User contributions for Yasir AL-Bayati
From WikiLectures
3 April 2025
- 11:5611:56, 3 April 2025 diff hist +4,856 N Methods of cell fractionation, electrophoresis of nucleic acids and proteins. Created page with "__NOTOC__ Understanding the structure and function of cells and biomolecules often requires isolating specific cellular components or analyzing nucleic acids and proteins. Two essential laboratory techniques used for these purposes are **cell fractionation** and **electrophoresis**. == Cell fractionation == '''Cell fractionation''' is the process of breaking open cells and separating their components based on size, density, and other physical properties. It al..." current
- 11:5411:54, 3 April 2025 diff hist +4,403 N MRNA structure, post-transcriptional modifications (cap, poly A, splicing). Created page with "__NOTOC__ '''Messenger RNA (mRNA)''' is a type of RNA that serves as the intermediate template between DNA and protein synthesis. It carries genetic information transcribed from genes and is translated by ribosomes into a specific amino acid sequence. In eukaryotes, primary mRNA (pre-mRNA) undergoes several essential **post-transcriptional modifications** before becoming a mature, translatable molecule. == Structure of mRNA == A typical eukaryotic mature m..." current
- 11:5211:52, 3 April 2025 diff hist +5,102 N DNA repair - BER, NER, MMR, direct repair of modified bases. Created page with "__NOTOC__ '''DNA repair''' is a vital set of processes by which cells identify and correct damage to the DNA molecules that encode their genomes. Every day, cells are exposed to endogenous and exogenous agents (e.g., reactive oxygen species, UV light, radiation) that damage DNA. Without repair, this damage can lead to mutations, genomic instability, cancer, or cell death. To maintain genomic integrity, cells employ various repair pathways, including **base excision rep..." current
- 11:2811:28, 3 April 2025 diff hist +5,423 N Classification of human genomic DNA according to repetitiveness and function, pseudogenes, transposons. Created page with "NOTOC_ The human genome is a complex and diverse structure composed of different classes of DNA sequences, which vary significantly in terms of *function, **repetitiveness, and **evolutionary origin*. While only a small fraction of genomic DNA directly encodes proteins, the rest contributes to regulation, structural organization, and evolutionary potential. Some sequences, like pseudogenes and transposons, are remnants of evolutionary history with varying de..." current
- 11:2511:25, 3 April 2025 diff hist +6,165 N Proteolysis-dependent signaling pathways, examples. HIF signaling role in response to hypoxia. Created page with "__NOTOC__ '''Proteolysis-dependent signaling pathways''' are unique cellular mechanisms in which specific signals are transmitted through the targeted cleavage of proteins. Unlike phosphorylation-based signaling, which relies on reversible modifications, proteolytic signaling often involves irreversible activation or degradation of proteins. This form of regulation is crucial in processes such as cell differentiation, apoptosis, immune responses, and adaptation to envir..." current
- 11:2111:21, 3 April 2025 diff hist +6,126 N Mechanism and significance of reversible phosphorylation in signal transduction. Created page with "__NOTOC__ '''Reversible phosphorylation''' is one of the most critical regulatory mechanisms in eukaryotic cells. It refers to the addition (phosphorylation) and removal (dephosphorylation) of phosphate groups on proteins, catalyzed by protein kinases and protein phosphatases, respectively. This post-translational modification functions as a molecular switch in numerous biological processes, particularly in signal transduction pathways. It enables cells to..." current
- 11:1711:17, 3 April 2025 diff hist +6,328 N G-proteins - structure, activation, function. Created page with "__NOTOC__ '''G-proteins''', or guanine nucleotide-binding proteins, are a family of molecular switches that play an essential role in transducing extracellular signals into intracellular responses. They are involved in various physiological processes including vision, olfaction, neurotransmission, metabolism, and hormone signaling. G-proteins act as key intermediaries in signaling pathways initiated by G-protein-coupled receptors (GPCRs), the largest..." current
