Presentation on theme: "1 Review How does a cell interpret the genetic code Explain What are codons and anticodons 2 Review What happens during translation Compare and Contrast."— Presentation transcript:
11 Review How does a cell interpret the genetic code Explain What are codons and anticodons 2 Review What happens during translation Compare and Contrast How is protein synthesis different from DNA replication 3 Review Why is the genetic code considered universal Infer In what way does controlling the proteins in an organism control it’s characteristics 4 Choose one component of translation. Write a question about that component and use it to form a hypothesis that could be tested in an experiment
2Ch 13 RNA and Protein Synthesis 13.2 Ribosomes and Protein Synthesis
3Proteins are made from long chains of amino acids or polypeptides 20 different amino acidsOrder of amino acids make proteins different.
4Codon Each three-letter “word” in mRNA Consists of three consecutive bases that specify a single amino acid.
5How to Read CodonsFour different bases in RNA, so 64 possible three- base codons (4×4×4 = 64)To read a codon, start at the middle of the circle and move outward.
8Translation Decoding of an mRNA message into a protein From RNA to proteinDifferent languages.
9Translation StepsmRNA is transcribed in the nucleus and then enters the cytoplasm for translation.
10Ribosome attaches to an mRNA molecule Ribosome reads each codon of mRNADirects tRNA to bring the specified amino acidRibosome then attaches each amino acid to the growing chain.
11tRNA has three unpaired bases or anticodon which is complementary to one mRNA codon Codon AUGAnticodon UAC.
12Next codon is UUCtRNA molecule with an AAG anticodon brings the amino acid to ribosome.
13Ribosome helps form a peptide bond between 1st and 2nd amino acid Bond between tRNA molecule and amino acid is brokentRNA shifts to 3rd site.
14Ribosome moves over one codon New tRNA enters ribosomeProcess repeats itself.
15Translation continues until a stop codon Ribosome release polypeptide and mRNA.
16Molecular Basis of Heredity Most genes contain instructions for assembling proteins.
17Proteins Can Be enzymes Produce pigment or odor Regulate growth Trigger developmentOperate cell parts.
18Gene Expression What DNA actually ends up doing How the genes gets expressed or shown.
19Genetic code is nearly universal in all living organisms.
20A certain gene has the following base sequence GACAAGTCCACAATC Write this sequence downFrom left to right, write the sequence of mRNA molecule transcribed from this geneUsing the figure on pg. 311, read the mRNA from left to right and write down the amino acid sequenceRepeat step 3 reading the codons from right to left.
21Analyze and ConcludeApply Concepts Why did steps 3 and 4 produce different polypeptidesInfer Do cells usually decode nucleotides in one direction only or in either direction