PROTEIN SYNTHESIS What do you already know What

PROTEIN SYNTHESIS

What do you already know? § § § What does the word “synthesis” mean? What is the building block of protein? Where in the cell are proteins made? What is the function of proteins? What 3 letters do all sugars end with?

Structure of RNA § Ribose Sugar § Phosphate group § Nitrogenous bases. A U (not T) C G § Forms a nucleotide (just like DNA)

Post-it Activity: 1. On your post-it notes write • 2 things that only DNA has • 2 things that only RNA has • 1 thing in common 2. Place your post-it on the appropriate poster.

RNA differs from DNA 1. RNA has a sugar ribose DNA has a sugar deoxyribose 2. RNA contains uracil (U) DNA has thymine (T) 3. RNA molecule is single-stranded DNA is double-stranded

Transcription – Basics § Process that makes m. RNA (messenger RNA) from a gene (DNA) § m. RNA carries the genetic codes from the nucleus to the ribosomes § Occurs in the nucleus

Transcription – DNA m. RNA 1. DNA unzips into 2 separate strands 2. Enzymes pair up nucleotides according to RNA base pairing rules: Cytosine(C) pairs with Guanine(G) Uracil(U) pairs with Adenine(A) 3. A single strand of RNA has been produced. 4. Genetic code from DNA is transferred to m. RNA

So, after transcription, what is the complementary m. RNA strand from the following strand of DNA? § DNA – AGG CTT GGC CAA GCT § RNA –UCC GAA CCG GUU CGA §DNA- TAC CGG ATA CCG CAT GCG §RNA- AUG GCC UAU GGC GUA CGC

Brain Break § Find classmates that will help you complete the sequence of protein synthesis. § Once you have all the pieces (5 total), working with your group organize the picture/words into the correct order. § Have a teacher check your work then copy your sequence into your notes

Translation – m. RNA protein § Process where m. RNA is used to make proteins. § Occurs at the ribosomes § Ribsomes are made of r. RNA (ribosomal RNA)

Translation – m. RNA protein 1. The m. RNA leaves the nucleus and goes to the ribosomes. 2. The ribosome attaches to m. RNA 3. The m. RNA is read by ribosomes 3 nucleotides (codon) at a time 4. As the codons are read, t. RNA (transfer RNA) brings the appropriate amino acids and they are assembled in a long chain called a protein

Protein Synthesis Simulation § http: //www. wisconline. com/objects/index_tj. asp? obj. ID=A P 1302

Flow Map § § § Organize the pieces into the correct order Have a teacher check your answer Copy the correct sequence into your notes.

The Genetic Code § 3 RNA nucleotides code for 1 amino acid. § The strand AAACGUUCGCCC would be separated as AAA-CGUUCG-CCC § How do we figure out the amino acids? -we use the codon chart Lysine – Arginine – Serine – Proline

Genetic Codes

Universal Genetic Code DNA m. RNA codon G T G A T G G C A t. RNA anticodon C A C G U A U G A C C G U G C A Amino Acid Histodine Tyrosine Arginine

Protein Synthesis Amino acid protein t. RNA Ribosome r. RNA m. RNA

Protein Synthesis Amino acids t. RNA F E m. RNA A B DNA C D Ribosome r. RNA DNA making m. RNA H Transcription G Protein I Translation DNA → RNA → Proteins

Quick Review 1. How many nucleotides are needed to code for one amino acid? A. 1 B. 3 C. 4 D. 6

Quick Review 2. Uracil is found in…. . a) b) c) d) DNA Ribosomes Double Helix

Quick Review 3. What is one role of transfer RNA in the cell? A. preparing the genes for messenger RNA B. changing nitrogen bases into amino acids C. preparing messenger RNA for the ribosomes D. carrying amino acids to the ribosomes

Quick Review 4. The genetic information for making a protein must move from the nucleus to the cytoplasm. Which of these moves this information to the cytoplasm? A. a ribosome B. DNA C. RNA D. an amino acid

Quick Review 5. Which of these statements best explains how genes and proteins are related? A. Genes are segments of DNA that code for proteins. B. Proteins are segments of DNA that code for genes. C. Genes are the building blocks of proteins. D. Proteins are the building blocks of genes.