Protein Synthesis Presentation 2025 PDF

Welcome to H. Bio Spring Semester 1  Gene Expression / Protein Synthesis pp. 204-212 (2nd half ch.10) How Proteins Are Made (from DNA to Proteins) DNA PROTEIN DNA Review DNA Structure Sides - alternating...

Welcome to H. Bio Spring Semester 1  Gene Expression / Protein Synthesis pp. 204-212 (2nd half ch.10) How Proteins Are Made (from DNA to Proteins) DNA PROTEIN DNA Review DNA Structure Sides - alternating phosphate and sugar groups Rungs - Nitrogen bases held together by a hydrogen bonds (purine bounded to a pyrimidine) – A pairs with T – G pairs with C DNA Review Fig. 10-10  Protein Review H Amino acid R O Composed of C, H, O & N N C C OH Made from 20 smaller units called amino acids H H Long chains of amino acids make polypeptides Protein Shape determines Function – The sequence (kind & number) of amino acids determines their shape. – 1˚, 2˚, 3˚, 4˚ Structures – Shape determines function Provide structure/support – Ex. Keratin makes up hair, ngernails Remember the tuber activity? fi Proteins are made by sending messenger RNA from the nucleus to the ribosome DNA blueprints in the nucleus mRNA Ribosomes Protein Proteins are built in the cytoplasm on the ribosomes  RNA vs. DNA Fig. 10-13 RNA is a nucleotide composed of: a) a single strand Begin New Stuff b) sugar: ribose c) nitrogen base: Uracil U is complimentary to A No Thymine in RNA  3 types of RNA *RNA helps turn DNA information into Proteins Fig. 10-14 mRNA-carries genetic information from DNA to the ribosomes (messenger) rRNA- forms ribosomes, site of protein making Ribosomal RNA is made up of 2 units and has 3 binding sites (a binding site for mRNA and 2 sites, P and A, for transfer RNA) tRNA- transfers an amino acid to the correct codon, the rst tRNA attaches to the P site (transfer) fi  Gene Expression-2 parts DNA RNA Proteins 1) Transcription DNA mRNA rRNA 2) Translation mRNA tRNA Amino Acids (Protein) illustration  Transcription Process of making mRNA from DNA g. 10-15 Occurs in the nucleus Starts at the Promotor- sequence of DNA that signals beginning of transcription. RNA polymerase produces mRNA from one strand of DNA After mRNA has been transcribed – introns are cut out (non-coding portion) – exons joined together (coding / expressed portion) – leaves nucleus --> ribosome fi Fig. 10-15 DNA mRNA Transcription - no audio 12 Transcription again Fig. 11-3 Introns- Noncoding regions Exons- Coding regions  Can you read the message? scgantyoxglurexadethhhhhfemfeqsddsaddfge scgantyoxglurexadethhhhhfemfeqsddsaddfge sgtxglxehhhhffqddddf Splice out introns can you read the message Join exons together 15  Translation Translation is the process of converting mRNA to amino acids Takes place in the cytoplasm at the ribosomes mRNA binds to the ribosome (rRNA) tRNA brings amino acids to the mRNA tRNA has a speci c amino acid and anti-codon that matches the codon found on mRNA Amino acids are bonded together in the correct order as read by mRNA Start & Stop signals initiate and complete translation Fig. 10-16 tRNA tRNA fi  Translation Fig. 10-16 17 rRNA- Makes the ribosome  Anticodon Codon (found on tRNA) (found on mRNA) Translation Animation  Translation Review #1 #3 #2 #5 #4 #6 #7 Where does this process take place?  Translation Fig. 10-16 24 Translation - no audio 25 Putting Transcription & Translation Together 26 How is the code deciphered from mRNA? polypeptide  20 Amino Acids 4 Nitrogen Bases (same in all organisms)  Table 10-1 p. 207 Read from Left to right Bases A.A. 1 4 2 16 3 64 Code read from mRNA The genetic code for life is translating the mRNA to Amino Acids at the ribosome.  Gene Expression 1) Transcription DNA mRNA 2) Translation mRNA rRNA Amino Acids tRNA illustration DNA mRNA A T T A G C T A T A T A Transcribe G C T A A T T A A T G C DNA mRNA A T A T A U G C G T A U T A U T A Transcribe U G C G T A U A T A T A U A T A G C G Code read from mRNA DNA mRNA Amino Acids A T A T A U Start G C G T A U T A U Phe T A Transcribe U Translate G C G T A U Val A T A T A U A T A Stop G C G 38 Mutations Changes in DNA that may or may not affect the intended protein Pages; 239-240  Universal code Code is redundant – several codons for each amino acid – “wobble” in the tRNA  Mutations Point mutations – single base change – base-pair substitution Substitution with no change – no amino acid change – redundancy in code Substitution with change – change one amino acid – change to stop codon When do mutations affect the next generation? Point mutation leads to Sickle cell anemia What kind of mutation? Sickle cell anemia  Mutations Frameshift – shift in the reading frame changes everything “downstream” – insertions adding base(s) – deletions losing base(s) Fig. 12-8 pg. 240 Figure 10-8 pg. 217 What are the effects of DNA/RNA mutations? Write two paragraphs about protein synthesis using the following words (underline each word.) DNA amino acids RNA proteins Transcription nucleus Translation cytoplasm RNA polymerase ribosomes mRNA gene expression rRNA tRNA codon anticodon  Gene Expression-2 parts DNA RNA Proteins 1) Transcription DNA mRNA rRNA 2) Translation mRNA tRNA Amino Acids illustration  Gene Regulation Why is it important to regulate the expression of genes?  Regulation of Gene Expression in Prokaryotes pp. 216-222 Arabinose Operon Operon - A cluster of genes which code for proteins The arabinose operon, found in ecoli bacteria inside your intestine, contains a group of genes which produce the 3 enzymes that breaks down arabinose. Bacteria Cell Arabinose operon 3 Enzymes Arabinose Xylulose 5-phosphate  Terms for Gene Regulation Promoter- A speci c sequence of DNA which RNA polymerase binds (signals the beginning of a gene.) RNA Polymerase- Enzyme for transcription, binds to the promoter Operator- Located between the promoter and structural genes, it is a speci c sequence of DNA where the repressor protein binds. Repressor Protein- Binds to the operator and prevents transcription. Inducer-(Arabinose) Binds to the repressor protein changing its conformation (shape) and removes from the operator. Arabinose absent: operon is off. Ara B Ara A Ara D fi fi  The arabinose operon is a cluster of genes that enables a bacterium to enzymes needed for arabinose metabolism only when arabinose is present Arabinose absent: The repressor protein is bound to the operator, and the arabinose operon is off off Arabinose metabolizing genes Arabinose present: The repressor protein detaches from the operator, and the arabinose repressor in on on Arabinose Arabinose is bound to the repressor  Arabinose operon: arabinose RNA Digestive pathway model polymerase When arabinose is present, binds to repressor protein & triggers repressor to release DNA RNA – induces transcription polymerase TATA repressor araB araC araD DNA repressor repressor protein promoter operator Arabinose Arabinose – repressor protein repressor complex conformational change in repressor protein!