How Proteins Are Made CHAPTER 10. DNA, genes, chromosomes. How does a chemical control so much?. DNA. Deoxyribo Nucleic Acid. Sugar: deoxy ribose Phosphate: H 2 PO 4. Nitrogen base: Adenine Guanine Thymine Cytosine. Answers
How does a chemical control so much?
1. Proteins are chains of linked amino acids that have been folded into compact shapes. Some proteins play important roles as enzymes. Other proteins are structural components of cells and tissues.
2. Ribosomes are structures built of proteins and RNA that serve as assembly sites for protein synthesis.
3. DNA is an extremely long, linear molecule containing many genes; genes are relatively short segments of DNA that code for protein or RNA.
4. DNA is made of two strands of complementary nucleotides and contains the four bases adenine, thymine, cytosine, and guanine. DNA contains the sugar deoxyribose and serves to store the complete set of an organism’s genetic material.
5. In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C).
3. chromosomal mutation
5. double helix
6. frameshift mutation
7. messenger RNA mRNA
10. nitrogen base
12. point mutation
14. ribosomal RNA rRNA
16. transfer RNA tRNA
The instructions for building a protein are found in a gene and are “rewritten”to a molecule of RNA during transcription. The RNA is then “deciphered” during translation
The RNA is complementary to the gene, and the RNA nucleotides are put together with the help of RNA polymerase.
Prokaryotic and eukaryotic cells are able to control which genes are expressed and which are not, depending on the cell’s needs.
In prokaryotes, gene expression is regulated by operons.
Gene expression is switched off when repressor proteins block RNA polymerase from transcribing a gene.
Lac operon: the operon that controls the production of lactose metabolism enzymes.
Repressors are proteins that bind to the operon and physically block RNA polymerase from producing mRNA
The segments of DNA that are expressed are called exons.
After transcription, the introns are cut out, and the exons are joined. The exons are then translated.
1. Starts in the nucleus with the DNA gene.
2. DNA to RNA is called transcription
3. RNA polymerase is the enzyme that unzips and transcribes DNA to RNA.
4. Complimentary bases A-U, T-A, C-G, G-C ( no Thymine in RNA)
5. mRNA goes out of nucleus to the cytoplasm to find a ribosome.
6. Ribosome matches mRNA to tRNA
7. mRNA has the codon
8. codon is a set of 3 nitrogen bases that codes for an amino acid.
9. tRNA has the anti codon on one end
10. tRNA has the amino acid on the other end
11. ribosome has an A and a P site
12. amino acids bond together with peptide bonds to form proteins
13. The part of the process that occurs on the ribosome is called translation