CHAPTER 6: GENETIC CONTROL
Protein synthesis results in the creation of a protein molecule under the control of DNA. Without DNA, protein synthesis cannot occur. In the vocabulary quiz I answered what transcription and translation are correctly, but I did not answer how a protein molecule is formed correctly in the test. However, below I have corrected the mistake I made in the test.
Stages of Protein Synthesis:
1) Transcription: In the nucleus a complementary copy of the code from a gene is made by building a molecule of mRNA, using one strand of DNA as a template. The process copies the DNA code onto an mRNA molecule.
2) Translation: DNA code is translated into an amino acid sequence. The mRNA leaves the nucleus and attaches to a ribosome in the cytoplasm. In the cytoplasm there are molecules of tRNA which have a particular triplet of bases (anticodon) at one end and able to attach to a specific amino acid at the other.
The tRNA pick up their specific amino acids on the cytoplasm and bring them to the mRNA on the ribosome. The anticodon on the tRNA links up with the codon on the mRNA molecule. Two amino acids are then joined by a peptide bond on the the ribosome at any given time. The base sequence on the DNA molecule determines the base sequence on the mRNA, which determine which tRNA molecules can link up with them. This process continues and the tRNA leaves the ribosome mRNA complex. The chain continues to grow until a stop codon is exposed on the ribosome.
This process of control of protein synthesis by DNA is important because it creates proteins. Proteins play structural, hormonal, and energy roles in cells. Therefore, they are vital to the day to day functions of cells and the control by DNA is necessary.
Stages of Protein Synthesis:
1) Transcription: In the nucleus a complementary copy of the code from a gene is made by building a molecule of mRNA, using one strand of DNA as a template. The process copies the DNA code onto an mRNA molecule.
2) Translation: DNA code is translated into an amino acid sequence. The mRNA leaves the nucleus and attaches to a ribosome in the cytoplasm. In the cytoplasm there are molecules of tRNA which have a particular triplet of bases (anticodon) at one end and able to attach to a specific amino acid at the other.
The tRNA pick up their specific amino acids on the cytoplasm and bring them to the mRNA on the ribosome. The anticodon on the tRNA links up with the codon on the mRNA molecule. Two amino acids are then joined by a peptide bond on the the ribosome at any given time. The base sequence on the DNA molecule determines the base sequence on the mRNA, which determine which tRNA molecules can link up with them. This process continues and the tRNA leaves the ribosome mRNA complex. The chain continues to grow until a stop codon is exposed on the ribosome.
This process of control of protein synthesis by DNA is important because it creates proteins. Proteins play structural, hormonal, and energy roles in cells. Therefore, they are vital to the day to day functions of cells and the control by DNA is necessary.