Nucleic Acid
The nucleic acids are the building blocks of living organisms. You may have heard of DNA described the same way. Guess what? DNA is just one type of nucleic acid. Some other types are RNA, mRNA, and tRNA. All of these "NAs" work together to help cells replicate and build proteins. NA? Hold on. Might that stand for nucleic acid? It might. Nucleic Acid are molecules that store and transfer heredity and gentic information. They are composed of Hydrogen, Oxegen, Nitrogen, and Carbon. There are two basic types of Nucleic Acid. They are DNA and RNA. DNA and RNA are molecules that consist of many nucleotides linked together to form a long chain. Nucleic acid is found in all living cells and is located in the nucleus of cells. I already told you about the biggie nucleic acids. They are actually made up of chains of base pairs of nucleic acids stretching from as few as three to millions. When those pairs combine in super long chains,DNA, they make a shape called a double helix. The double helix shape is like a twisty ladder. The base pairs are the rungs. Everything you are in your body is encoded in the DNA found in your cells. Scientists still debate how much of your personality is even controlled by DNA.
DNA
- DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus.The information in DNA is stored as a code made up of four chemical bases: adenine, guanine, cytosine, and thymine.
- Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.
- Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.
- An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.
RNA
- Ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information.
- RNA is a biologically important type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nitrogenous base, a ribose sugar, and a phosphate.
- RNA is very similar to DNA, but differs in a few important structural details: in the cell, RNA is usually single-stranded, while DNA is usually double-stranded; RNA nucleotides contain ribose while DNA contains deoxyribose; and RNA has the base uracil rather than thymine that is present in DNA.