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  • How Are Proteins Made?

    Written in March 2024 by Kaylyn Kim. This easy-to-understand study guide strives to give a brief overview of how proteins are produced. OVERVIEW OF PROCESS mRNA (messenger RNA) is produced. The mRNA strand leaves the nucleus and heads for the ribosome/cytoplasm area. The tRNA strands (connected to amino acids) match with the mRNA strand. A long amino-acid chain is produced. Proteins can be formed with these amino-acid chains (AKA polypeptides). KEY TERMS Enzyme: a kind of protein that expedites chemical processes Most enzymes end with the phrase "ase" Example) RNA polymerase, DNA polymerase DNA: deoxyribonucleic acid The genetic information that most of our cells contain in the nucleus Double-helix structure Gene: segments of the DNA that produce a specific protein and, in turn, determine a specific trait Allele: different kinds of genes Example) One gene can code for hair color (broader term), but one allele would code for brown hair (more specific). RNA: ribonucleic acid Typically single-stranded Different kinds) mRNA, tRNA, etc. Protein synthesis: the process in which proteins are produced Central Dogma: a term referring to how information goes from transcription (DNA --> RNA) to translation (RNA --> Amino Acids) Protein: molecules that help organisms survive Amino Acids: the material that the protein is made up of There are 9 essential amino acids that humans need to survive. Promoter: the marker that indicates where the RNA polymerase should attach to the DNA strand Terminator: the marker that indicates where the RNA polymerase should detach from the DNA strand Codons: a system for counting the nucleotide sequences in groups of 3 (triplets) Nucleotide: the material in which nucleic strands are made up of (both DNA and RNA have) DNA: Contains 1 nitrogenous base, 1 deoxyribose sugar, and 1 phosphate RNA: same as DNA, except that it contains a ribose sugar, instead of a deoxyribose one Ribosome: an organelle where protein synthesis takes place Made up of rRNA (ribosomal RNA) Has three sites for the tRNAs to briefly stay and pass on the amino acids Sites A, P, E --> The tRNAs rotate their locations in that respective order FIRST STEP: Transcription Location: nucleus DNA is unzipped by the RNA polymerase at the promoter. The RNA polymerase "reads" the DNA's bases and creates complementary pairs. Typically, adenine goes with thymine, but this time, thymine is replaced with a base pair called uracil. Guanine goes with cytosine (and vice versa) This forms an mRNA (messenger RNA) strand. It is then edited and sent out of the nucleus and into the cytoplasm. SECOND STEP: Translation Location: Cytoplasm/Ribosome The cytoplasm consists of tRNA (transfer RNA) strands that each have an amino acid attached to it. The tRNA strands "read" the mRNA's bases in threes (codons) and bind to the mRNA if they are complementary. EXTRA INFO: Each tRNA strand is called an "anticodon". Translation first starts at the start codon. While the tRNA strand leaves to find another matching codon, the tRNA will leave the amino acids behind, gradually making a long chain of amino acids. This continues until the stop codon indicates that the polypeptide (chain of amino acids) is complete. [NOTE: The following explanation is extremely simplified.] The final step differs for every kind of protein, but it typically requires multiple polypeptides to bond and fold into the shape of a specific kind of protein. Here are the sources I used to make this study guide. Feel free to look at these resources for more information! https://youtu.be/oefAI2x2CQM?feature=shared https://medlineplus.gov/ency/article/002222.htm https://my.clevelandclinic.org/health/articles/21532-enzymes https://www.khanacademy.org/science/ap-biology/heredity/mendelian-genetics-ap/v/alleles-and-genes#:~:text=Genes%20and%20alleles%2C%20two%20fundamental,traits%20such%20as%20eye%20color. https://www.khanacademy.org/science/biology/gene-expression-central-dogma/translation-polypeptides/a/trna-and-ribosomes https://www.genome.gov/genetics-glossary/Nucleotide https://medlineplus.gov/genetics/understanding/howgeneswork/protein/ https://www.cancer.gov/publications/dictionaries/genetics-dictionary/def/nucleotide https://youtu.be/hok2hyED9go?feature=shared Image Credits: https://stock.adobe.com/kr/search?k=dna+transcription https://studymind.co.uk/notes/transfer-rna/

  • Stem Cells on Genetic Engineering

    Written in March 2024 by Kaylyn Kim. This excerpt attempts to inform readers on how stem cells are being used to advance genetic engineering, along with addressing some of the current controversies regarding this research. Stem cells are uncategorized cells that can infinitely divide themselves and have the potential to become other kinds of cells. They can be found in the brain, bone marrow, skeletal muscles, and embryo. Mentioning embryos, there are two main types of stem cells. The first is embryonic stem cells. They are created through a process called in vitro fertilization, which, to give you a brief overview, is a process that involves using the totipotent stem cells from an embryo for surgical purposes. Totipotent means that they have total potential to become any other kind of cell. Meanwhile, the other predominant cell type is adult stem cells; these are the ones that our body uses when you get your arm burnt and need extra skin cells to replace the damaged ones. As mentioned previously, in vitro fertilization is the process of creating embryos in the laboratory. To walk you through the process, the sperm fertilizes the egg, and this forms a single, synthesis cell known as the zygote, shown in the image below. Through mitosis, this zygote divides until it forms a blastocyst, which is a cluster of 150-200 cells. In the blastocyst, there is the inner cell mass consisting of totipotent stem cells. These can be taken out through electricity or chemicals. Similar to vitro-fertilization, therapeutic cloning is another way of using embryonic stem cells. It involves taking an egg from a donor and a skin cell from a patient. Then, the doctor/surgeon/scientist can remove the DNA of the egg and replace it with the DNA of the patient’s skin cells. Through chemicals, the embryo dies, but the stem cells survive, which is then inserted into the patient. Earnest McCulloch and James Till were the true pioneers of stem cell research. In the 1960s, they discovered how hematopoietic (blood-making) stem cells were able to convert into any other kind of blood cell. But President Bush, through the Stem Cell Enhancement Act of 2005, banned the funding of cell research by the government. In 2009, this ban was lifted by President Obama. But why did these scientists want to learn more about stem cell therapy? First, stem cell therapy can treat cardiovascular and blood-related diseases by replacing the cells damaged by the disease with new stem cells. One day, this might also help regenerate organs, which is critical since there are not a lot of organ transplants readily available in proportion to those who are sick. Yet, there are many ethical implications to doing this. First, both vitro-fertilization and therapeutic cloning involve destroying a human blastocyst. So, research and development institutions face the difficult question, “When does life begin?” If, according to religion, life begins from conception, then using embryonic stem cells is essentially murder. But is it okay because these embryos are made in the laboratory and are not inserted into a woman’s body? Some pro-lifers support this since they believe conception is also relative to where development occurs. Hence, at the end of the day, religion and politics play a strong influence in answering this question. This is why institutions must provide informed consent and any information about the donors must be kept strictly confidential. To conclude, how does stem cell therapy change our world? First, there is a correlation between aging and the number of stem cells in the body, so this can potentially lead to cures to delay aging. Second, there might no longer be a need for organ donors anymore. But ultimately, stem cell research will influence our generation and those who come after us. It can provide treatments for the diseases that 100 million Americans currently have. So, today, I invite you to look briefly into stem cell research. After all, it could impact you, your family, or your future children one day. Works Cited Brazier, Yvette. “Stem Cells: Sources, Types, and Uses.” MedicalaNewsToday, 19 Oct. 2018, www.medicalnewstoday.com/articles/323343#donating-and-harvesting. Accessed 23 Mar. 2024. Harvard University. “Stem Cells: A Brief History and Outlook.” Science in the News, 3 Jan. 2014, sitn.hms.harvard.edu/flash/2014/stem-cells-a-brief-history-and-outlook-2/. Accessed 23 Mar. 2024. Lo, Bernard, and Lindsay Parham. “Ethical Issues in Stem Cell Research.” Endocrine Reviews, vol. 30, no. 3, 14 Apr. 2009, pp. 204–213, www.ncbi.nlm.nih.gov/pmc/articles/PMC2726839/, https://doi.org/10.1210/er.2008-0031. Accessed 23 Mar. 2024. Moradi, Mike. “Why Stem Cells Could Be the Medical Innovation of the Century.” World Economic Forum, 16 Jan. 2020, www.weforum.org/agenda/2020/01/how-will-stem-cells-impact-the-future-of-medicine/. Accessed 23 Mar. 2024. White, Deborah. “Arguments for and against Embryonic Stem Cell Research.” ThoughtCo, 24 May 2019, www.thoughtco.com/pros-cons-of-embryonic-stem-cell-research-3325609. Accessed 23 Mar. 2024. Image Citation Dahal, Prashant. “Zygote- Definition, Examples, Formation, Development, Challenges.” Microbe Notes, 3 Aug. 2023, microbenotes.com/zygote/. Accessed 23 Mar. 2024.

  • The Affect of Peer Influence on Adolescents

    Written in January 2024 by Kaylyn Kim This essay strives to answer the question, "How and Why Does Peer Influence Affect Adolescents?" Peer influence “…involves changing one’s behavior to meet the perceived expectations of others”. This phenomenon primarily affects adolescents—“the age between puberty…and the age at which you [they] attain a stable, independent role in society”—because of structural metamorphoses in the brain. Understanding why peer influence occurs and analyzing its effect on adolescents can help juvenile facilities create environments where adolescents can learn from their mistakes and grow. Recently, the University of Chicago Press conducted a study where adolescents were randomly assigned into peer groups to study together for an exam. The organization initially measured a student’s work ethic by four categories: how determined they were in the face of challenges, how confident they were of their academic skills, how anxious they were about their future success, and how prone they were to “engage in risky behavior”. Results of the experiment showed how studying with more persistent peers raised one’s overall GPA, whereas studying with risk-prone students had the opposite effect. Yet, the extent of peer influence lies far beyond how adolescents perform at school. To elaborate, Dr. Laurence Steinberg from Temple University created the “Spotlight Game”—an online game where an adolescent within a Magnetic Resonance Imaging (MRI) scanner must decide to stop or go at a yellow-light intersection. The first time, the participant plays, assuming no one is watching them. The second time, however, the adolescent hears their friends’ voices through a speaker and is notified that their friends are observing them. Adolescents had more car accidents in the virtual game when informed of their peers' presence. To explain this phenomenon, Sarah-Jayne Blakemore, a Psychology and Cognitive Neuroscience professor at the University of Cambridge, studied how the social brain—“the network of brain regions that are involved in understanding other people”—undergoes a rapid transformation during adolescence. First, the limbic system—the brain region that triggers human reward systems—is sensitive in adolescents because there is an increase in chemicals that heighten pleasure from risk-taking. In other words, adolescent brains directly view social acceptance from their peers as a reward for their risky behavior. Furthermore, the prefrontal cortex—the brain region that affects “… judgment, impulse control, and planning”—develops much later than the limbic system, explaining why adolescents rely more on emotions than reasoning. Consequently, this raises the dilemma of how adolescents should be punished for crimes. In the United States, two-thirds of juvenile facilities are correctional-style, meaning that adolescent criminals are confined from society when they commit a crime. Yet, since adolescent behavior changes with different peer influences, Michael Corriero—the founder of the New York Center for Juvenile Justice—advises that the primary goal when addressing juvenile crimes “…should be that of rehabilitation and not a punitive one”. As explored in this essay, peers have an increasing presence in one’s habits and decision-making skills during adolescence because of their developing limbic system and prefrontal cortex. While there is still debate on how to address juvenile crimes, examining the effect of peer influence on adolescents can eventually design a world that leads adolescents one step closer to adulthood. Bibliography Brains on Trial with Alan Alda: Peer Influence and Adolescent Behavior [online video], Brains on Trial, 26 September 2013, https://youtu.be/rt9MyNo65eI?si=th1Wu_0vsn8aEG9h, (Last Accessed: 30 December 2023) Burns A. and Darling N., “Peer Pressure Is NOT Peer Influence”, The Education Digest, 82:1 (2002): 4-6 https://ucolibinstruction.files.wordpress.com/2010/10/ed-article-4.pdf Department of Psychology, “Professor Sarah-Jayne Blakemore”, University of Cambridge, [https://www.psychol.cam.ac.uk/staff/professor-sarah-jayne-blakemore/ Last Accessed: 30 December 2023] Golsteyn B. H. H., Non A., and Zölitz U., “The Impact of Peer Personality on Academic Achievement”, Journal of Political Economy, 129:4 (2021): 1052–1099 https://doi.org/10.1086/712638 How friendship affects your brain – Shannon Odell [online video], TED-Ed, 16 September 2022, https://youtu.be/YmVpwXH4jhA?si=cQOV4NX6bLOmkISy, (Last Accessed: 30 December 2023) Jones T., “Brain Development During Adolescence”, Lumen Learning, [https://courses.lumenlearning.com/wm-lifespandevelopment/chapter/brain-development-during-adolescence/#footnote-2982-1/ Last Accessed: 30 December 2023] “Michael Corriero”, Virtue Foundation, [https://virtuefoundation.org/committee/michael-corriero/#:~:text=Judge%20Corriero%20is%20the%20Executive,York%20Center%20for%20Juvenile%20Justice./ Last Accessed: 30 December 2023] Sarah-Jayne Blakemore: The mysterious workings of the adolescent brain [online video], 18 September 2012, https://youtu.be/6zVS8HIPUng?si=7XIffBg_9I_xdnxk, (Last Accessed: 30 December 2023) The juvenile system is broken. Here’s what actually works. [online video], PBS NewsHour, 29 October 2021, https://youtu.be/q1fsysGy_hM?si=i7tw5YsN-AV3zb0D, (Last Accessed: 30 December 2023). The Neuroscience of the Teenage Brain—with Sarah-Jayne Blakemore [online video], The Royal Institution, 22 August 2018, https://youtu.be/yQXhFa8dRCI?si=d5tWUOtyjMZGeAXl, (Last Accessed: 30 December 2023).

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