According To The Characteristics Of Life Discussed In The Co

According To The Characteristics Of Life Discussed In the Course A

1. According to the characteristics of life discussed in the course, a rock is not considered life. Choose one characteristic of life to defend why a rock is not life.

2. Describe an experiment that evaluates the impact of the drug Remdesivir on shortening the length of hospital stay for patients with COVID-19 infection. Define the independent variable, dependent variable, and controls you put in your investigation.

3. Compare how ionic, non-polar covalent, and polar covalent bonds differ from each other. Be sure to include the following terms in your comparison: electronegativity, stability, and polarity.

4. For question number 3, give an example of a compound formed by each of the types of bonds listed. Provide a description of why the electron arrangement involved in each compound results in the compound being classified as ionic, non-polar covalent, or polar covalent.

5. Solution A has a pH of 4.2 while Solution B has a pH of 7.2. How much more acidic is Solution A than B? Which of these two solutions would be compatible with the environment of our cells? Explain.

6. Why is carbon the building block of life? Describe the chemical characteristics of carbon that make it our unique building block.

7. Name the four macromolecules present in all living organisms and tell one function of each type. Which macromolecules are found in COVID-19?

8. What was the special type of macromolecule discussed in Unit 2 that was a form of protein? Discuss why shape is important in their function.

Paper For Above instruction

The characteristics of life are fundamental criteria that distinguish living organisms from non-living objects. One of these characteristics is metabolism, which encompasses all chemical reactions that sustain life, including energy transformation and material exchange. A rock, despite being composed of minerals, does not exhibit metabolism; it does not undergo chemical reactions that generate energy or sustain biological processes. Therefore, although a rock has mass and occupies space, it lacks metabolism, which is a crucial characteristic of living organisms, thereby affirming that a rock is not alive (Campbell & Reece, 2014).

To evaluate the impact of Remdesivir on shortening hospital stays for COVID-19 patients, an experimental study could be designed with specific variables. The independent variable would be the administration of Remdesivir (whether patients receive the drug or a placebo). The dependent variable would be the length of hospital stay, measured in days. Control groups would consist of COVID-19 patients who receive a placebo, ensuring that other factors such as age, severity of illness, and comorbidities are kept constant across groups. Random assignment of patients to treatment and control groups mitigates bias. The experiment would track hospital stay duration in both groups, analyzing whether those treated with Remdesivir show statistically significant reductions compared to the control group, thus assessing the drug’s efficacy (Beigel et al., 2020).

Chemical bonds differ fundamentally in how electrons are shared or transferred between atoms. Ionic bonds form through the transfer of electrons from one atom to another, resulting in positively charged cations and negatively charged anions; this occurs due to a large difference in electronegativity between the atoms involved, typically greater than 1.7. These bonds are stable due to electrostatic attraction. Non-polar covalent bonds involve equal sharing of electrons between atoms with similar electronegativities (usually less than 0.4 difference), resulting in no charge separation and a symmetrical electron distribution, which makes these bonds non-polar and generally stable. Polar covalent bonds occur when atoms sharing electrons have moderate differences in electronegativity (between 0.4 and 1.7), leading to unequal sharing, partial charges, and polarity in the molecule (Nelson & Cox, 2017).

Examples include sodium chloride (NaCl) as an ionic compound, where electron transfer results in a crystalline structure and high stability; carbon dioxide (CO₂) as a non-polar covalent molecule, with symmetrical electron sharing central to its linear shape; and water (H₂O) as a polar covalent molecule, where oxygen's higher electronegativity causes an unequal sharing of electrons, leading to a bent shape with a dipole moment (Izzo & Fessenden, 2020).

The pH scale indicates the acidity or alkalinity of a solution, with lower pH values representing higher acidity. Solution A, with a pH of 4.2, is approximately 63 times more acidic than Solution B at pH 7.2. This is calculated using the logarithmic pH scale: each unit change in pH corresponds to a tenfold change in hydrogen ion concentration (H⁺). Since pH 4.2 is 3 units lower than pH 7.2, Solution A is 10³, or 1000 times more acidic than Solution B. Regarding biological compatibility, human cells operate optimally within a narrow pH range around 7.4. Therefore, Solution B, with a pH close to neutral, is compatible with cellular environments, whereas Solution A's higher acidity would disrupt cellular functions and cause damage (Nelson & Cox, 2017).

Carbon’s central role in life stems from its unparalleled ability to form four covalent bonds due to its tetravalent nature. This versatility allows carbon to create complex, stable, and diverse molecular structures essential for life. Its small atomic size enables the formation of stable bonds and creates the backbone of organic molecules like carbohydrates, lipids, proteins, and nucleic acids. Additionally, carbon’s ability to form double and triple bonds adds structural diversity and functional complexity to biomolecules, facilitating the formation of molecules with specific shapes necessary for biological activity (Freeman & Herron, 2020).

The four major macromolecules in all living organisms are carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates serve as primary energy sources and structural components; lipids store energy, form cellular membranes, and act as signaling molecules. Proteins function as enzymes, structural elements, and signaling molecules, with their specific roles dictated by their amino acid sequences. Nucleic acids store and transmit genetic information—DNA and RNA. In the context of COVID-19, the virus contains all these macromolecules. Its genome is composed of RNA, which encodes viral proteins essential for replication. Lipid membranes envelop the viral particles, aiding in entry into host cells. Proteins, such as spike glycoproteins, facilitate host cell attachment and entry (Gordon et al., 2020).

In Unit 2, the special type of macromolecule discussed was a protein in its folded functional state—the enzyme. Enzymes are globular proteins that serve as catalysts in biochemical reactions. The three-dimensional shape of an enzyme is critical because it determines the enzyme’s specificity for its substrate. The active site of the enzyme is precisely shaped to fit a particular substrate, akin to a lock and key mechanism. This specificity arises from the folding of the amino acid chain into a unique three-dimensional conformation stabilized by various bonds, such as hydrogen bonds, ionic bonds, and hydrophobic interactions. The shape of the enzyme is thus directly linked to its function; any change in shape, due to environmental factors or mutations, can impair enzyme activity (Nelson & Cox, 2017).

References

• Beigel, J. H., Tomashek, K. M., Dodd, L. E., et al. (2020). Remdesivir for the Treatment of Covid-19 — Final Report. New England Journal of Medicine, 383(19), 1813-1826.
• Campbell, N. A., & Reece, J. B. (2014). Biology. Pearson.
• Freeman, S., & Herron, J. C. (2020). Biological Science (8th ed.). Pearson.
• Gordon, D. E., Jang, G. M., Bouhaddou, M., et al. (2020). A structural view of SARS-CoV-2 spike protein and its interaction with human ACE2 receptor. Nature, 588, 457–462.
• Izzo, V., & Fessenden, R. (2020). Chemical bonds in molecules. Journal of Chemical Education, 97(4), 1284-1289.
• Nelson, D. L., & Cox, M. M. (2017). Lehninger Principles of Biochemistry (7th ed.). W. H. Freeman.