Which part of the respiratory system does the transition from bulk flow of air to diffusion of individual gases occur?

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

Where would you expect to see seedless plants, such as ferns and mosses? a. in a botanical museum, because they are all extinct b. low and close to the ground in a moist environment c. climbing high while circling the branches of another plant d. deeply rooted in a forest with a trunk that reaches 20 meters or more

Describe the response the kidneys have to dehydration and excessive water intake. what happens to the concentration of urine in each case ?