Which monomers make up rna




















The other type of nucleic acid, RNA, is mostly involved in protein synthesis. In eukaryotes, the DNA molecules never leave the nucleus but instead use an intermediary to communicate with the rest of the cell. Each nucleotide is made up of three components:. Each nitrogenous base in a nucleotide is attached to a sugar molecule, which is attached to one or more phosphate groups. The nitrogenous bases are organic molecules and are so named because they contain carbon and nitrogen.

They are bases because they contain an amino group that has the potential of binding an extra hydrogen, and thus, decreasing the hydrogen ion concentration in its environment, making it more basic. Adenine and guanine are classified as purines. The primary structure of a purine consists of two carbon-nitrogen rings.

Cytosine, thymine, and uracil are classified as pyrimidines which have a single carbon-nitrogen ring as their primary structure. What is a nucleic acid? What elements are nucleic acids made of? What are the monomers that make the building blocks of nucleic acids? What are the three components of a nucleotide? List the types of nucleic acids described in the module 6.

What are the functions of nucleic acid listed in the module? Nucleotides are the monomers that make up the nucleic acid polymers. Adenosine triphosphate ATP is a nucleotide that has an important function by itself. ATP is a direct and rapid energy source for most cellular activities. ATP consists of a single adenosine the nitrogen-containing base adenine and the sugar ribose , linked to three phosphate ions. When an enzymatic reaction breaks them down, a large amount of energy is released.

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. DNA is the genetic material found in all living organisms and is found in the nucleus of eukaryotes and in the chloroplasts and mitochondria.

In prokaryotes, the DNA is not enclosed in a membranous envelope. Each nucleotide is made up of three components: a nitrogenous base, a pentose five-carbon sugar called ribose, and a phosphate group. RNA Structure : A nucleotide is made up of three components: a nitrogenous base, a pentose sugar, and one or more phosphate groups.

Adenine A , guanine G , and cytosine C are present, but instead of thymine T , a pyrimidine called uracil U pairs with adenine. The DNA molecules never leave the nucleus but instead use an intermediary to communicate with the rest of the cell. This is called transcription.

The mRNA then carries the code out of the nucleus to organelles called ribosomes for the assembly of proteins. Once the mRNA has reached the ribosomes, they do not read the instructions directly. It then reads the sequence in sets of three bases called codons. Each possible three letter arrangement of A,C,U,G e. The ribosome acts like a giant clamp, holding all of the players in position, and facilitating both the pairing of bases between the messenger and transfer RNAs, and the chemical bonding between the amino acids.

These subunits do not carry instructions for making a specific proteins i.



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