Which one of the following statements is true of enzyme catalysts? A) Their catalytic activity is independent of pH. B) They are generally equally active on D and L isomers of a given substrate. C) They can increase the equilibrium constant for a given reaction by a thousand-fold or more. D) They can increase the reaction rate for a given reaction by a thousand-fold or more. E) To be effective, they must be present at the same concentration as their substrate

D) They can increase the reaction rate for a given reaction by a thousand-fold or more.

Explanation:

Enzymes are like catalysts with the only difference that they are bio-molecules. Biochemical/chemical reactions are slow because of 'transition state barriers' which require a lot of energy to overcome so enzymes rather than overcoming transition state barrier provide an alternate pathway for biochemical reactions which require comparatively less energy. Thus presence of an enzyme leads to an increase in reaction rate because alternate pathway which requires less energy makes the rate of chemical reaction rapid by a thousand-fold or more.

correct answer: understand the different control methods available

integrated pest management is an strategy that is based on the ecosystem and try to prevent the pest and the damage caused by them by applying combination of technique like habitat manipulation, biological control and use of resistant varieties.

the main aim of the integrated pest management is not to completely eliminate the pest but to strengthen the ecosystem so that conditions are favorable for plants and unfavorable for pests.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!