Given a scientific passage and an answer, generate a question for the given answer.

Passage: Saturated fatty acids have only single bonds between carbon atoms. As a result, the carbon atoms are bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogens. Saturated fatty acids are found in fats. Answer: saturated
Carbon atoms are bonded to as many hydrogen atoms as possible in what type of fatty acids?

Passage: Chemical reactions constantly occur inside the cells of living things. However, under the conditions inside cells, most biochemical reactions would occur too slowly to maintain life. That's where enzymes come in. Enzymes are catalysts in living things. Like other catalysts, they speed up chemical reactions. Enzymes are proteins that are synthesized in the cells that need them, based on instructions encoded in the cells' DNA. Answer: enzymes
What proteins synthesized in cells act as catalysts?

Passage: As shown in Figure below , transcription is controlled by regulatory proteins . The proteins bind to regions of DNA, called regulatory elements , which are located near promoters. After regulatory proteins bind to regulatory elements, they can interact with RNA polymerase, the enzyme that transcribes DNA to mRNA. Regulatory proteins are typically either activators or repressors. Answer: regulatory
Dna transcription is controlled by what type of proteins?