RNA (Ribonucleic Acid) PDF

Cagayan State University –Carig Campus AD OPTIMUM EDUCANS RNA (Ribonucleic acid) RNA is a polymer of ribonucleotides linked together by 3’-5’ phosphodiester linkage The main job of RNA is to transfer the genetic code need for the creation of proteins from...

Cagayan State University –Carig Campus AD OPTIMUM EDUCANS RNA (Ribonucleic acid) RNA is a polymer of ribonucleotides linked together by 3’-5’ phosphodiester linkage The main job of RNA is to transfer the genetic code need for the creation of proteins from the nucleus to the ribosome. This process prevents the DNA from having to leave the nucleus. This keeps the DNA and Although single stranded, RNA is genetic code protected from damage. not always linear. It has the ability to fold into complex three Without RNA, proteins could never be made. dimensional shapes and form hairpin loops. 1st SEMESTER School 1 Year 2 2025 Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Types of RNA 1st SEMESTER School 2 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Seeing RNA at the nanoscale Strand Of RNA On DNA Fragment. 1st SEMESTER School 3 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS TRIPLET CODONS The triplet of nucleotide bases in the mRNA that codes for a particular amino acid is called a codon. Termination of translation of the mRNA is signalled by the presence of one of the three stop or termination codons. 1st SEMESTER School 4 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Human Genome Project The Human Genome Project (HGP) was the international, collaborative research program whose goal was the complete mapping and understanding of all the genes of Integral pieces of our cellular human beings. machinery have been altered by All the genes together are known as coming into contact with viruses. "genome." 1st SEMESTER School 5 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS The HGP has revealed that there are probably about 20,500 human genes. The completed human sequence can now identify their locations. This ultimate product of the HGP has given the world a resource of detailed information about the structure, organization and function of the complete set of human genes. This information can be thought of as the basic set of inheritable "instructions" for the development and function of a human being. 1st SEMESTER School 6 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Gene Therapy Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. Researchers are testing several approaches to gene therapy, including: Replacing a mutated gene that causes disease with a healthy copy of the gene. Inactivating, or “knocking out,” a mutated gene that is functioning improperly. Introducing a new gene into the body to help fight a disease.1st SEMESTER School 7 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be safe and effective. Gene therapy is currently being tested only for diseases that have no other cures. 1st SEMESTER School 8 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS The treatment, which was first tested in humans in 1990, can be performed inside or outside of the body. When it’s done inside the body, doctors may inject the virus carrying the gene in question directly into the part of the body that has defective cells. 1st SEMESTER School 9 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS This is useful when only certain populations of cells need to be “fixed.” For example, researchers are using it to try to treat Parkinson's disease, because only part of the brain must be targeted. This approach is also being used to treat eye diseases and hemophilia, an inherited disease that leads to a high risk for excess bleeding, even from minor cuts. 1st SEMESTER School 10 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Out-of-the-body gene therapy has already been used to treat severe combined immunodeficiency—also referred to as SCID or boy-in-the- bubble syndrome—where patients are unable to fight infection and die in childhood. In this type of gene therapy, scientists use retroviruses, of which HIV is an example. These agents are extremely good at inserting their genes into the DNA of host cells. More than 30 patients have been treated for SCID, and more than 90 percent of those children have been cured of their disorder—an improvement over the 50 percent chance of recovery offered by bone marrow transplants. 1st SEMESTER School 11 Year 2 2025 Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Timing is everything when it comes to treating this rare genetic disorder that causes complete immunodeficiency 1st SEMESTER School 12 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS A risk involved with retroviruses is that they may stitch their gene anywhere into DNA, disrupting other genes and causing leukemia. Unfortunately, five of the 30 children treated for SCID have experienced this complication; four of those five, however, have beaten the cancer. Researchers are now designing delivery systems that will carry a much lower 1st SEMESTER School 13 Year 2 risk of causing this condition. 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS DNA Mutation DNA mutations are permanent changes in the DNA sequence of a gene. Mutations range in their severity. Some damage the way a cell or whole organism functions, or even cause lethality, while others have no effect. Mutations also range in the amount of DNA altered. They can involve from a single nucleotide up to large segments of chromosomes. 1st SEMESTER School 14 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Inherited: parents that have mutations can pass them to their offspring. Germ line mutations: are present in every cell of an individual, including the egg or sperm used in the production of offspring. 1st SEMESTER School 15 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS De novo (new) mutations: occur by chance in one or a few eggs or sperm, or just after fertilization, and are NOT present in every cell of a parent. These explain situations where a child has a genetic disorder that is unseen in the family history. Acquired: environmental agents, called mutagens, can alter DNA. An example of a common mutagen are the UV wavelengths in sunlight associated with skin cancer (see image). Acquired mutations are typically not passed to offspring but can be if they alter DNA sequences in egg or sperm. 1st SEMESTER School 16 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Types of mutation Insertion/Duplication/Deletion: the addition or subtraction of nucleotides from DNA sequence. They can be as small as single nucleotides or large enough to visualize on a chromosome and involve tens to hundreds of thousands of nucleotides. Point Mutation: the change in one nucleotide for another. For example, an “A” becomes a “T”. 1st SEMESTER School 17 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Translocation: the movement of a segment of DNA from one chromosome to another. Inversion: the 180° flip of a DNA segment so that that it is reversed compared to the original structure. Ultimately whether or not a particular mutation causes a detrimental effect is due to the location of the mutation within a gene (or genes) as well as the significance of that gene’s function. 1st SEMESTER School 18 Year 2 2025 19  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS DNA Repair DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. 1st SEMESTER School 20 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Direct repair of thymine dimers UV-induced thymine dimers can be repaired by photoreactivation, in which Examples of DNA damage energy from visible light is used to split induced by radiation and the bonds forming the cyclobutane ring. chemicals 1st SEMESTER School 21 Year 2 2025 Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Nucleotide-excision repair of thymine dimers Damaged DNA is recognized and then cleaved on both sides of a thymine dimer by 3′ and 5′ nucleases. Unwinding by a helicase results in excision of an oligonucleotide containing the damaged bases. The resulting gap is then filled by DNA polymerase and sealed by ligase. 1st SEMESTER School 22 Year 2 2025 Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Mismatch repair in mammalian cells Mismatch repair in mammalian cells is similar to E. coli, except that the newly replicated strand is distinguished from the parental strand because it contains strand breaks. MutS and MutL bind to the mismatched base and direct excision of the DNA between the strand break 1stand the School SEMESTER 23 Year 2 2025 Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Postreplication repair The presence of a thymine dimer blocks replication, but DNA polymerase can bypass the lesion and reinitiate replication at a new site downstream of the dimer. The result is a gap opposite the dimer in the newly synthesized DNA strand. In recombinational repair, this gap is filled by recombination with the undamaged parental strand. Although this leaves a gap in the previously intact parental strand, the gap can be filled by the actions of polymerase and ligase, using the intact daughter strand as a template. Two intact DNA molecules are thus formed, and the remaining thymine dimer eventually can be removed by excision repair. 1st SEMESTER School 24 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS DNA Cloning DNA cloning is the process of making multiple, identical copies of a particular piece of DNA. DNA cloning is the starting point for many genetic engineering approaches to biotechnology research. Large amounts of DNA are needed for genetic engineering. Multiple copies of a piece of DNA can be made either by using polymerase chain reaction (PCR) or by 1st SEMESTER School 25 Year 2 cloning DNA in cells. 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS The term ‘cloning’ is also used to describe other laboratory processes: Reproductive cloning is the process of making a genetically identical copy of an organism. Therapeutic cloning is the process of making multiple copies of a cell to treat a disease. 1st SEMESTER School 26 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS DNA cloning is used to create a large number of copies of a gene or other piece of DNA. The cloned DNA can be used to : Work out the function of the gene Investigate a gene’s characteristics (size, expression, tissue distribution) Look at how mutations may affect a gene’s function Make large concentrations of the protein coded for by the gene 1st SEMESTER School 27 Year 2 2025 Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Cloned monkeys Zhong Zhong and Hua Hua are seen at the non- human primate facility 1st SEMESTER School 28 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS DNA Data Storage “The libraries of the future will be made of DNA.” Various scientists have begun to explore the possibility of using DNA to store information, called Nuclear Acid Memory (NAM). This would involve the data being “translated” into the letters GATC, the base nucleic acids of DNA. DNA strands would then be created which could be translated back into the “original” by being sequenced. Researchers recently stored archival-quality versions of music by Miles Davis and Deep Purple and also 1st SEMESTER School 29 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS DNA is durable and increasingly easy to produce and read. It will keep for thousands of years in the right storage conditions. DNA might be stored anywhere that is dark, dry, cold, and arguably would not take up a great deal of room Tens of years from now, 100 It remains to be seen whether future years from now, 1,000 years from storage and writing will be as easy to now [people] will be able to take access, and who will be in control of that speck of DNA and read it humanity’s information and memory in back on a machine that reads the coming decades and centuries. DNA. 1st SEMESTER School 30 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS conclusion DNA is very important for life. It can replicate well, which means that the next generation will retain the characteristics of the parents. It is capable of change, which means that it provides for variation and was crucial for evolution to occur. It also codes for proteins that help express genes and traits of the organism. 1st SEMESTER School 31 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Different parts of chromosome 1. Pellicle and Matrix 2. Chromatids, Chromonema and Chromomeres 3. Centromeres 4. Secondary Constriction 5. Satellite 6. Telomere. 1st SEMESTER School 32 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS Structure of chromosome contains Sister chromatids Centromere DNA telomeres 1st SEMESTER School 33 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS karyolymph karyolymph kar·y·o·lymph (kār'ē- ə-lĭmf') n. The colorless gel or liquid component of the cell nucleus in which stainable elements are suspended, now known to be euchromatin. Also called nuclear hyaloplasm. 1st SEMESTER School 34 Year 2 2025  Cagayan State University –Carig Campus AD OPTIMUM EDUCANS karyohexis Karyorrhexis (from Greek κάρυον karyon, "kernel, seed or nucleus", and ῥῆξις rhexis, "bursting") is the destructive fragmentation of the nucleus of a dying cell whereby its chromatin is distributed irregularly throughout the cytoplasm. 1st SEMESTER School 35 Year 2 2025 Nucleu s 36