Showing posts with label DNA strand. Show all posts
Showing posts with label DNA strand. Show all posts
Thursday, June 23, 2011
DNA Strand
Bio-Synthesis continued to provide quality DNA products and services for the research community, but it has also become a world leader in providing custom peptide products and services. We offer comprehensive services for polyclonal antibody production with large selection for host animals.
DNA Strand Hypothesis
The immortal DNA strand hypothesis was proposed in 1975 by John Cairns as a mechanism for adult stem cells to minimize mutations in their genomes. This hypothesis proposes that instead of segregating their DNA during mitosis in a random manner, adult stem cells divide their DNA asymmetrically, and retain a distinct template set of DNA strands (parental strands) in each division. By retaining the same set of template DNA strands, adult stem cells would pass mutations arising from errors in DNA replication on to non-stem cell daughters that soon terminally differentiate (end mitotic divisions and become a functional cell).
DNA Strands
In the label-retention assay, the goal is to mark 'immortal' or parental DNA strands with a DNA label such as tritiated thymidine or bromodeoxyuridine (BrdU). These types of DNA labels will incorporate into the newly-synthesized DNA of dividing cells during S phase. A pulse of DNA label is given to adult stem cells under conditions where they have not yet delineated an immortal DNA strand.
For more information visit: www.biosyn.com
Saturday, August 9, 2008
Protein Biosynthesis
Protein Biosynthesis (synthesis) is the process in which cells build proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription which are then used for translation. Protein biosynthesis, although very similar, differs between prokaryotes and eukaryotes.
Amino acid synthesis
Amino acids are the monomers which are polymerized to produce proteins. Amino acid synthesis is the set of biochemical processes (metabolic pathways) which build the amino acids from carbon sources like glucose. Not all amino acids may be synthesised by every organism, for example adult humans have to obtain 8 of the 20 amino acids from their diet.
Transcription
Transcription is the process by which an mRNA template, encoding the sequence of the protein in the form of a trinucleotide code, is transcribed from the genome to provide a template for translation. Transcription copies the template from one strand of the DNA double helix, called the template strand.Transcription can be divided into 3 stages: Initiation, Elongation and Termination, each regulated by a large number of proteins such as transcription factors and coactivators that ensure the correct gene is transcribed in response to appropriate signals.The DNA strand is read in the 3' to 5' direction and the mRNA is transcribed in the 5' to 3' direction by the RNA polymerase.
Translation
The synthesis of proteins is known as translation. Translation occurs in the cytoplasm where the ribosomes are located. Ribosomes are made of a small and large subunit which surrounds the mRNA. In translation, messenger RNA (mRNA) is decoded to produce a specific polypeptide according to the rules specified by the genetic code. This uses an mRNA sequence as a template to guide the synthesis of a chain of amino acids that form a protein. Translation is necessarily preceded by transcription. Translation proceeds in four phases: activation, initiation, elongation and termination (all describing the growth of the amino acid chain, or polypeptide that is the product of translation).In activation, the correct amino acid (AA) is joined to the correct transfer RNA (tRNA). While this is not technically a step in translation, it is required for translation to proceed. The AA is joined by its carboxyl group to the 3' OH of the tRNA by an ester bond.
Amino acid synthesis
Amino acids are the monomers which are polymerized to produce proteins. Amino acid synthesis is the set of biochemical processes (metabolic pathways) which build the amino acids from carbon sources like glucose. Not all amino acids may be synthesised by every organism, for example adult humans have to obtain 8 of the 20 amino acids from their diet.
Transcription
Transcription is the process by which an mRNA template, encoding the sequence of the protein in the form of a trinucleotide code, is transcribed from the genome to provide a template for translation. Transcription copies the template from one strand of the DNA double helix, called the template strand.Transcription can be divided into 3 stages: Initiation, Elongation and Termination, each regulated by a large number of proteins such as transcription factors and coactivators that ensure the correct gene is transcribed in response to appropriate signals.The DNA strand is read in the 3' to 5' direction and the mRNA is transcribed in the 5' to 3' direction by the RNA polymerase.
Translation
The synthesis of proteins is known as translation. Translation occurs in the cytoplasm where the ribosomes are located. Ribosomes are made of a small and large subunit which surrounds the mRNA. In translation, messenger RNA (mRNA) is decoded to produce a specific polypeptide according to the rules specified by the genetic code. This uses an mRNA sequence as a template to guide the synthesis of a chain of amino acids that form a protein. Translation is necessarily preceded by transcription. Translation proceeds in four phases: activation, initiation, elongation and termination (all describing the growth of the amino acid chain, or polypeptide that is the product of translation).In activation, the correct amino acid (AA) is joined to the correct transfer RNA (tRNA). While this is not technically a step in translation, it is required for translation to proceed. The AA is joined by its carboxyl group to the 3' OH of the tRNA by an ester bond.
Wednesday, July 2, 2008
RNA Synthesis
With over 20 years experience in custom synthesis for the biomedical research communities, Biosyn has developed the expertise to deliver custom synthesized RNA with quality that meets all your RNAi, siRNA, sh RNA and other RNA projects.
RNA Synthesis
RNA synthesis is said to proceed in the 5′ to 3′ direction, reflecting the fact that the attachment of new nucleotides always occurs at the 3′ hydroxyl group of the growing RNA chain. RNA synthesis goes through phases that are typical of polymerization processes: initiation, elongation, and termination, yielding an RNA product of defined size and sequence.
Common RNA
Before the nucleotides are linked together, they exist separately as ribonucleoside tripolyphosphate (NTPs). As shown below, the NTP's contain one of the four common RNA bases, A, C, G, and U, linked to a five-carbon ribosome sugar, linked, in turn, to a chain of three phosphate groups. During RNA synthesis, a covalent, "phosphorescent" bond is formed between one of the three phosphate groups on one NTP and a hydroxyl group on another. The two other phosphate groups that were part of the original NTP are released.
Nucleotides
RNA, like DNA, is a polymer of nucleotides. Each nucleotide consists of a sugar that is attached to a phosphate group and any one of four bases. The RNA polymerase, as it builds the chain of nucleotides, processes only one of the two complementary strands of DNA. This DNA strand is referred to as the template strand. The least confusing name for the other DNA strand is "the non-template strand.
RNA Synthesis
RNA synthesis is said to proceed in the 5′ to 3′ direction, reflecting the fact that the attachment of new nucleotides always occurs at the 3′ hydroxyl group of the growing RNA chain. RNA synthesis goes through phases that are typical of polymerization processes: initiation, elongation, and termination, yielding an RNA product of defined size and sequence.
Common RNA
Before the nucleotides are linked together, they exist separately as ribonucleoside tripolyphosphate (NTPs). As shown below, the NTP's contain one of the four common RNA bases, A, C, G, and U, linked to a five-carbon ribosome sugar, linked, in turn, to a chain of three phosphate groups. During RNA synthesis, a covalent, "phosphorescent" bond is formed between one of the three phosphate groups on one NTP and a hydroxyl group on another. The two other phosphate groups that were part of the original NTP are released.
Nucleotides
RNA, like DNA, is a polymer of nucleotides. Each nucleotide consists of a sugar that is attached to a phosphate group and any one of four bases. The RNA polymerase, as it builds the chain of nucleotides, processes only one of the two complementary strands of DNA. This DNA strand is referred to as the template strand. The least confusing name for the other DNA strand is "the non-template strand.
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