Essentials of Biology: Photosynthesis and Cellular Respiration

Question #1 

Photosynthesis is a chemical reaction that transforms carbon dioxide (CO 2 ) and water (H 2 O) into glucose and oxygen using the energy from sunlight. Cellular respiration, on the other side, is the process of breaking down simple sugars into CO 2 and H 2 O to release energy in the form of adenosine triphosphate (ATP) (Robertson, Jennings, Honeycutt, Keith & Tai, 2016). 

Question #2 

The components that react during cell respiration are the by-products of photosynthesis and vice versa. Photosynthesis is a producer of glucose from CO 2 and H 2 O, while the cellular respiration is a consumer of glucose during the process of producing ATP. Oxygen and glucose, which are by-products of photosynthesis, are essential reactants during aerobic cellular respiration. On the other hand, CO 2 and H 2 O, which are the end products of cell respiration, are important components when it comes to photosynthesis. The two processes are interconnected through the carbon cycle, with one process consuming CO 2 and the other process releasing CO 2 into the atmosphere (Robertson et al., 2016). 

Question #3 

Body cells require oxygen for aerobic cellular respiration. If the supply of oxygen falls short, the cell will produce ATP anaerobically. Instead of going through the three cycles of cellular respiration, ATP is produced during the process of glycolysis. To acquire energy during glycolysis, NAD + ought to be there to accept electrons. This is not a problem during an aerobic respiration since there are acceptors in the form of oxygen to receive hydrogen for the regeneration of NAD + from NADH. Therefore, since NAD + cannot be recycled during anaerobic respiration, the body has to rely on the two ATP molecules produced when the simple sugar is converted into pyruvic acid. Due to the low 2 ATP molecules produced compared to 32 ATP molecules produced during aerobic cellular respiration, the body may suffer from the lack of energy. Also, the process of fermentation produces lactic acids, which can denature enzymes. Finally, when the brain experiences a shortage of ATP, it might die, leading to your death (Mader et al., 2007). 

Question #4 

According to the Alvarez hypothesis, a huge meteor fell from space, causing the accumulation of gas, dust, and debris in the earth’s atmosphere. The process of photosynthesis requires a specific wavelength of light from the sun to occur. The visible light, which is the best wavelength for the process of photosynthesis, could not penetrate the dense layer of dust and debris that filled up the atmosphere. Thus, plants could not produce food. Unlike plants, which are autotrophs, dinosaurs were heterotrophs. They could not produce their own food. This species was starved to death as a result of inadequate food production through the process of photosynthesis (Johnson, 2018). 

Question #5 

Chloroplast 

Chloroplasts are made of three major components: envelope, stroma, and thylakoids. The envelope bounds the entire chloroplast. The transfer of molecules between chloroplast and cytosol takes place through the envelope. Stroma is a gel-fluid phase that surrounds the thylakoids. It carries proteins, ribosomes, and the DNA of the chloroplast. It is the site of CO 2 fixation. The synthesis of sugar, fatty acids, starch, and some protein, occurs in the stroma. Finally, the thylakoids are flattened and closed vesicles organized into a membrane network. Light reaction takes place in the thylakoids membrane (Landowne, 2010). 

Mitochondria 

The major components of mitochondria include intermembrane space, inner membrane, matrix, outer membrane, and the cristae. The intermembrane space is small for quick and efficient accumulation of protons. The inner membrane possesses Electron Transport Chain (ETC) and ATP synthase for oxidative phosphorylation. The matrix hosts the Krebs cycle. The matrix has a suitable pH and required enzymes for the citric acid cycle. The outer membrane has transport proteins that contain pyruvate within the mitochondria. Finally, the Cristae is a highly folded membrane to increase the surface area to volume ratio for the process of cellular respiration (Landowne, 2010). 

References 

Mader, S. S., Windelspecht, M., & Preston, L. (2007).  Essentials of biology . McGraw-Hill higher education. 

Johnson, D. (2018). Conflicting Theories: Impact and Volcanism. 

Robertson, L., Jennings, L., Honeycutt, S., Keith, K., & Tai, C. C. (2016). Photosynthesis and Cellular Respiration (LS1): A Hands-On Approach for Grades 6–12. 

Landowne D. (2010). Cell Physiology . McGraw Hill Professional.