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What’s the central dogma of biology?

What’s the central dogma of biology?. DNA  RNA  Protein DNA  Protein  Gene DNA  Keratin  Hair DNA  RNA  Amino Acid. DNA  RNA  Protein !. What’s the 1 st step of protein synthesis?. Protein Transcription Translation DNA. Transcription!.

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What’s the central dogma of biology?

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  1. What’s the central dogma of biology? • DNA  RNA  Protein • DNA  Protein  Gene • DNA  Keratin  Hair • DNA  RNA  Amino Acid DNA  RNA  Protein!

  2. What’s the 1st step of protein synthesis? • Protein • Transcription • Translation • DNA Transcription!

  3. Where does transcription take place in the cell? • Cytoplasm • Ribosome • Nucleus • Cell Membrane Nucleus!

  4. What’s the complementary mRNA molecule to this gene??3’-TAGTTAAAGCCC-5’ 5’-AUCAAUUUCGGG-3’

  5. Where we left off… • We’ve completed the 1st step of protein synthesis (transcription)… now what? TRANSLATION! • So far, we have an mRNA molecule that we’ve made from the DNA. • The mRNA has left the nucleus & is headed to the cytoplasm!

  6. Protein Synthesis - Translation

  7. Translation • The mRNA made during transcription is used to make a protein. • DNA  mRNA  Protein

  8. Remember! • Proteins (sometimes called polypeptides) are macromolecules made of monomers called amino acids!

  9. Translation – Step 1 • The mRNA molecule (made during transcription) attaches to a ribosome in the cytoplasm.

  10. Translation – Step 2 • The mRNA is broken down into sets of 3 nucleotides, or codons. • The nucleotides are read in “words” made of 3 nucleotide “letters”. • Each “word” is called a codon & contains the genetic code for 1 amino acid.

  11. What type of RNA is attached to amino acids? • mRNA • rRNA • tRNA • All of the above tRNA!

  12. Translation – Step 3 • As each codon of the mRNA moves through the ribosome, the correct amino acid is brought to the ribosome by tRNA.

  13. Each tRNA molecule has a group of 3 nucleotides called the anticodon & an amino acid attached. • The anticodons pair with the codons! The first “word”, or start codon, is always the same for every protein! It is always AUG!

  14. Methionine! Using the genetic code wheel, you can figure out which amino acid a codon represents. Which amino acid is associated with the start codon AUG? Move from the inside out!

  15. There are a total of 20 different amino acids that can be arranged in different ways to make different proteins!

  16. Translation – Step 4 • The ribosome transfers the amino acid from the tRNA to the polypeptide chain being formed in a process called elongation. • This makes the polypeptide chain longer & longer! • This forms a peptide bond between the amino acids, which is why proteins are called polypeptides!

  17. Translation – Step 5 • The empty tRNA molecule exits the ribosome & is recycled by the cell & can bind another amino acid.

  18. Translation – Step 6 • The ribosome continues to match codons in the mRNA with anticodons in tRNA until it reads a codon that says “stop.” When this happens, the ribosome releases the mRNA & the protein.

  19. Why are proteins important?

  20. Each protein has a specific function within living cells! • Can be enzymes, to speed up & regulate chemical reactions • Making pigments that determine flower color in plants • Determine your blood type • Regulate cell growth & development

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