DNA & PROTEIN SNTHESIS (Words to Know) 12. Nucleus 13. Protein Synthesis 14. Replication 15. Hydrogen Bonds 16. Complementary Base Pairs 17 Amino Acids 18 Nucleotide 19. DNA 20. Proteins 21. Double Helix 22. Watson & Crick 23. Purines 24. Pyrimidines 25. RNA 1. Transfer RNA 2. Peptide Bond 3. Dipeptide Bond 4. ATP 5. Translation 6. Anticodon 7. Transcription 8. Messenger RNA 9. Codon 10. Ribosomal RNA 11. Ribosomes

DNA & Genes CHAPTER 11 relating the structure of DNA to its function the role of DNA in protein production distinguish amongst different types of mutations.

DNA Molecule of Life Proteins are important components of living cells. Metabolism of cells is controlled by proteins called enzymes. Proteins are essential for life. Every cell is capable of making all the thousands of different kinds of proteins it may need.

Modern Genetics DNA of the chromosomes is the genetic material that is passed from generation to generation. Genes are sections of DNA. DNA controls cellular activities by controlling the production of enzymes.

Think On This… How does the cell synthesize proteins? What determines the kinds of enzymes present in each cell?

The molecule that controls the production of proteins is a nucleic acid called Deoxyribonucleic Acid (DNA). DNA is found in the chromosomes in the nucleus. DNA carries information for running the cell. DNA is made of nucleotides.

DNA is made up of nucleotides DNA Structure DNA is made up of nucleotides Nucleotides Have Three Parts Simple Sugar (5-carbon sugar) Phosphate group Nitrogen Base

Looking at the Structure of DNA In 1953 Watson and Crick solved the puzzle (p. 290 Fig. 11:3) These two scientists viewed x-ray images of DNA crystals that were created by Rosalind Franklin and Maurice Wilkins. DNA Structure Resembles a ladder sides: sugar and phosphate rungs (steps): complementary pairs of nitrogen bases

The structure (shape) of the DNA is referred to as a double helix.

DNA Bases In DNA, there are four possible nitrogen bases: adenine (A) guanine (G) cytosine (C) thymine (T)

4 Possible Nitrogen Bases Purines Adenine (A) Guanine (G) Pyrimidines Thymine (T) Cytosine (C) Base Pair Rule Adenine (A) to Thymine (T) And Guanine (G) to Cytosine (C)

DNA Replication

Replication of DNA DNA molecules can build an exact copy of itself. This is called Replication. (ATP is the energy source) Replication is important for reproduction and must occur every time a cell divides. That way each cell has a complete set of instructions for making proteins.

: Protein Synthesis REMEMBER: DNA is in the Nucleus Proteins are synthesized in the Ribosomes “ How can the information get to the ribosomes?” By coping a near message >>mRNA (messenger RNA) The process of transferring the information from DNA to RNA is called transcription

Transferring the info…. To carry the genetic message from the nucleus into the cytoplasm we have mRNA. Any RNA strand is a direct order from the DNA.

RNA Structure (looks like one half of a zipper) The Sugar is Ribose Single Strand Bases are: Adenine (A) to Uracil (U) Guanine (G) to Cytosine (C) **Thymine is NOT found in RNA ** Thymine is substituted with Uracil

3 Types of RNA mRNA (messenger RNA) *Carries genetic information from nucleus to ribosomes. rRNA (ribosomal RNA) *Found in ribosomes *binds to mRNA and uses instructions to assemble the amino acids in the correct order tRNA (transfer RNA) * Found in the cytoplasm * Carries amino acids in the cytoplasm to the ribosomes

DNA….to Proteins DNA Replicates….mRNA carries message to the Ribosome…

The Genetic Code EXAMPLE There are 4 bases There are 20 different kinds of amino acids in cells (A.A. are the building blocks of proteins) The groups of three bases (3 letter code) in mRNA are called codons or triplets. AUA, Codon Or Triplet EXAMPLE UUU, Codon Or triplet ACG, Codon Or Triplet

The Genetic Code Each codon codes for a particular A.A. Each codon always codes for the same A.A The sequence can be different…this gives rise to different proteins. There are 64 possible 3 letter code words. Only 20 common A.A. Some codons do not code for A.A., they provide instructions for making the proteins Example: UAA (is a stop codon) this indicates that the protein ends at this point Example:AUG (is a start codon and codes for an A.A.)

TRANSLATION (see p. 294) Bonding A. A. to form proteins is called Translation (from mRNA to Protein) tRNA: * Is shaped like a cloverleaf (Fig. 11:8) *one end has an attached site for an A.A. * the other end has an exposed base triplet called and anticodon

Information is decoded Translation: Information is decoded * If a codon (3 bases on mRNA) is AUC …..then Its’ anticodon (3 bases on tRNA) is UAG *In the cytoplasm are the A. A. necessary for building proteins. tRNA will carry the proper A.A. to the mRNA and line them in the correct order. * Once the RNA attaches to its’ specific A.A. the combination moves toward a ribosome (protein factory)

Transfer RNA (tRNA) (p. 293) Three base anticodon

Amino Acid Codons

Effects of Mutation: (p. 298) Genetic Changes (11:3) Mutation: any change in the DNA sequence. Mutagen: any agent that can cause a change in DNA…(radiation, chemicals, and even high temperatures. Effects of Mutation: (p. 298) Point mutation: Change in a single base pair in DNA Frameshift Mutation: A single base is added or deleted from DNA

Four Kinds of Chromosomal Mutations (see.p. 300) Deletion: part of the chromosome is left out Insertion: part of the a chromatid breaks off and attaches to its sister chromatid Inversion: part of a chromosome breaks off and reattaches backwards Translocation: part of one chromosome breaks off and is added to a different chromosome

Terms Protein: A complex chain of amino acids essential in cell structure. DNA: A nucleic acid “molecule of life” Nucleus: Control center of the cell Protein Synthesis: the making of proteins Double Helix: the shape of DNA Watson & Crick: Constructed DNA model Ribosomes: Protein factory ATP: Energy used to break chemical bonds

More Terms Hydrogen Bonds: holds nitrogen bases together (they are weak) Replication: ability to build an identical copy of itself Messenger RNA (mRNA): Brings the code from the DNA to the ribosomes (sets of 3 are codons) Transcription: Process by which the DNA code is copied onto a strand of mRNA. Nucleotide: contains a 5-carbon sugar, nitrogen base and phosphate Amino Acid: the building blocks of proteins Purines: Adenine and Guanine Pyrimidines: Cytosine and Thymine

More Terms 17. Complementary Base Pair: A (to) T C (to) G RNA: Ribonucleic Acid Ribosomal RNA (rRNA): makes up the major part of ribosomes Codon: a sequence of 3 nucleotide bases that code for 2 amino acid in a protein…(found on mRNA) 21. Anticodon: An exposed base triplet at the end of the RNA (found on tRNA) Translation: Process of bonding A.A. in a sequence to form a protein Dipeptide Bond: 2 or more A. A. joined Peptide Bond: the bond that forms between A.A. to join another Transfer RNA (tRNA): “Picks up” and carries A.A. to the ribosomes

DNA Worksheet Name the molecule of life. What are proteins essential for? What are the building blocks for proteins? Who studied the structure of DNA? Where do you find DNA? What is the job DNA? Name the 4 bases in DNA. How do these bases pair? What does the DNA structure look like? What is the protein factory of the cell? Name three types of RNA.. Name two jobs of RNA.. What base does adenine bond with? How many bases does it take to make one amino acid? How many amino acids are common? What is the anticodon for ACG? If DNA read A-T-T-A-C-G-G-C-C what would the RNA read? Why is DNA replication important?

DNA & Protein Synthesis 1. What is the shape of the DNA molecule? 2. Who are the two men that proposed DNA? 3. What base will pair with cytosine? 4. What base will pair with adenine? 5. The shape of the DNA structure is twisted, it is better known as ___. 6. What is the process called when DNA copies itself? 7. Name the three types of RNA. 8. What is transcription? 9. What is translation? 10. What kind of information does the DNA contain?

DNA Story In the living world there are millions of different kinds of (1) ____. How are these made by cells? It has been found that protein synthesis in a cell is controlled by a complex macromolecule called (2)_____. This compound is not a protein but a (3)______. A nucleic acid is made up of 3 parts. A 5-Carbon (4)____ molecule, nitrogen containing (5)____, and a (6)____ group. DNA looks like a ladder twisted into a shape known as (7)____. Each side of the “ladder” is a long strand made of connecting nucleic acids. Each base is joined by a weak (8) ___ to a base on the other strand forming “rungs” in the ladder. The bases form complementary pairs. Adenine bonds with (9) ____; cytosine bonds with (10)___. During DNA (11)_____, the hydrogen bonds break and each strand finds new complimentary bases.

DNA Story cont. In the nucleic acid RNA, adenine always pairs with (12)______. There are three kinds of RNA. (13)______ RNA carries genetic information from the nucleus to the cytoplasm. During (14)____. Information is transferred from DNA in the nucleus to mRNA. The DNA molecule opens up and the mRNA forms a single complementary (15)_____. The four bases of RNA can be combined into 64 different (16)______ combinations. Each triple, known as a (17)___, codes for one specific (18)____. The order of the triples will determine the order of the amino acids in the ______ (19) synthesized. Word Bank PROTEIN AMINO ACIDS SUGAR BASE HYDROGEN MESSENGER PROTEINS THYMINE REPLICATION STRAND THREE BASE CONDON GUANINE PHOSPHATE DNA DOUBLE HELIZ URACIL TRANSCRIPTION NUCLEIC ACID