1 Protein Synthesis DNA makes RNA makes Protein hhhh tttt tttt pppp :::: //// //// wwww wwww wwww.... yyyy oooo uuuu tttt uuuu bbbb eeee.... cccc oooo mmmm //// wwww aaaa tttt cccc hhhh ???? vvvv ==== dddd 1111 UUUU PPPP ffff 7777 llll XXXX eeee OOOO 8888

2 RNA RiboNucleic Acid

3 RNA

4 RNA is the same as DNA except: RNA is a nucleic acid the same as DNA except: RNA Sugar is Ribose Not Deoxyribose DNA missing oxygen RNA has oxygen

5 RNA uses Uracil instead of Thymine No Thymine T-A No Thymine T-A Uracil pairs with Adenine: U-A Uracil pairs with Adenine: U-A A-U A-U

6 RNA is a single strand RNADNA

7 There are 3 types of RNA Messenger RNA (mRNA)- Messenger RNA (mRNA)- A copy of the DNA brought to cell Transfer RNA (tRNA) – Transfer RNA (tRNA) – Brings amino acids to the ribosome Ribosomal RNA (rRNA) – Ribosomal RNA (rRNA) – Forms ribosomes

8 Central Dogma DNA makes RNA which makes PROTEIN DNA makes RNA which makes PROTEIN All life depends on this process All life depends on this process

9 What is Protein? Proteins are what form all structures of the body and all life Proteins are what form all structures of the body and all life Muscles Muscles Skin Skin Hair color Hair color Cell structures Cell structures

10 Enzymes are also proteins Proteins are needed in all metabolic functions Proteins are needed in all metabolic functions Enzymes are even needed in the process of making other proteins Enzymes are even needed in the process of making other proteins

11 Steps to make a protein 1 st – Transcription – An mRNA copy of DNA is made in the Nucleus 2 nd – Translation – A ribosome reads the mRNA and assembles the protein

12 Retrovirus Works OPPOSITE central dogma. Works OPPOSITE central dogma. Virus RNA changed to DNA and then placed in host DNA so Host will produce more virus’ Virus RNA changed to DNA and then placed in host DNA so Host will produce more virus’ AIDS is a retrovirus AIDS is a retrovirus

13 Transcription - Occurs in the Nucleus 1) DNA opens up in one section 2) Using enzymes, a complimentary mRNA copy is made from only one side of the DNA called the Coding strand (template strand not used) 3) Pairing A-U C-G  Note: all types of RNA are made in nucleus

14 Transcription Bubble DNA opens up where gene is located DNA opens up where gene is located

15 Transcription steps DNA to RNA 1) Initiation 1) Initiation – RNA Polymerase binds to a promoter – RNA Polymerase binds to a promoter - It reads the template strand 3’ to 5’ - It reads the template strand 3’ to 5’ Eukaryotes need extra proteins to bind to promoter prokaryotes bind directly Eukaryotes need extra proteins to bind to promoter prokaryotes bind directly

16 2 - Elongation RNA polymerase moves down the transcription unit making mRNA in the 5’  3’ direction RNA polymerase moves down the transcription unit making mRNA in the 5’  3’ direction

17 3 - Termination Polymerase moves down to the terminator sequences Polymerase moves down to the terminator sequences

18 3 - Termination After terminator sequences RNA polymerase and the mRNA are removed from the DNA After terminator sequences RNA polymerase and the mRNA are removed from the DNA

19 TATA box – Beginning of the promoter The The

20 TA TA for now

21 Eukaryotic Transcription factors Recognizes the TATA box Recognizes the TATA box Hold the RNA polymerase to the DNA Hold the RNA polymerase to the DNA Made of 6 proteins Made of 6 proteins

22 RNA processing Eukaryotic cells modify the mRNA while it is still in the nucleus Eukaryotic cells modify the mRNA while it is still in the nucleus After processing mRNA leaves nucleus After processing mRNA leaves nucleus

23 1)Addition of a 5’ cap Stabilizes mRNA Stabilizes mRNA Point of attachment for ribosome Point of attachment for ribosome

24 2) Addition of a poly A tail -A-A-A-…..-A-A-A-A-3’ About 200 Adenines stabilizes RNA and helps mRNA cross nuclear membrane About 200 Adenines stabilizes RNA and helps mRNA cross nuclear membrane

25 3) RNA splicing SnRNPs (small nuclear ribonucleoproteins) Bind to pre-mRNA and form a large spliceosome. They remove the introns SnRNPs (small nuclear ribonucleoproteins) Bind to pre-mRNA and form a large spliceosome. They remove the introns

26 Introns vs. Exons Introns need to be removed Introns need to be removed Exons are expressed Exons are expressed

27 4) Alternate RNA slicing A gene may produce 2 or more polypeptides, depending on which segments are considered Exons

28 Translation The building of the protein from mRNA code The building of the protein from mRNA code

29 Ribosomes Are made of rRNA and protein They read the mRNA 2 parts clamp down on mRNA Ribosomes find the proper tRNA with matching amino acid

30 3 LETTER CODE Each amino acid has a 3 letter code DNA has a 3 letter code it transfers to mRNA Codon – The code on mRNA Anticodon – The code on tRNA that matches opposite to the codon tRNA – A clover leaf structure That carries an amino acid to the ribosome

31 Example of base pairing DNA code = mRNA: Codon = tRNA: Anticodon = Note: U substitutes for T in all RNA T C A A G U U C A

32 To Begin Translation Proteins help ribosome find the Start codon Proteins help ribosome find the Start codon AUG = start codon AUG = start codon

33 Each codon is read by ribosome one at a time As each codon is read, one amino acid is brought by tRNA As each codon is read, one amino acid is brought by tRNA

34 Stop Codon Ends the protein Ends the protein There are 3 stop codes There are 3 stop codes

35 In Prokaryotes Transcription is coupled with translation Transcription is coupled with translation

36 Translation

37 Types of ribosomes Free floating ribosomes – make proteins used in the cell, Free floating ribosomes – make proteins used in the cell, - released in cytoplasm ER attached ribosomes – Make proteins for export or use in plasma membrane. ER attached ribosomes – Make proteins for export or use in plasma membrane. -transported and packaged by Membrane system

38 Protein synthsis animation 3 minute youtube lesson 3 minute youtube lesson 3 minute youtube lesson 3 minute youtube lesson

39 Protein synthesis picture mRNA tRNA Ribosome Protein

40 Every part of your body is made of protein. REMEMBER !!!!! DNA makes RNA makes Protein DNA makes RNA makes Protein Now we will see how this works, step by step Now we will see how this works, step by step Animation Protein synthesis 3D animation Animation Protein synthesis 3D animationProtein synthesis 3D animationProtein synthesis 3D animation – 3 mins

41 Mutations Changes in the genetic material of a cell Changes in the genetic material of a cell Thought to be the driving force of evolution Thought to be the driving force of evolution

42 1) Point Mutations Chemical changes to just one base pair Chemical changes to just one base pair Ex sickle-cell disease GAG  GTG Ex sickle-cell disease GAG  GTG (glutamic acid  valine)

43 2) Base pair substitutions One complimentary pair is replaced by another One complimentary pair is replaced by another

44 substitutions Missense – the mutation makes sense (codes for an amino acid) but the wrong one Missense – the mutation makes sense (codes for an amino acid) but the wrong one Nonsense – Mutation produces a stop signal Nonsense – Mutation produces a stop signal

45 3) Insertions and Deletions Additions or losses of base pairs Additions or losses of base pairs

46 4) Frame shift mutation Occurs when the insertion or deletion is NOT a multiple of 3 EVERY amino acid incorrect after a frame shift More damaging overall

47

48 RNAi Interference RNA Interference RNA Small RNA that can promote or inhibit other mRNA Small RNA that can promote or inhibit other mRNA

49 Mutagens Physical or chemical agents that interact with DNA to cause mutations. Ex 6 legged frog Physical or chemical agents that interact with DNA to cause mutations. Ex 6 legged frog

50 DNA gone bad

51 Most mutations are harmful, not beneficial Or at best, not helpful Or at best, not helpful