How does an enzyme speed up a chemical reaction? enzymes:
a: lower the activation energy of chemical reactions.
b: raise the temperature of the cell, speeding chemical reactions.
c: store atp, allowing more energy to be used in chemical reactions.
d: act as a miniature “transfer trucks” gathering materials for chemical reactions and places them together.

What is the main difference between primary and secondary sources? a. primary sources are historical documents, and secondary sources are modern-day documents. b. primary sources are derived from museums and archives, and secondary sources are created by history students and academics. c. primary sources are found in ancient places with a rich history, and secondary sources are found in historical journals and blogs. d. primary sources are created during a particular historical era, and secondary sources are created by studying primary sources.