Question

Starting with the DNA strand, describe the full process of how to form a protein. In your writing: describe and discuss the differences between DNA and RNA and discuss the concept “central dogma of life. Be sure to describe the 4 levels of protein structure and the environmental factors that are important (assuming that this is a human protein). What would happen if the DNA had a single nucleotide mutation? ( I want a detailed answer please)

Answer 1

Answer - The central dogma of molecular biology explains the flow of genetic information, from DNA to RNA to make a functional product, a protein. The central dogma illustrate that DNA contains the information needed to make all of our proteins, and that RNA(mRNA) is a messenger that carries this information to the ribosomes. The ribosomes serve as factories in the cell where the information is ‘translated’ from a code into the functional product.The process by which the DNA instructions are converted into the functional product is called gene expression. Gene expression has two key steps - transcription and translation. In the transcription, the information in the DNA of every cell is converted into small mRNA messages.During translation, these messages travel from where the DNA is in the cell nucleus to the ribosomes where they are ‘read’ to make specific proteins.The central dogma states that the pattern of information that occurs most frequently in our cells is to make a new copy of DNA from the existing DNA. From DNA to make new mRNA is called as transcription. From mRNA to make new proteins translation.

Proteins -  

The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis. The two ends of the polypeptide chain are referred to as the carboxyl terminus (C-terminus) and the amino terminus (N-terminus) based on the nature of the free group on each extremity. The primary structure of a protein is determined by the gene corresponding to the protein. A specifics sequence of nucleotides in DNA is transcribed into mRNA, which is read by the ribosome in a process called translation.

Secondary structure refers to highly regular local sub-structures on the actual polypeptide backbone chain. Two main types of secondary structure, the α-helix and the beta - helix. These secondary structures are defined by patterns of hydrogen bonds between the main-chain peptide groups. They have a regular geometry. Both the α-helix and the β-sheet represent a way of saturating all the hydrogen bond donors and acceptors in the peptide backbone. Some parts of the protein are ordered but do not form any regular structures.

Tertiary structure refers to the three-dimensional structure of monomeric and multimeric protein molecules. The α-helixes and β-pleated-sheets are folded into a compact globular structure. The folding is driven by the non specific  hydrophobic interactions, the burial of hydrophobic residues from water, but the structure is stable only when the parts of a protein domain are locked into place by specific tertiary interactions, such as salt bridges, hydrogen bonds, and the tight packing of side chains and disulfide bonds. The disulfide bonds are extremely rare in cytosolic proteins.

Quaternary structure is the three-dimensional structure consisting of the aggregation of two or more individual polypeptide chains (subunits) that operate as a single functional unit (multimer). The resulting multimer is stabilized by the same non-covalent interactions and disulfide bonds as in tertiary structure. There are many possible quaternary structure organisations.Complexes of two or more polypeptides (i.e. multiple subunits) are called multimers. Specifically it would be called a dimer if it contains two subunits, a trimer if it contains three subunits, a tetramer if it contains four subunits, and a pentamer if it contains five subunits. Multimers made up of identical subunits are referred to with a prefix of "homo-" and those made up of different subunits are referred to with a prefix of "hetero-", for example, a heterotetramer, such as the two alpha and two beta chains of hemoglobin.

A single point mutation  change the whole DNA  sequence. Changing one  purine or pyrimidine can change the amino acid that the nucleotides code for. Point mutations may  arise from spontaneous mutations  that occur during DNA replication. The rate of mutation may  be increased by mutagens.