Relationship Between DNA Bases Genes, Proteins and Traits | Sciencing
Start studying Biology - Genes/Proteins/DNA. Learn vocabulary, terms The connection between genes and proteins Phenotypes (physical traits). Upgrade to. The DNA from other animals would produce genes and traits in the form of DNA called genes, break off and new nucleotides pair up with the. The terminology can be somewhat confusing. Dysferlin is a protein, and "the dysferlin gene" means "the gene which contains the instructions for producing the .
Archibald Garrod Archibald Garrod was one of the first scientists to propose that genes controlled the function of proteins.
Inhe published his observations regarding patients whose urine turned black. This condition known as alkaptonuria happens when there is a buildup of the chemical homogentisate, which causes the darkening of urine.
In most situations, excess amounts of amino acid phenylalanine are metabolised by the body. This led Garrod to surmise that the enzyme responsible for its breakdown must be defective in these patients. In addition, since the black urine phenotype was passed from generation to generation in a regular pattern, Garrod reasoned that a gene had to be responsible for the production of the defective enzyme. He attributed a defective enzyme to a defective gene, suggesting a direct link between genes and proteins.
The Relationship Between Genes and Proteins Most genes contain the information require to make proteins. Specific three-letter groups of RNA nucleotides code for specific amino acids. The combination TTT, for example, codes for the amino acid phenylalanine.
Genes, Traits, and Proteins
Regulatory regions of the gene also contribute to protein synthesis by determining when the gene will be switched on or off. Sciencing Video Vault Proteins In active genes, genetic information determines which proteins are synthesized and when synthesis is turned on or off.
These proteins fold into complicated three-dimensional structures, somewhat like molecular origami. Because each amino acid has specific chemical characteristics, the sequence of amino acids determine the structure and shape of a protein. The primary transcript also undergoes processing steps in the nucleus in order to become a mature mRNA. It is then exported to the cytosol, where it can associate with a ribosome and direct synthesis of a polypeptide in the process of translation.
Transcription takes place in the cytosol.
Uncovering the Relationship Between Genes and Proteins - ATA Scientific
Because of this, the mRNA doesn't have to travel anywhere before it can be translated by a ribosome. In fact, a ribosome may begin translating a mRNA before it is even fully transcribed while transcription is still going on.
The location of transcription is also different between prokaryotes and eukaryotes. Eukaryotic transcription takes place in the nucleus, where the DNA is stored, while protein synthesis takes place in the cytosol. Because of this, a eukaryotic mRNA must be exported from the nucleus before it can be translated into a polypeptide.
Prokaryotic cells, on the other hand, don't have a nucleus, so they carry out both transcription and translation in the cytosol.
Translation After transcription and, in eukaryotes, after processingan mRNA molecule is ready to direct protein synthesis. The process of using information in an mRNA to build a polypeptide is called translation.
The genetic code During translation, the nucleotide sequence of an mRNA is translated into the amino acid sequence of a polypeptide.
Intro to gene expression (central dogma)
Specifically, the nucleotides of the mRNA are read in triplets groups of three called codons. There are 6 1 61 61 codons that specify amino acids. One codon is a "start" codon that indicates where to start translation. The start codon specifies the amino acid methionine, so most polypeptides begin with this amino acid.
These relationships between codons and amino acids are called the genetic code.