Sugars
What is the general chemical formula of monosaccharides?
(CH₂O)ₙ
Are lipids generally soluble or insoluble in water?
Insoluble
How many different amino acids are commonly found in proteins?
20
What are the three components of a nucleotide?
Base, sugar, phosphate
What type of reaction forms covalent bonds between biological monomers?
Condensation
What type of bond links two monosaccharides together during disaccharide formation?
Glycosidic bond
What type of linkage connects fatty acids to glycerol in triacylglycerols?
Ester linkage
Which two functional groups are present in all amino acids?
Amino group & carboxyl group
What type of bond connects nucleotides together in DNA and RNA?
Phosphodiester linkage
What reaction breaks polymers back into monomers?
Hydrolysis
Glucose is most commonly found as what type of sugar based on carbon number?
Hexose
What term describes fatty acids that contain both hydrophilic and hydrophobic regions?
Amphipathic
What type of bond links amino acids together in a protein?
Peptide bond
Which base pairs are held together by three hydrogen bonds?
G–C
What molecule is released during condensation reactions?
Water
What structural difference explains why cellulose cannot be digested by humans but starch can?
α vs β glycosidic linkages
How does the presence of double bonds affect the physical properties of fatty acids?
Double bonds cause bending and increase fluidity
How do amino acid side chains (R-groups) influence protein structure and function?
R-groups determine charge, polarity, and interactions
What gives nucleic acids their structural polarity?
5′ phosphate and 3′ hydroxyl ends
Why are covalent bonds critical for forming biological macromolecules?
They provide stable molecular backbones
Cellulose and starch are both polymers of glucose. What specific feature of their glycosidic linkages makes cellulose a structural polysaccharide?
β-glycosidic linkages create straight, rigid chains
Explain how phospholipid structure makes them ideal for forming biological membranes.
Hydrophilic heads + hydrophobic tails form bilayers
Why does cysteine play a unique role in protein structure compared to other nonpolar amino acids?
Cysteine forms disulfide bonds
How does complementary base pairing contribute to DNA replication fidelity?
Ensures accurate complementary strand synthesis
During protein assembly and folding, different types of chemical bonds are responsible for different levels of structure.
Identify the types of bonds involved in forming the primary structure of a protein and the bonds/interactions that stabilize higher levels of protein structure.
Primary structure:
Formed by covalent peptide bonds linking amino acids together.
Secondary, tertiary, and quaternary structures:
Stabilized by noncovalent interactions, including:
Hydrogen bonds
Ionic (electrostatic) interactions
Hydrophobic interactions
van der Waals attractions
Disulfide bonds (covalent, between cysteine side chains)