Question

which of the below are macromolecules of life? *
proteins
lipids
carbohydrates
all of these plus nucleic acids
which of the below is true of enzymes? *
they bind at the active site
they are specific to the substrate they work on
they decrease the activation energy needed for a reaction to occur, speeding the reaction
all of these

Explanation:

1. Proteins, lipids, carbohydrates, and nucleic acids are all macromolecules of life. Proteins have various functions like catalysis and structure - building, lipids are important for energy storage and membrane formation, carbohydrates are energy sources, and nucleic acids store genetic information.
2. Enzymes bind to substrates at the active site, are specific to the substrates they act on, and lower the activation energy of a reaction, thus speeding it up.

Answer:

1. all of these plus nucleic acids
2. all of these