Deamination
Deamination - Related Videos
02:23
RNA Editing
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2020
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
02:25
Overview of DNA Repair
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2020
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage. Chemically...
12:34
DNA Methylation: Bisulphite Modification and Analysis
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Cited by 75 •
2011
The gold standard for DNA methylation analysis is genomic sequencing of bisulphite converted DNA. This method takes advantage of the increased sensitivity of cytosine compared with 5-methylcytosine (5-MeC) to bisulphite deamination under acidic conditions. Unmethylated cytosines can be distinguished from methylated cytosines after PCR amplification of the target genomic DNA.
01:54
Base Excision Repair
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2020
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template. The first step of...
02:36
Transfer RNA Synthesis
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2020
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases. Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
FAQs
Oxidative and hydrolytic routes remove amino groups through different reaction modes, but both alter the original molecule’s nitrogen content. In amino-acid metabolism, the reaction can release ammonia or transfer nitrogen, depending on the reaction context. This distinction matters because it links deamination to different ways cells process nitrogen while preserving a carbon skeleton for subsequent metabolic use.
The remaining carbon skeleton is not merely a reaction residue: it provides the carbon framework that can enter other metabolic pathways. Consequently, amino-group removal separates two aspects of amino-acid breakdown, nitrogen handling and carbon utilization. Tracking these products helps explain how cells can route amino-acid components toward nitrogen excretion while retaining metabolic value in the carbon portion.
Hydrolytic deamination of nucleic-acid components can change a normal base into another base, such as cytosine into uracil or adenine into hypoxanthine. If the altered base remains when DNA replicates, it can pair incorrectly and produce a mismatch. Thus, the reaction provides a direct chemical route from molecular damage to potential mutation formation.
Their products, uracil and hypoxanthine, differ from the original bases and can disrupt expected base-pairing relationships. The resulting mismatches challenge the accuracy of DNA replication and create a need for DNA repair. Studying which base changes arise therefore helps connect spontaneous chemical reactions with mutation formation and genome maintenance.
Following whether an amino-group reaction releases ammonia or transfers nitrogen clarifies how nitrogen moves during amino-acid breakdown. Examining the associated carbon skeleton adds a second readout, showing how the non-nitrogen portion enters metabolic pathways. Together, these outcomes help researchers relate molecular reactions to nitrogen excretion and broader metabolic organization.
These reactions provide a framework for investigating amino-acid breakdown, nitrogen excretion, DNA repair, mutation formation, and the molecular basis of some diseases. The same topic therefore connects metabolism with genetic stability rather than belonging to only one pathway. Comparing its metabolic and nucleic-acid consequences can reveal which biological process is affected and what outcome follows.