All living things are made up of four classes of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids. Macromolecules are large molecules composed of thousands of covalently connected atoms, also called polymers. A polymer is a long molecule consisting of many similar building blocks; the small building-block molecules are called monomers.

Question

All cells have thousands of different macromolecules, that vary among cells of an organism, vary more within a species, and vary even more between species. A huge variety of polymers can be built from a small set of monomers.

What statements are true about the biological macromolecules. (Choose 3)

Responses

All biomolecules could be called carbon-based molecules.
All biomolecules could be called carbon-based molecules.

The monomers of DNA are nucleotides.
The monomers of DNA are nucleotides.

Ready cellular energy comes in the form of lipids.
Ready cellular energy comes in the form of lipids.

Carbohydrates contain nitrogen and therefore differ from the other macromolecules
Carbohydrates contain nitrogen and therefore differ from the other macromolecules

Cell membranes are made, in part, from phospholipids.

Answer 1

The true statements about biological macromolecules are:

1. All biomolecules could be called carbon-based molecules.
2. The monomers of DNA are nucleotides.
3. Cell membranes are made, in part, from phospholipids.

The statement "Ready cellular energy comes in the form of lipids" is not accurate; while lipids can store energy, immediate energy is primarily derived from carbohydrates (like glucose). The statement "Carbohydrates contain nitrogen and therefore differ from the other macromolecules" is also false, as carbohydrates do not typically contain nitrogen in their structure.