Summary In nature, populations are usually evolving, that is, the genetic make-up of any population is dynamic and changing over the course of many generations. One of the key ways that scientists study the evolution is to assess what a population looks like when it is not evolving, i.e. in an “idealised” state. This idealised …
The structure of genes and the control of gene expression involve encoded nucleotide sequences and a complex regulatory network of transcription factors. Keep reading for more detailed A-level Biology revision! Summary The way in which DNA transmits its information to the cell is through encoding proteins. The genome (all the DNA in the cell) not …
Summary The Human Genome Project The Human Genome Project was an international research program involving over 1000 scientists. It was a publically funded project that began in the late 1980s, aiming to map and understand all the genes in the human genome. This can be carried out by determining the order (also called the sequence) …
Pyruvate oxidation and the Krebs cycle are key metabolic pathways in cellular respiration that convert the products of glycolysis into acetyl-CoA, which enters the Krebs cycle and generates ATP, NADH, and FADH2 through a series of oxidation-reduction reactions. Summary of Pyruvate oxidation and the Krebs cycle In living organisms, glucose is the molecule that is …
Summary Respiration is the process of breaking down organic molecules to harvest chemical energy. For organisms such as humans, it involves taking in food, breaking it down, and turning into useful energy that our cells can use to perform many tasks. This is most efficiently done in the presence of oxygen to make an important …
Summary What is Glycolysis? Glycolysis the first step of cellular respiration. It describes a sequence of reactions that break down carbohydrates into smaller molecules. Broadly, glycolysis breaks down a glucose molecule and forms 2 pyruvate molecules, with the release of two molecules of ATP. Glycolysis evolved a long time ago and is utilised by the …
Summary Gene therapy is the repair or replacement of faulty genes with healthy versions. It is carried out by introducing DNA containing the functional gene into a patient, to correct a disease-causing mutation. Gene therapy was initially concocted in 1972, but has had limited success in treating human diseases. This can be largely attributed to …
DNA, often described as the “molecule of life,” holds the key to understanding the core processes governing the existence of all living organisms. At the heart of this biological marvel lies the Central Dogma, a fundamental concept in molecular biology first proposed by Francis Crick in the 20th century. The Central Dogma outlines the flow …
Summary Nucleic acid is a term covering both DNA and RNA molecules, the key macromolecules for the continuation of life. DNA and RNA are similar, and both store and transmit critical information. However, they do have some stark differences, allowing them to perform distinct functions within the cell. The key differences are in the sugar …
The intricacies of DNA replication, the remarkable process by which genetic information is faithfully duplicated, form the cornerstone of life as we know it. This article An Introduction to DNA replication, delves into the essential concept of DNA replication, unraveling the molecular machinery and biological significance that underpin the accurate transmission of genetic instructions from …
