The enzyme polyphenol oxidase and the substrate polyphenol can be extracted from crushed apples. The substrate turns brown when the enzyme is present. Some students were provided with extracts of the enzyme and the substrate. Describe a method the students could use to find the optimum temperature of the enzyme.

Sydney drew a flow chart to illustrate the nitrogen cycle.which labels best complete the flow chart? x: producers undergo photosynthesis.y: nitrogen compounds are released into the air.x: nitrogen compounds are released into the air.y: producers undergo photosynthesis.x: free nitrogen is in the atmosphere.y: producers absorb nitrogen compounds through their roots.x: producers absorb nitrogen compounds through their roots.y: free nitrogen is in the atmosphere.

What kind of crystalline solid is graphite? o a. molecular solid b. metallic solid o c. network solid d. ionic solid

Cassandra made a venn diagram to compare and contrast the two stages of cellular respiration. which belongs in the area marked x? energy is released. oxygen is used up. glucose is broken down. carbon dioxide is used up.