* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download DNA and Proteins
Molecular cloning wikipedia , lookup
Eukaryotic transcription wikipedia , lookup
RNA polymerase II holoenzyme wikipedia , lookup
Cell-penetrating peptide wikipedia , lookup
Protein (nutrient) wikipedia , lookup
Polyadenylation wikipedia , lookup
Protein moonlighting wikipedia , lookup
Non-coding DNA wikipedia , lookup
Bottromycin wikipedia , lookup
Western blot wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Molecular evolution wikipedia , lookup
Transcriptional regulation wikipedia , lookup
Protein adsorption wikipedia , lookup
Intrinsically disordered proteins wikipedia , lookup
List of types of proteins wikipedia , lookup
Protein structure prediction wikipedia , lookup
Non-coding RNA wikipedia , lookup
Two-hybrid screening wikipedia , lookup
Amino acid synthesis wikipedia , lookup
Silencer (genetics) wikipedia , lookup
Messenger RNA wikipedia , lookup
Point mutation wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Gene expression wikipedia , lookup
Proteolysis wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Biochemistry wikipedia , lookup
Epitranscriptome wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
DNA and Protein Synthesis Notes We have already referred to DNA as a code or blueprint for living things. More specifically it is a code for making Proteins. The Hypothesis, “1 Gene= 1 Polypeptide” illustrates the fact that every gene located on a chromosome “codes” for 1 polypeptide or protein. If polypeptides are strings of proteins and proteins are strings of amino acids, then DNA determines the sequence (or order) of the amino acids. Protein Synthesis – Simply the manufacturing of proteins. We know that the assembly of proteins occurs in the Ribosomes, but if the blueprint for proteins is inside the nucleus on DNA, then how do the ribosomes know what to do? The actual transfer and assembly of proteins is carried out by the nucleic acid RNA. RNA (Ribonucleic Acid) is similar to DNA but instead of being double stranded, it is only single stranded. It consists of a Pentose sugar (ribose), a Phosphate, and a Nitrogenous Base. The bases offer one of the biggest differences. Purines are the same with RNA = Adenine and Guanine Pyrimidines are different – Uracil(instead of thymine) and cytosine. A binds with T C binds with G The process of protein synthesis: mRNA (messenger RNA) carries the instructions from the DNA to the ribosomes. tRNA ( transfer RNA) transports the amino acids to ribosomes in their correct order. rRNA ( ribosomalRNA) helps to make up the structure of the ribosome. The process of transferring information from DNA to mRNA is called Transcription. During the process of transcription, the following happens: 1. A particular portion of a DNA strand begins to unwind. 2. The enzyme RNA Polymerase begins to match up base pairs. mRNA A binds with T U binds with A G binds with C C binds with G Exposed parent strand of DNA G U A G A T C 3. 4. 5. 6. These new pairs begin to form a strand of mRNA. The mRNA leaves the nucleus through the Nuclear Pore The original DNA winds back up. The mRNA goes to a ribosome and binds to it. (the organelle that actually synthesizes the protein) 7. The codons on the mRNA bind with Anti-codon found on tRNA. 8. tRNA then goes and finds the corresponding Amino Acid and brings them to the ribosome to be synthesized into protein. 9. The process of converting codons into anticodons and then amino acids is called Translation. More specifically, the mRNA creates codes for the proteins from DNA. These codes occur in sequences of 3 . For example, 3 U’s in a row codes as UUU and equals the amino acid Penylalanine. The letter code is called a Codon. With the letters available – U, A, G, and C; there are 64 possible combinations. There are only 20 amino acids that occur in nature. This means that some amino acids may have more than 1 code. AUG = the amino acid Methionine = the universal start codon. This tells a ribosome when to start making proteins. There are also STOP Codons that instruct a ribosome to stop protein synthesis. These include: UGA, UAA & UAG The corresponding letters on the tRNA are called Anti-codons.