Question

grace, mason, and aiden are in a science competition. they need to identify the substance that speeds up chemical reactions by lowering activation energy. what is the substance they are looking for?
nucleic acids
carbohydrates
proteins
lipids
the diagram shows the structure of starch, a complex carbohydrate. what best describes the relationship between starch and glucose?
starch is a polymer made of glucose monomers.
starch and glucose are reactants that combine to form proteins.
starch is a monomer that is used to make glucose.
starch and glucose are reactants that combine to form nucleic acids.

Explanation:

First Question:

To solve this, we recall the function of each substance:

• Nucleic acids store genetic info.
• Carbohydrates are energy sources.
• Proteins (enzymes are proteins) speed up reactions by lowering activation energy.
• Lipids are for energy storage/structure. So the substance is a protein.

Starch is a complex carbohydrate. A polymer is made of repeating monomers. Glucose is a monosaccharide (monomer), and starch is a polysaccharide (polymer) formed by linking glucose monomers. Other options are incorrect (starch/glucose don't form proteins/nucleic acids, starch is not a monomer for glucose).

Answer:

C. proteins

Second Question: