Question

monosaccharides : carbohydratesamino acids : secondary structure of the polypeptide
nucleotides : dna
fatty acids, glycerol : triglycerides
phosphate, sugar : nucleotide
4 carbon rings : steroids
glycerol, three fatty acids : phospholipids

Explanation:

1. monosaccharides : carbohydrates: Monosaccharides are the monomer building blocks of carbohydrates (polysaccharides), so this pair is correct.
2. amino acids : secondary structure of the polypeptide: Amino acids are the monomers that form polypeptides, but the secondary structure refers to folding patterns (alpha-helices, beta-sheets) of the polypeptide chain, not the direct monomer-polymer relationship. This pair is incorrect.
3. nucleotides : DNA: Nucleotides are the monomer building blocks of DNA (a nucleic acid polymer), so this pair is correct.
4. fatty acids, glycerol : triglycerides: Triglycerides are formed by bonding one glycerol molecule with three fatty acids, so this monomer-polymer pair is correct.
5. phosphate, sugar : nucleotide: A nucleotide is composed of a phosphate group, a sugar, and a nitrogenous base. This pair is missing a key component, so it is incorrect.
6. 4 carbon rings : steroids: Steroids are a class of lipids defined by their core structure of four fused carbon rings, so this pair is correct.
7. glycerol, three fatty acids : phospholipids: Phospholipids consist of a glycerol, two fatty acids, and a phosphate group (not three fatty acids). This pair is incorrect.

Answer:

• ✅ monosaccharides : carbohydrates
• ❌ amino acids : secondary structure of the polypeptide
• ✅ nucleotides : DNA
• ✅ fatty acids, glycerol : triglycerides
• ❌ phosphate, sugar : nucleotide
• ✅ 4 carbon rings : steroids
• ❌ glycerol, three fatty acids : phospholipids