, maltose
Polysaccharides
glycogen, starch, cellulose
Glycogen
storage polysaccharide form of glucose in animals
Starch
storage polysaccharide form of glucose in plants
Cellulose
Carbohydrate component of plant cell walls.
Condensation v. Hydrolysis
Condensation: anabolic, water out
Hydrolysis: catabolic, water in
Protein (condensation/hydrolysis)
Amino acid ---> dipeptide ---> polypeptide
Carbohydrates (condensation/hydrolysis)
Monosaccharide ---> Disaccharide ---> Polysaccharide
Glycosidic bond
bond formed by a dehydration reaction between two monosaccharides (+ water in product)
2 families of nitrogenous bases
pyrimidines and purines
Complementary base pairing
A & T = 2 hydrogen bonds
C & G = 3 hydrogen bonds
DNA Structure
Phosphodiester: between phosphates & sugars
Covalent: between sugar & base pair
Hydrogen: between base pairs
Protein Structure
, amino group-r side chain-carboxyl group
Primary
amino acid sequence, peptide bonds
Secondary
representing local structure, held by H+ bonds
Tertiary
folding of a single protein
Quaternary
protein complex
Two forms of proteins
globular (insoluble, structural) and fibrous (soluble, functional)
Fibrous proteins
long, insoluble, structural proteins (keratin, elastin)
Globular proteins
chunk, soluble (amylase, insulin, hemoglobin, immunoglobin, transport pumps)
Anabolic reactions
build complex molecules from simpler ones, endergonic, biosynthetic (example: photosynthesis)
Catabolic reactions
breakdown of molecules, exergonic, degradative (example: cellular respiration)
First Law of Thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed.
Second Law of Thermodynamics
Every energy transfer makes the universe more disordered = increases entropy
Free energy
amount of energy available to do work...ΔG =ΔH−TΔS
ΔG (Gibbs)
change in free energy
ΔH (enthalpy)
change in total energy
