What makes up nucleic acids biology

Chapter Population and Community Ecology. Chapter Biodiversity and Conservation. Chapter Speciation and Diversity. Chapter Natural Selection. Chapter Population Genetics. Chapter Evolutionary History. Chapter Plant Structure, Growth, and Nutrition. Chapter Plant Reproduction. Chapter Plant Responses to the Environment. Full Table of Contents. This is a sample clip. Sign in or start your free trial. JoVE Core Biology. Previous Video Next Video. Embed Share. Nucleic acids are polymers of nucleotides.

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Thank You. Please enjoy a free hour trial. In order to begin, please login. Please click here to activate your free hour trial. If you do not wish to begin your trial now, you can log back into JoVE at any time to begin. Save to playlist. Thes units are called nucleotides, and they are chemically linked to one another in a chain. The order, or sequence, of the nucleotides in DNA allows nucleic acid to encode an organism's genetic blueprint.

Related Concepts You have authorized LearnCasting of your reading list in Scitable. What impact do you think this will have on the DNA structure? RNA is usually single-stranded and is made of ribonucleotides that are linked by phosphodiester bonds. A ribonucleotide in the RNA chain contains ribose the pentose sugar , one of the four nitrogenous bases A, U, G, and C , and the phosphate group. In the cytoplasm, the mRNA interacts with ribosomes and other cellular machinery Figure 4. Figure 4.

A ribosome has two parts: a large subunit and a small subunit. The mRNA sits in between the two subunits. A tRNA molecule recognizes a codon on the mRNA, binds to it by complementary base pairing, and adds the correct amino acid to the growing peptide chain. The mRNA is read in sets of three bases known as codons. Each codon codes for a single amino acid.

In this way, the mRNA is read and the protein product is made. The rRNA ensures the proper alignment of the mRNA and the ribosomes; the rRNA of the ribosome also has an enzymatic activity peptidyl transferase and catalyzes the formation of the peptide bonds between two aligned amino acids. It carries the correct amino acid to the site of protein synthesis. It is the base pairing between the tRNA and mRNA that allows for the correct amino acid to be inserted in the polypeptide chain.

One other difference bears mention. There is only one type of DNA. There are mutliple types of RNA: Messenger RNA is a temporary molecule that transports the information necessary to make a protein from the nucleus where the DNA remains to the cytoplasm, where the ribosomes are.

Even though the RNA is single stranded, most RNA types show extensive intramolecular base pairing between complementary sequences, creating a predictable three-dimensional structure essential for their function. This is known as the Central Dogma of Life, which holds true for all organisms; however, exceptions to the rule occur in connection with viral infections.

Nucleic acids are molecules made up of nucleotides that direct cellular activities such as cell division and protein synthesis. Each nucleotide is made up of a pentose sugar, a nitrogenous base, and a phosphate group.

Without it, a cell is not able to accommodate the large amount of DNA that is stored inside. A eukaryote contains a well-defined nucleus, whereas in prokaryotes the chromosome lies in the cytoplasm in an area called the nucleoid. In prokaryotic cells, both processes occur together. What advantages might there be to separating the processes? What advantages might there be to having them occur together? Eukaryotic and prokaryotic cells : A eukaryote contains a well-defined nucleus, whereas in prokaryotes, the chromosome lies in the cytoplasm in an area called the nucleoid.

The size of the genome in one of the most well-studied prokaryotes, E. So how does this fit inside a small bacterial cell? The DNA is twisted by what is known as supercoiling. Supercoiling means that DNA is either under-wound less than one turn of the helix per 10 base pairs or over-wound more than 1 turn per 10 base pairs from its normal relaxed state. Some proteins are known to be involved in the supercoiling; other proteins and enzymes such as DNA gyrase help in maintaining the supercoiled structure.

Eukaryotes, whose chromosomes each consist of a linear DNA molecule, employ a different type of packing strategy to fit their DNA inside the nucleus. At the most basic level, DNA is wrapped around proteins known as histones to form structures called nucleosomes. The histones are evolutionarily conserved proteins that are rich in basic amino acids and form an octamer. The DNA which is negatively charged because of the phosphate groups is wrapped tightly around the histone core.

This nucleosome is linked to the next one with the help of a linker DNA. This is further compacted into a 30 nm fiber, which is the diameter of the structure. At the metaphase stage the chromosomes are at their most compact, approximately nm in width, and are found in association with scaffold proteins.

Eukaryotic chromosomes : These figures illustrate the compaction of the eukaryotic chromosome. In interphase, eukaryotic chromosomes have two distinct regions that can be distinguished by staining.

The tightly packaged region is known as heterochromatin, and the less dense region is known as euchromatin. Heterochromatin usually contains genes that are not expressed, and is found in the regions of the centromere and telomeres.

The euchromatin usually contains genes that are transcribed, with DNA packaged around nucleosomes but not further compacted. RNA is the nucleic acid that makes proteins from the code provided by DNA through the processes of transcription and translation.