Part 2 book “MCAT biochemistry review 2019-2020” has contents: RNA and the genetic code, biological membranes, carbohydrate metabolism I - glycolysis, glycogen, gluconeogenesis, and the pentose phosphate pathway, carbohydrate metabolism II - aerobic respiration, lipid and amino acid metabolism, bioenergetics and regulation of metabolism. | In This Chapter The Genetic Code Types of RNA Codons Mutations Transcription Mechanism of Transcription Posttranscriptional Processing Translation The Ribosome Mechanism of Translation Posttranslational Processing Control of Gene Expression in Prokaryotes Operon Structure Inducible Systems Repressible Systems Control of Gene Expression in Eukaryotes Transcription Factors Gene Amplification Regulation of Chromatin Structure Concept Summary Chapter Profile The content in this chapter should be relevant to about 15% of all questions about biochemistry on the MCAT. This chapter covers material from the following AAMC content categories: 1B: Transmission of genetic information from the gene to the protein 5D: Structure, function, and reactivity of biologically-relevant molecules Introduction Hepatitis C virus (HCV) continues to be a major cause of cirrhosis and liver failure in the United States. Usually associated with intravenous drug use, hepatitis C causes ongoing damage and inflammation in the liver, leading to the formation of scar tissue that replaces the normal cells of the organ. Over time, this buildup of scar tissue makes the liver unable to keep up with the metabolic demands of the body, and liver failure ensues. To fight this virus, infected hepatocytes release interferon, a peptide signal that—as the name suggests—interferes with viral replication. Because viruses must hijack the host cell’s machinery to replicate, one way the body can limit the spread of the virus is by shutting off the processes of transcription and translation. Interferon not only curtails these processes in virally infected cells, but also induces the production of RNase L, which cleaves RNA in cells to further reduce the ability of the virus to replicate. Coupled with other immune defenses, interferon thus serves as an efficient mechanism to protect the body from viral pathogens. Even in normal, healthy cells, the first step in expressing .
