o r F m D Protein N A to Day 2

Include 3 similarities and 3 differences between the two molecules Compare and contrast the DNA molecule on the left with the RNA molecule on the right Include 3 similarities and 3 differences between the two molecules

The genetic code is used as a blueprint to make proteins.

How does a gene code for a protein? To manufacture proteins, cells follow a very systematic 2 step procedure that first transcribes DNA in the nucleus into mRNA and then translates the mRNA into chains of amino acids in the cells ribosomes. 2

contains a different sugar (ribose instead of deoxyribose) has only a single strand of nucleotides instead of two strands contains the nitrogen base uracil (U) instead of thymine (T) RNA is very similar to DNA except that it:

Three Types of RNA Ribosomal RNA (rRNA), along with protein, makes up the ribosomes Messenger RNA (mRNA) copies DNA’s code & carries the genetic information to the ribosomes Transfer RNA (tRNA) transfers amino acids to the ribosomes where proteins are synthesized

The “m” in “mRNA” stands for “messenger,” because mRNA copies genetic information from DNA (which is found in the nucleus) and carries it to another part of the cell (the ribosomes). A G T C Messinger (mRNA)

Transcription

Transcribe the DNA sequence below into a strand of mRNA G T T C C G A T C ? ? ? ? ? ? ? ? ? mRNA

Where in a cell does the process below take place? A A A G G C T A G T T T C C G A T C U U U C C G A U C

What product is produced as a result of this process? A A A G G C T A G T T T C C G A T C U U U C C G A U C

translating the Genetic Code

Think of the genetic code the mRNA is carrying as a series of three-letter “words.” Each of these three-letter words is called a codon. O.K., we’ve gone from DNA to mRNA. How do proteins fit into all this? Codon

Different codons code for different amino acids Different codons code for different amino acids. For example, the codon for the amino acid methionine is AUG (adenine, uracil, guanine). The codon for the amino acid serine is UCA (uracil, cytosine, adenine).

Another type of RNA, called tRNA (“t” stands for “transfer”) matches the codons in mRNA to the correct amino acids. As the mRNA strand moves along the ribosome, the amino acids are joined in the correct sequence to form a protein. This process is called translation.

Translation aa C C U Proine U C G Serine A C C Tryptophan G G A Codon G U U Valine G Translation

The diagram below shows a codon chart The diagram below shows a codon chart. A codon chart shows which codons code for which amino acids.

This chart shows the amino acids coded for by each of the 64 possible mRNA codons. To find which amino acid the codon CAA codes for, follow these steps. (1) Look on the left side of the chart to find the large row of codons that begin with C. (2) Move across this row until you get to the column of codons whose second base is A. (3) Move down this column until you get to the row of codons whose third base is A. The codon CAA codes for the amino acid glutamine.

Suppose a DNA mutation led to a change in a single mRNA codon Suppose a DNA mutation led to a change in a single mRNA codon. Now suppose this codon changed from GCC to GCG. By looking at the codon chart, you can see that both of these codons code for the amino acid alanine. So even though the DNA and mRNA have changed, there is no change in the protein!

Any change in the DNA would cause a change in the mRNA molecule AUG CCU AUU GAU GGC CCA UAA GUU How would a change in the sequence of nucleotides in a DNA molecule affect the mRNA transcribed from the DNA molecule? Any change in the DNA would cause a change in the mRNA molecule

Methionine (start) Leucine Theronine Stop

Identify the structures labeled I, II, III, IV and V Amino Acid Protein Anticodon Transfer tRNA Messenger mRNA Identify the structures labeled I, II, III, IV and V

Help Wanted Positions Available in the genetics industry. Hundreds of entry-level openings for tireless workers. No previous experience necessary. Must be able to transcribe code in a nuclear environment. The ability to work in close association with ribosomes is a must. Accuracy and Speed vital for this job in the field of translation. Applicants must demonstrate skills in transporting and positioning amino acids. Salary commensurate with experience. Executive Position available. Must be able to maintain genetic continuity through replication and control cellular activity by regulation of enzyme production. Limited number of openings. All benefits. Supervisor of production of proteins—all shifts. Must be able to follow exact directions from double-stranded template. Travel from nucleus to the cytoplasm is additional job benefit. Applicants for the first job, “Positions Available,” could qualify if they were? mRNA

Help Wanted tRNA Applicants for the second job, “Accuracy Positions Available in the genetics industry. Hundreds of entry-level openings for tireless workers. No previous experience necessary. Must be able to transcribe code in a nuclear environment. The ability to work in close association with ribosomes is a must. Accuracy and Speed vital for this job in the field of translation. Applicants must demonstrate skills in transporting and positioning amino acids. Salary commensurate with experience. Executive Position available. Must be able to maintain genetic continuity through replication and control cellular activity by regulation of enzyme production. Limited number of openings. All benefits. Supervisor of production of proteins—all shifts. Must be able to follow exact directions from double-stranded template. Travel from nucleus to the cytoplasm is additional job benefit. Applicants for the second job, “Accuracy and Speed,” could qualify if they were tRNA

Help Wanted Positions Available in the genetics industry. Hundreds of entry-level openings for tireless workers. No previous experience necessary. Must be able to transcribe code in a nuclear environment. The ability to work in close association with ribosomes is a must. Accuracy and Speed vital for this job in the field of translation. Applicants must demonstrate skills in transporting and positioning amino acids. Salary commensurate with experience. Executive Position available. Must be able to maintain genetic continuity through replication and control cellular activity by regulation of enzyme production. Limited number of openings. All benefits. Supervisor of production of proteins—all shifts. Must be able to follow exact directions from double-stranded template. Travel from nucleus to the cytoplasm is additional job benefit. Applications for the third job, “Executive Position,” could qualify if they were DNA

Help Wanted rRNA or Ribosomes Positions Available in the genetics industry. Hundreds of entry-level openings for tireless workers. No previous experience necessary. Must be able to transcribe code in a nuclear environment. The ability to work in close association with ribosomes is a must. Accuracy and Speed vital for this job in the field of translation. Applicants must demonstrate skills in transporting and positioning amino acids. Salary commensurate with experience. Executive Position available. Must be able to maintain genetic continuity through replication and control cellular activity by regulation of enzyme production. Limited number of openings. All benefits. Supervisor of production of proteins—all shifts. Must be able to follow exact directions from double-stranded template. Travel from nucleus to the cytoplasm is additional job benefit. Applicants for the fourth job, “Supervisor,” could qualify if they were rRNA or Ribosomes

Based on the information provided in the table, which plant species is most closely related to the endangered species? Support your answer. LEU GLY SER PRO UAU GGG UCC CCU