Hundredfold serial dilutions were prepared using 5 blanks. A one ml aliquot wasplated out of the first four dilution blanks. Both a 1 ml and a 0.1 ml aliquot were platedout of the final blank. The plates were then incubated for 48 hours at 35°C. Thecounts of the plates were asfollows:

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.