Are you studying nucleic acids? These biological molecules play a key role in everything from protein synthesis to data storage, but they can be confusing. That’s why we’ve assembled the most commonly asked questions about nucleic acids, so you can learn all about these important compounds (and ace your exam).
What are the two types of nucleic acids?
The next question you may have is what are the two types of nucleic acids?
The answer to this question is DNA and RNA. Nucleotides are their building blocks and they contain a sugar, phosphate, and one of four nitrogenous bases: adenine, thymine (or uracil), cytosine and guanine.
DNA stands for ‘deoxyribonucleic acid’ while RNA stands for ‘ribonucleic acid’. The difference between them is that DNA is double stranded while RNA is single stranded.
What is a nucleotide?
Nucleotides are the building blocks of DNA and RNA. They’re made up of a sugar molecule, a phosphate group, and one of five nitrogenous bases: adenine (A), thymine (T), guanine (G), cytosine (C), or uracil (U). DNA uses the nucleotide pairs AT or GC in its double helix structure; RNA uses only A-T and U-G pairs.
How does DNA store genetic information?
DNA is a double helix.
The reason it takes the shape of a twisted ladder is because of hydrogen bonds between bases. The two strands of DNA are held together by hydrogen bonds, which are weak chemical bonds that occur between one oxygen atom and two hydrogen atoms (one from each strand).
In order to change its shape, the base must break these bonds.
What does a codon do in protein synthesis?
A codon is a triplet of nucleotides that encode the amino acids in a protein. Each codon represents a specific amino acid, with the exception of three stop codons that signal the end of a messenger RNA (mRNA) molecule. There are 64 possible combinations (43) of four different nucleotides and they are read from the start site to the stop site on an mRNA molecule in order to create proteins.
What is the function of DNA and RNA?
Nucleic acid is the blueprint for life. DNA, or deoxyribonucleic acid, is one of two types of nucleic acids; RNA, or ribonucleic acid, being the other. These molecules are made up of an identical set of subunits called nucleotides (a more common name for which is “bases”).
Each nucleotide consists of a phosphate group attached to a nitrogenous base and a pentose sugar molecule joined by ester bonds between C1′ and C3′, with the exception of pyrimidines which have an extra oxygen atom at C2′.
DNA differs from RNA in that it has thymine instead of uracil as its base at position 3 (whereas in RNA uracil does not appear). The sugars in all three types are ribose (except for deoxyribose in DNA), whereas their phosphate groups differ: adenine’s contains 4 oxygen atoms while cytosine has 2; guanine contains 3 while thymine has 5; adenine’s carbonyl group forms a hydrogen bond with the N-7 proton on thymine whereas guanine only bonds through van der Waals forces due to its larger size.
Nucleic Acids are Super Important!
Perhaps you’ve heard of DNA and RNA before, but you may not know how important they are. They’re so important that we’ll spend a whole section learning about them!
DNA is a nucleic acid that contains the genetic information for an organism. It is made up of four kinds of nucleotides: adenine (A), cytosine (C), guanine (G) and thymine (T). Each nucleotide is made up of a sugar molecule called deoxyribose, a phosphate group and one of either A or T.
Because DNA molecules have two strands linked together by hydrogen bonds between A in one strand and T in another strand, it’s called “double-stranded” DNA. RNA stands for ribonucleic acid—the other type of nucleic acid found in cells! Like DNA, RNA also contains four different types of nucleotides: adenine (A), cytosine (C), guanine (G) and uracil (U). Unlike DNA however…
Nucleic acids are the backbone of all organisms and each organism has a unique DNA sequence. There are many genes in our genome that can affect health, behavior, and disease state. If you have questions about your own genetic information or want to know how it’s being used by researchers around the world, check out some of our resources below!
- Alberts, B. et al. Molecular biology of the cell. (2002). https://www.ncbi.nlm.nih.gov/books/NBK26821/
- Bergman, J. ATP: the perfect energy currency for the cell. (2002). https://www.trueorigin.org/atp.php
- BYJU (n.d.). https://byjus.com/biology/structure-of-rna/
- MEDSimplified. (2017). https://www.youtube.com/watch?v=0lZRAShqft0