Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 2

Photosynthetic Energy Transduction. The amount of energy trapped and the volume of carbon converted to organic form by photosynthetic energy transducers are mind-boggling: about 5 × 10 16 g of carbon per year over the entire Earths surface.
(a)Assuming that the average organic molecule in a cell has about the same proportion of carbon as glucose does, how many grams of organic matter are produced annually by carbon-fixing phototrophs
(b)Assuming that all the organic matter in part a is glucose (or any molecule with an energy content equivalent to that of glucose), how much energy is represented by that quantity of organic matter Assume that glucose has a free energy content (free energy of combustion)of 3.8 kcal/g.
(c)Referring to the answer for Problem 5-la, what is the average efficiency with which the radiant energy incident on the upper atmosphere is trapped photosynthetically on the Earths surface
(d)What proportion of the net annual phototrophic production of organic matter calculated in part a do you think is consumed by chemotrophs each year