1. Organisms that use photosynthesis to produce glucose are collectively called photoautotrophs; three specific examples of such organisms are Rhodospirillum rubrum, Chromatium okenii, and Chlorobium limicola (Sengbusch, 2003). 2. Obligate aerobes are organisms that exclusively utilize aerobic cellular respiration; examples of such organisms are Bacillus, Pseudomonas, and Nocardia (Schlegel, 2003).
3. Unlike in aerobic cellular fermentation, organisms that utilize fermentation in cases wherein oxygen is absent use pyruvate along with other compounds derived from acetyl-CoA as a replacement for oxygen as the electron acceptor; examples of organisms which utilize fermentation are Streptococcus, Leuconostoc, and Pediococcus (Schlegel, 2003). 4.
Specificity and regulation are two of the most significant characteristics of enzymes in relation to catalyzing reactions; specificity pertains to the capability of enzymes to properly bind specific substrates, hence making the overall process efficient. Regulation, on the other hand, explains as to why inappropriate amounts of products produced are rare during normal conditions as the general trend is to reach equilibrium (Schlegel, 2003). References Cooper, J. P. (1975). Photosynthesis and Productivity in Different Environments.
Cambridge, UK: Cambridge University Press. Decelles, P. (2002, April 25). Cellular Respiration Overview. The Entangled Bank – Johnson Community College. Retrieved June 17, 2009, from http://staff. jccc. net/PDECELL/cellresp/respintro. html. Schlegel, H. G. (2003). General Microbiology. New York, NY: Cambridge University Press. Sengbusch, P. V. (2003, July 31). Photoautotrophic Bacteria. Botany Online – Evolution. Retrieved June 17, 2009, from http://www. biologie. uni-hamburg. de/b-online/e42/t3. htm .