in cystic fibrosis, how does a small change in the DNA of a single gene affect a protien?

Answer 1

This is going to be a quick answer but I hope it helps.

DNA is the blueprint to make protiens. Protiens are made up of amino acids. there are 4 different nucleotids A,T,C,G that can code for an amino acid. Each amino acid is coded in DNA by three nucleotides. Thus, 4 nucleotides raised to the third gives 64 possible sequences. There are twenty amino acids coded for thus there is overlap but even changing just one of the nucleotides can change the amino acid produced. This change in the amino acid changes the protien that is eventually made from the amino acid chain, it can be a small change that has little effect, no change (since there is overlap) or it can be a big change that has detrimental effects.

I hope that helps it need clarification I will try to give it.

Answer 2

Cystic fibrosis is an inherited disease process with chages to the CFTR gene. This gene makes a protein that act as a channel for chloide ions to pass through the cell membrane.

The DNA is translated to RNA, and the RNA is then transcribed into a protein. As the protein is built, RNA is "read" in groups of 3 base pairs (called a codon) to determine which amino acid should be added next. A change of even just one base pair could change which amino acid is inserted. This change can alter the final shape of and functionality of the protein (the altered protein may still haev some functionality) .

Other small changes could be more drastic. As the protein is being bulit, the process continues until a stop codon is reached. A small mutation could result in a new stop codon and the cell machinery prematurely stopping protein synthesis. This results in a final product which is only a fragment of the intended product. It may result in absolutely no functional protien being produced.

Finally, the most common mutation to the CFTR gene is a 3 base pair (single codon) deletion. This results in a finished product that is lacking a single amino acid (phenylalanine at the 508th position is most common) and the protein is misshapen and less functional than normal.

Answer 3

Because a single gene serves a transcription unit template for a protein
Remeber The central dogma DNA->RNA->Protein

During Transcription, DNA in our chromosomes transcribes messenger RNA in the cell nucleus

During Translation, in the cytoplasm, the messenger RNA is translated to create a protein polypeptide

In Cystic Fibrosis Because the DNA is mutated the proteins that are created cause the lungs to fill with mucus

Answer 4

Cystic fibrosis is caused by a defect in a gene called the cystic fibrosis transmembrane conductance regulator gene. This gene makes a protein that controls the movement of salt and water in and out of the cells in your body. In people with Cystic fibrosis, the gene does not work effectively. This causes the thick, sticky mucus and very salty sweat that are the main features of Cystic fibrosis.

Answer 5

A specific gene is the instructions for a single protein. A protein is actually a specific set of amino acids folded in a particular way. Think of a piece of origami, one wrong fold and the result is completely different, how different is determined by were exactly the wrong fold was (different means it is unlikely to be able to do what it was originally intended for). Also, if you chop half of the protein or origami paper off (early stop codon caused by a single base change in the DNA), there is no way to get something like the original out of the result.