DNA, RNA & Protein Synthesis Unit 5

Notes DNA Structure

DNA Structure DEOXYRIBONUCLEIC ACID NUCLEOTIDE PHOSPHATE SUGAR (DEOXYRIBOSE) NITROGEN BASE 1. DNA Structure 2. Journey into DNA 3. DNA to Protein

DNA Structure GENETIC INFO PROTEINS THYMINE ADENINE CYTOSINE GUANINE   DNA looks like a twisted ladder. This shape is known as a _______________________. DOUBLE HELIX

pRACTICE 4 COMPLEMENTARY COMPLEMENTARY BASE PAIRING RULE Circle one nucleotide. How many nucleotides are in this picture? We say A is _____________________ to T and C is ________________________ to G. this is the ____________________________. 4 COMPLEMENTARY COMPLEMENTARY BASE PAIRING RULE

Steps of DNA Replication DNA replicates before An ENZYME (called comes in and breaks the bonds between the base pairs which causes the strand of DNA to split or “unzips” (what is left looks like a ladder cut in two). The appropriate NUCLEOTIDE are then matched up (by another enzyme called . What you are left with is identical strands of DNA. A CELL DIVIDES HELICASE HYDROGEN POLYMERASE TWO

DNA Replication This mode of replication is called replication because each parental strand is used as a model (or template) for the generation of the new daughter (or complementary) strand. Color the backbone of original strand blue and the newly formed strand red. Identify the parts of the DNA molecule below as the original strand or the new strand. SEMICONSERVATIVE 4. ORIGINAL 5. NEW 6. ORIGINAL 7. NEW

DNA vs RNA & Protein Synthesis

DNA vs RNA & Protein Synthesis DEOXYRIBONUCLEIC ACID RIBONUCLEIC ACID NUCLEOTIDE HAS GENETIC INFO (CODE) TO MAKE PROTEINS HELPS MAKE PROTEINS 2 1 DEOXYRIBOSE RIBOSE A, T, C, G A, U, C, G NUCLEUS, CYTOPLASM, RIBOSOME NUCLEUS OF EUKARYOTES

DNA vs RNA & Protein Synthesis Three types of RNA: RNA (mRNA)– carriers the code from the DNA in the to the in the cytoplasm. Every three mRNA nucleotides is a How many are in the mRNA pictured below? MESSENGER NUCLEUS RIBOSOME CODON FOUR mRNA Codon

DNA vs RNA & Protein Synthesis RNA (rRNA) combines with proteins to make up the Made up of two subunits that snap together around the mRNA. RIBOSOMAL RIBOSOME rRNA (& protein)

DNA vs RNA & Protein Synthesis RNA (tRNA) is the complement to the mRNA. Its job is to bring to the ribosome to make the protein. The 3 letters on the tRNA is called an How are codons related to anticodons? TRANSFER AMINO ACIDS tRNA ANTICODON THEY ARE COMPLEMENTS OF EACH OTHER

Protein Synthesis

Enzymes Hemoglobin Cellular Respiration ATP Insulin Integral proteins So why do we even need to make proteins???? Here are several important proteins. ________________ - help with the chemical reactions in your body (metabolism). __________________ - covers the red blood cells and helps carry oxygen to all the cells in your body. Remember your body needs oxygen to undergo __________________________ to produce 38 __________ molecules giving your body energy. ________________ - helps maintain blood sugar homeostasis. Excess glucose is stored as glycogen in the muscles and liver. ______________________ - Forms channels in the cell membrane to help transport substances in and out of the cell ________________ - These help with growth and development Makes up your muscles that help your body move. Is every protein made at all times within an organism? Enzymes Hemoglobin Cellular Respiration ATP Insulin Integral proteins Hormones No, this would be a waste of time & energy. Proteins are made when needed.

NUCLEUS RIBOSOME Flow chart of Protein Synthesis (Label the arrows with the 2 steps). TRANSCRIPTION TRANSLATION protein DNA mRNA The DNA contains the code for making proteins. But DNA cannot leave the safety of the ______________. Therefore, mRNA is formed from the DNA and leaves the nucleus taking the message out to the ___________________ where proteins are made. NUCLEUS RIBOSOME

Protein Synthesis First Step = Transcription Occurs in the 1. DNA & Protein Synthesis Rap 2. Interactive DNA Replication & Protein Synthesis First Step = Transcription Occurs in the is used to form Second Step = Translation Occurs at the The tRNA picks up a specific in the cytoplasm and ‘travels’ to the mRNA (which is attached to the ). The tRNA attaches to the mRNA. When 2 tRNA molecules are next to one another at the ribosome a bond forms between the 2 amino acids. NUCLEUS DNA mRNA RIBOSOME AMINO ACID RIBOSOME PEPTIDE

After all the amino acids are put together, the protein is not functional until it ___________________ up into it’s 3-D shape. FOLDS

Diagram of Protein Synthesis (Transcription + Translation) Label Name A NUCLEUS C RIBOSOME B mRNA D tRNA E ANTICODON F CODON G H AMINO ACID H

Dna mutations CHANGE POINT FRAMESHIFT POINT SUBSTITUTION FRAMESHIFT 2 Main types of DNA mutations: If the DNA mutates then the protein may ___________________. ____________ or ______________________ - one base is replaced with a different base _______________________ - a base is inserted or deleted so the entire sequence is changed from that point on. Example: Normal Protein: - The red cat ate the fat rat. __________________ Mutation - The red hat ate the fat rat. _________________ Mutation - The reb dca tat eth efa tra t Causes of Mutations: Random errors in DNA replication mutagens – physical or chemical agents that cause mutations Ex: x-rays, UV rays Mutations are not always bad –they are a source of genetic diversity   CHANGE POINT SUBSTITUTION FRAMESHIFT POINT FRAMESHIFT

Protein Synthesis C A G G U C Glutamine

Protein Synthesis STOP MAKING THE PROTEIN, SIGNIFIES THE END. C A G G U C GLUTAMINE A UUU PHENYLALANINE C T CCU GLYCINE TAC AUG UAC CUA GAU LEUCINE CAC CAC 3 STOP CODONS (UAA, UGA, UAG) STOP MAKING THE PROTEIN, SIGNIFIES THE END. MUTATION – AND GET A NON-FUNCTIONAL PROTEIN TRANSCRIPTION TRANSLATION

Mutations

Mutations Causes of Mutations: Random errors in DNA replication 1. DNA Mutation Causing Cancer 2. How Mutations Work 3. Mutations 4. Mutations - sickle shaped cells Causes of Mutations: Random errors in DNA replication mutagens – physical or chemical agents that cause mutations Ex: x-rays, UV rays Mutations are not always bad –they are a source of genetic diversity