Across 1. protein that acts as a catalyst in biochemical reactions 6. component of fat molecule 8. acidic group in amino acids 9. monosaccharide commonly found in fruit 11. fatty acid with hydrogens in different planes 12. monomer subunit of protein 14. major constituent of plasma membrane 17. fatty acid containing no double bonds 18. nucleic acid found only in RNA 19. bond formed between two amino acids 20. number of amino acids Down 2. single unit of a polymer 3. structure of polypeptide chain that contains beta sheets 4. provides structural support in plant cells 5. type of bond between monosaccharides in a chain 7. used for long term energy storage 10. biological macromolecule with a ratio of 1 C:2 H:1 O 13. sugar backbone of DNA 15. type of reaction used to form polymers 16. adenine and guanine are this type of nucleotide