1. Transcription and Translation Chapter 21

2. Objectives Summarize how genetic information is encoded in DNA, how it provides instructions for making proteins.

3. RNA Ribonucleic acid Has Ribose It is the messenger for DNA to be made into amino acids for proteins. Compare DNA to the master copy. RNA is the worker who takes a copy from the Forman and goes to make a house using the plans.

4. Differences between RNA & DNA RNA has Ribose Single stranded Uracil instead of Thymine Messenger for DNA The working copy In Eukaryotes it exits the nucleus DNA has Deoxyribose Double stranded Thymine instead of Uracil Blueprint for Proteins The master copy In Eukaryotes, stays in nucleus

6. Types of RNA Messenger RNA- mRNA- is the copy of a gene from DNA Transfer RNA- tRNA- transfers amino acids onto a triplet code of bases. Ribosomal RNA- rRNA- helps make proteins from the RNA. It’s a round ribosome in the cytoplasm.

7. Transcription RNA polymerase opens DNA. Complementary bases pair up, except A-U. RNA polymerase joins the nucleotides together. RNA strand is made from a section of DNA in the nucleus. Small parts of noncoding RNA are taken out in the nucleus: called Introns. They don’t code for proteins. Exons are allowed to exit the nucleus and go make proteins. One end of the RNA is capped by an altered guanine. The other end of RNA is capped by an altered adenosine

8. Small RNA molecules Regulate mRNA processing Regulate transcription Regulate translation These are called ribozymes.

9. Transcription https://www.youtube.com/watch?v=5MfSYnItYvg

10. Translation Making proteins out of RNA. Codon- 3 bases on mRNA Anticodon – 3 bases on tRNA

11. Genetic code has 3 base codons Each codon represents one of 20 amino acids. There are 64 possible codons for all 20 amino acids There are start codons and stop codons Start codon is AUG in humans, which makes methionine. Stop codons are UAA, UGA, and UAG, which don’t make amino acids.

12. Amino acids

13. Genetic code chart

14. Proteins Are made of small subunits called amino acids, which make polypeptides. There are 20 amino acids. Proteins have a certain shape and polarity or non-polarity, which determines their function. Some proteins bind with water, while others don’t. Proteins have thousands of amino acids in different order. Structure Regulation enzymes Antibodies in the immune system Hormones that regulate cell function

15. Steps of Translation Initiation- mRNA binds to a small section of ribosome. The larger section attaches forming a translation complex.

16. Translation

17. Translation Elongation Polypeptide lengthens one amino acid at a time, about 5 per second. tRNA arrives at site A in the ribosome, which receives the amino acid and the mRNA moves laterally one codon at a time to the P site.

18. Translation Termination Stop codons (UGA, UAA, UAG) are reached in the A site. Ribosome separates into two subunits and falls off the mRNA. https://www.youtube.com/watch?v=5bLEDd-PSTQ https://www.youtube.com/watch?v=VJycRYBNtwY

19. Biology Central Dogma