Articles and Podcasts

By: Adrian Gore ● June 25th, 2022

How do you think we know so much about our past, some of it dating back to before the human race had a proper language and a way to record events? While we do rely on written works for more recent events, like World War 2 for example, much of what we know of society from before language and writing was invented stems from archaeology. Archaeology is the study of human history (and prehistory, meaning our human-like ancestors) through the excavation of sites and the analysis of artifacts and other physical remains. Archaeologists classify sites as prehistoric, or historic; with the difference being historic sites can have writing to use as reference and aid, while prehistoric sites cannot. Archaeologists often use what's known as the "direct historical approach" when examining artifacts and sites, where they compare the historical sites/artifacts with current cultures' artifacts (which are located in the same area). This allows them to effectively explain how and why certain cultures changed and adapted the way they did. Recent headlines in the field include the discovery of a 500 year old tomb in Peru (archaeology.org, June 24th), where archaeologists determined that the tomb likely belonged to members of the Ruricancho Society, a society that existed in Peru before the Incas. This was determined through observed differences in the cloth and ornaments within the tomb when compared to other societies that inhabited the area at different times. Simple observed differences like this give us more insight into the cultures and practices of those who came before us, and is important for us to determine patterns within the rise and fall of civilizations.

By: Adrian Gore ● April 17th, 2022

Anthropology is the study of humanity, focused on where we originated from, our diversity, and how our shared similarities and differences impact our interactions in the world. Anthropology has 3 main categories: sociocultural anthropology, biological anthropology, and archaeology. Sociocultural anthropology examines how a shared culture between people affects how they interact with each other within society. Sociocultural anthropologists focus on topics including gender relations, colonialism, family systems, and class structures. In contrast, biological anthropology studies human evolutionary biology and how adaptations affect human-environment interactions. A key area of study for biological anthropologists is the behavior of closely-related primates and humans, and the identification of similarities and differences in behavior to understand our behavioral roots. Finally, archaeology focuses on “material remains” of cultural systems, which helps better understand cultural evolutionary processes that form them. Recently, a study conducted by researchers at the Radboud University Medical Center found that “After the Neolithic, European populations showed an increase in height and intelligence, reduced skin pigmentation and increased risk of cardiovascular disease due to genetic changes that lowered concentrations of 'good' HDL cholesterol. The changes reflect ongoing evolutionary processes in humans and highlight the impact the Neolithic revolution had on our lifestyle and health.” This study clearly encapsulates the many aspects of anthropology, as biological diversity in the Neolithic period was studied (biological anthropology), the resulting eating habits and behaviors were observed (cultural), and the structural changes in societies as their lifestyle change was also noted (archaeology).

By: Varun Ajith ● November 2nd, 2021

Back in elementary and middle school, us kids were taught that the mitochondria was the “powerhouse” of the cell. I, as a former AP Biology student, now know that “powerhouse” was an oversimplified understatement of the mitochondria’s real job as part of the cell.

The main function of the mitochondria is to perform cellular respiration, a process that oxidizes glucose, lipids, and other macromolecules into energy and other products depending on your starting reactant (ex. With glucose, you end up producing carbon dioxide, water, and energy). The energy produced in cellular respiration is in the form of ATP, or adenosine triphosphate. It is an excellent energy donor, because the bonds between the phosphates are highly unstable, and are high in energy. But how do we generate this ATP? Through a process called cellular respiration (if you could have guessed by now). In this article, I will be talking about glucose as the starting product. Cellular respiration consists of 3 steps: glycolysis, the Krebs (Citric Acid) cycle, and oxidative phosphorylation.

Let’s talk about the first step: glycolysis. Glycolysis occurs in the cytoplasm of the cell outside the mitochondria. During glycolysis, glucose (6 carbon sugars) is oxidized to form 2 pyruvate molecules (3 carbon sugars) and water. It consists of 2 phases: the energy investment phase, and the energy payoff phase. During the energy investment phase, you actually end up using 2 ATP to jump start the process, which ends in glyceraldehyde 3-phosphate (G3P) being produced. During the energy payoff phase, G3P is oxidized, and the electrons are transferred to NAD+, an electron carrier, which is then reduced to NADH. The other occurrence is the production of 4 ATP molecules through substrate level phosphorylation, the direct transfer of a phosphate group from an organic substrate to ADP through an enzyme. One other important detail is that glycolysis is actually made up of 10 steps, with 10 different specific enzymes catalyzing each step. In all, 2 pyruvate molecules, 2 water molecules, 2 NADH, and 2 ATP are produced at the end of glycolysis (4 ATP - 2 ATP from energy investment). One final thing to know about glycolysis is that it doesn’t need aerobic conditions in order to be performed, which is a key determinant of supporting the theory of evolution. This is impactful because not all life can perform aerobic respiration, not all life have mitochondria, and the fact that glycolysis occurs in the cytosol means that all life uses glycolysis as a way to generate energy for the cell.

Now onto the next step of cellular respiration- the Krebs cycle. Now before we get into the Krebs cycle, some events take place between it and glycolysis. The 2 pyruvate molecules enter the mitochondria via active transport, and then get oxidized into acetyl CoA (formed with coenzyme A). This process is known as pyruvate oxidation, which is considered an intermediate between glycolysis and Krebs cycle. From this process, each pyruvate produces a carbon dioxide molecule, 1 NADH, and 1 acetyl CoA. Now onto the Krebs cycle. Firstly, it occurs in the mitochondrial matrix. The Krebs cycle ultimately converts acetyl CoA into 6 NADH, 2 FADH₂ , and 2 ATP per glucose molecule, and half those amounts per each acetyl CoA. The Krebs cycle and oxidative phosphorylation are both forms of aerobic respiration, so oxygen must be present during the 8 step reaction that makes up the Krebs cycle. Krebs cycle also is the way to recycle NAD+ for use in glycolysis. There are 2 ways in which NAD+ can be regenerated- with or without oxygen. NAD+ is recycled during pyruvate oxidation, which is aerobic respiration. However, if not in the presence of oxygen, you can use a process called fermentation to recycle NAD+. There are 2 forms of fermentation: alcoholic and lactic acid. In alcoholic fermentation, pyruvate is oxidized into ethanol and carbon dioxide, which allows for NADH to oxidize into NAD+ while in lactic acid fermentation, pyruvate is oxidized into lactic acid, which ultimately yields NAD+ regeneration as well. Now finally onto oxidative phosphorylation. Oxidative phosphorylation consists of 2 parts: the electron transport chain (ETC) and chemiosmosis. In the ETC, the various electron carriers, including NADH and FADH₂ deposits electrons that move through integral proteins in the inner mitochondrial membrane, from one protein to the next based on the electronegativity. The final electron acceptor in this chain is oxygen, which gets reduced to make water. Since electrons can’t be transported by themselves, they are transported as part of a hydrogen atom. When the electron is removed from electron carriers and moved through the ETC, protons are pumped from inside the matrix to the inter-membrane space of the mitochondria, which results in a proton gradient formation. The 2nd half of oxidative phosphorylation is chemiosmosis. The protons in the inter-membrane space are pumped back into the matrix via passive transport, and ATP is generated due the voltage that was generated. All in all, this process entirely produces about 26-28 ATP. That concludes cellular respiration. In all, you produce around 30-32 ATP through cellular respiration, which is used throughout the cell for the various processes of life.