Ribonucleic acid or RNA is a polymeric molecule made up of one or more nucleotides. A polymeric molecule is a very large molecule that is chain- like. It is made up of monomers, which are smaller molecules. A strand of RNA can be thought of as a chain with a nucleotide at each chain link. Whereas, a nucleotide is a group of any type of molecules that are linked together because they form the “building blocks” of DNA (also known as deoxyribonucleic acid, and it is the carrier of genetic information.) Messenger RNA, which is called mRNA, carries the genetic information copied from DNA. Transfer RNA, which is called tRNA is the key to deciphering the code words in mRNA that forms a series of three-base code words. An enzyme is a substance that
In order to do this a polymer of DNA “unzips” into its two strands, a coding strand (left strand) and a template strand (right strand). Nucleotides of a molecule known as mRNA (messenger RNA) then temporarily bonds to the template strand and join together in the same way as nucleotides of DNA. Messenger RNA has a similar structure to that of DNA only it is single stranded. Like DNA, mRNA is made up of nucleotides again consisting of a phosphate, a sugar, and an organic nitrogenous base. However, unlike in DNA, the sugar in a nucleotide of mRNA is different (Ribose) and the nitrogenous base Thymine is replaced by a new base found in RNA known as Uracil (U)3b and like Thymine can only bond to its complimentary base Adenine. As a result of how it bonds to the DNA’s template strand, the mRNA strand formed is almost identical to the coding strand of DNA apart from these
1. Histone modifications can effect transcription by altering the chromatin structure or the interaction with other regulatory proteins. Addition of positive or negative charges through the modifications disrupts the electrostatic interaction between the histones and DNA, which modulates the chromatin structure and therefore, the accessibility of DNA to the regulatory proteins. DNA methylation is an epigenetic modification which can influence the interaction between transcription factors and CpG dinucleotides, chromatin structure or binding between methylated DNA and methylation recognition factors.
The study of nucleic acids has now become a fruitful and dynamic scientific enterprise. Nucleic acids are of unique importance in biological systems. Genes are made up of deoxyribonucleic acid or DNA, and each gene is a linear segment, or polymer, of a long DNA molecule. A DNA polymer, or DNA oligonucleotide, contains a linear arrangement of subunits called nucleotides. There are four types of nucleotides. Each nucleotide has three components; a phosphate group, a sugar and a base that contains nitrogen within its structure. The sugar moiety in DNA oligonucleotides is always dexoyribose, and there are four alternative bases: adenine (A), thymine (T), guanine (G), and cytosine (C). The phosphate groups and the deoxyribose sugars form the backbone of each DNA stand. The bases are joined to the deoxyribose sugar and stick out to the side. Both oligomers, DNA and RNA, consist of 5’->3’ phosphodiester-linked nucleotide units that are composed of a 2’-deoxy-D-ribose (DNA) or D-ribose (RNA) in their furanose forms and a heteroaromatic nucleobase (A, T, G, and C; A, U, G, C), and the resulting oligonucleotide chain is composed of a polar, negatively charged sugar-phosphate backbone and an array of hydrophobic nucleobases. The amphiphilic nature of these polymers dictates the assembly and maintenance of secondary and tertiary structures the oligonucleotides can form. In the DNA duplex structure, genetic information is stored as a linear nucleotide code. This code can be accessed and replicated. RNA, or ribonucleic acid, is another structurally related essential biopolymer. RNA differs from DNA in having the sugar ribose in place of the deoxyribos...
This New York Times article, “A Powerful New Way to Edit DNA” by Andrew Pollack talks about the molecular system called Crispr, also known as Clustered Regularly Interspaced Short Palindromic Repeats. Crispr was first discovered in the late 1980’s by scientists who noticed unusual repeated DNA sequences next to a gene that they were studying in bacteria. However, their significance was unknown until it became possible to sequence the entire genome of bacteria, at which time, scientists noticed that these repeated DNA sequences appeared in many bacterial species. It wasn’t until 2007, when researchers working for a company that supplied bacterial cultures used in making cheese and yogurt, confirmed the hypothesis that Crispr worked as an immune system in bacteria to fight off viruses.
Analysis of Transcript - Young Ones Introduction: I have chosen to analyse the beginning of the first episode in the first series of the 80’s TV comedy ‘The Young Ones’. This particular text appeals to me because it is important in how it introduces the characters, as this is the first time the audience ever meet them. Relative Status: Rick and Neil are both students living in the same house; therefore their status should be equal though both are striving for dominance. Rick is defiantly the more dominant of the two, due to his extrovert personality. Both characters are self-centred, for instance, at the beginning of the scene; Neil delivers a monologue where he talks about himself a lot.
Chemistry dictates the structure of DNA. DNA is a polymer of monomers called nucleic acids. These are made of a nitrogenous base, a phosphate group and a sugar. It is the negative charge on the phosphate group that makes DNA an acid. There are 4 different bases: adenine, thymine, guanine and cytosine. In groups of three, these four bases can code for any protein coded for in an organism’s genome. Two strands of nucleic acids stack on top of each other in a double helix. The backbone of the nucleic acids consists of the interaction between phosphate groups and the hydroxide groups of nucleic acids. These are held together by covalent bonds called phosphodiester bonds. The helix itself is held together by hydrogen bonds. Although h...
Chapter four is about nature, nurture, and human diversity, we learn about genes, DNA, the effects our environment has on us. The chapter opens with an introduction to what makes us, us, our genes. Genes are small segments of DNA, our biochemical units of heredity that make up the chromosomes. Our 20,000 to 25,000 genes are either active or inactive, they are “turned on” by environmental events. DNA (deoxyribonucleic acid) is a complex molecule that contains our genetic information. Chromosomes are the donated parts from our parents, and they contain our DNA strands, in total we have 46, 23 from our mother and 23 from our father. Our genome, instruction for making an organism, containing all genetic material in the chromosomes, is what makes us human, rather than another living organism.
There is a two step process involved in order for the genes to be used. The first half of this process is called transcription. DNA is made up of four nucleotides: adenine, cytosine, guanine, and thiamin. These nucleotides are in pairs in the DNA and their order is very important because it dictates how the gene will be expressed. During transcription RNA, a similar molecule to DNA, comes in and makes the compliment copy of the DNA sequence. The second half of this process is called translation. During translation the RNA is used to make amino acids, which are then used to make a protein. Not all of the RNA is used to make the amino acids, only the sections which are between the start and stop signals. Then sets of three nucleotides called codons are used to make specific amino acids. Different sets of amino acids code for different proteins.
The diversity and the unity of life are equally meaningful and striking aspects of our Earth (Dobzhansky, 1973). Although an astounding 1.2 million species have already been identified, it is estimated that another 8.7 million are yet to be discovered and classified (Mora et al., 2011). By understanding what unifies us –our genes, our understanding of the organisms we share our planet with will continue to grow.
Almost all biology students learn the fundamentals of gene expression, DNA contains information which is transcribed into RNA to create protein. Students however, are not taught of RNA Interference, the biological process where RNA molecules inhibit a gene’s expression, RNAi for short. While RNAi is a fairly new discovery, its use in modern biological research is groundbreaking. RNA Interference works by binding Double-stranded RNA molecules (siRNA) to a complementary messenger RNA. The enzymes Dicer and Slicer then cleave the chemical bonds which hold the messeger RNA in place and prevent it from delivering protein silencing instructions thus, the term, Gene Silencing. This phenomenon was first discovered by Richard Jorgensen in 1990 when he was trying to produce deeper purple colored petunias by introducing more purple pigment genes to the flower. To his surprise, the purple petunia turned completely white and got the opposite of his predicted result. At the time Jorgensen coined this effect, “Cosuppression”. It was not until 1998 that Andrew Fire and Craig, C Mello explained the process of RNAi and discovered its use in Caenorhabditis elegans (C. Elegans). In 2006 Fire and Mello won the Nobel Prize in Physiology or Medicine “for their discover of RNA Interference – gene silencing by double stranded RNA”. They utilized the nematode, C. Elegans due to its whole genome being sequenced. This unique characteristic allows for every gene to be tested
...transcript is translated into an amino acid sequence. Which is the genetic code. Each combination of three mRNA nucleotides in a codon. Each codon codes for a specific amino acid. For example, the start codon is AUG while the stop codons are UAA, UAG, and UGA. During, translation tRNA anti-codons pair with their corresponding mRNA codon. The amino acids are joined to form polypeptides. The polypeptide folds and bonds with other polypeptides, and functions as a complete structure of a protein.
A genome is the make up of all the genetic material in an organism. It is the entire hereditary instructions for building, running and maintaining an organism and also transferring DNA onto offspring (Refer to image 3). The genome in most organisms is made up of a chemical called Deoxyribonucleic acid (DNA). Genes are a set of instructions that determine what the organism is like, in its environment . Genes are found in the genome. The genome is made up of three components; chromosomes, which contain genes, which are m...
Micro RNAs (miRNA) are small non-coding RNAs that are involved in regulating the translation of messenger RNA (mRNA). Over 1000 miRNAs have been identified which control approximately 60% of the protein coding genes1. The miRNAs are on average 23 nucleotides long, with nucleotides 2-7 acting as the seed region. The seed region is needed for specific mRNA interactions and mutations occur in this region it can disrupt the miRNA, mRNA Watson-Crick base pairing2.
Deoxyribonucleic acid or as it has become known DNA is defined in our text as “The basic building code for all of the human body’s chromosomes” it also states that DNA is found in every cell in a person’s body and is unique as fingerprints to each individual. The first time DNA was used according to “History of DNA Testing in Criminal Cases” written by J. Hirby. “DNA was first used in a criminal case in England in 1986. DNA samples collected from the men living and working within the neighborhood of two rape and murder scenes resulted in two positive outcomes. The one man original convicted was proved to be innocent and the guilty criminal was caught. One year later, DNA was first used in a United States criminal case in Florida. The forensic evidence collected from a rape victim was positively matched to a suspect’s DNA and when presented in court, the suspect was found guilty of the crime.” DNA, over the last twenty years has become one of the most well-known types of forensic evidence tools.