An allergic reaction to certain types of natural,
unprocessed foods, such as peanuts, is caused by
(1) a lack of digestive enzymes
(2) a response to specific antigens
(3) microorganisms living within the food
(4) high levels of carbon dioxide in the air

Aseries of connections of food chain in an ecosystem is called a what

1. environmental factors, such as ph and temperature, can affect the function of an enzyme. a. true b. false 2. which of the following is an organic molecules (ex. vitamins) that an enzyme? a. coenzyme b. product c. active site d. substrate 3. how do enzymes effect the speed of a chemical reaction? a. they speed it up b. they slow it down c. they have no effect on the speed of a reaction 4. during a chemical reaction, an enzyme is used up so that it can only be used one time. a. true b. false 5. which of the following results from a chemical reaction that is catalyzed by an enzymes? a. active site b. product c. substrate d. coenzyme

When analyzing tree rings, what do scientists assume a thin ring indicates?