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PROTEIN SYNTHESIS copyright cmassengale1
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Starting with DNA DNA is the molecule that stores genetic information in the nucleus.DNA is the molecule that stores genetic information in the nucleus. It is a “code” that builds the molecules of life (proteins).It is a “code” that builds the molecules of life (proteins). DNA stays in the nucleus, but molecules are built in the cytoplasm of the cell.DNA stays in the nucleus, but molecules are built in the cytoplasm of the cell. So, the code must be copied and moved out into the cytoplasm, where proteins are assembled.So, the code must be copied and moved out into the cytoplasm, where proteins are assembled. This process is called PROTEIN SYNTHESISThis process is called PROTEIN SYNTHESIS 2
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3 Genes & Proteins Proteins are made of amino acids linked together by peptide bonds 20 different amino acids Amino acids chains are called polypeptides Segment of DNA that codes for the amino acid sequence in a protein are called genes
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RNA copyright cmassengale4
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RNA (ribonucleic acid) The nucleic acid that carries the genetic information on DNA from the nucleus out to the cytoplasm, where proteins will be made. copyright cmassengale 5
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RNA is similar to DNA 1. They both are made up of nucleotides 2. They both have a sugar 3. They both have 4 nitrogen bases 4. They both have a phosphate 6
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RNA Differs from DNA DNA 1.DNA has a sugar deoxyribose 2.DNA contains the base thymine (T) 3.DNA molecule is double-stranded RNA 1.RNA has a sugar ribose 2.RNA has uracil (U) 3.RNA is single- stranded 7
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Roles of RNA and DNA DNA is the MASTER PLAN RNA is the BLUEPRINT of the Master Plan copyright cmassengale8
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Structure of RNA copyright cmassengale9
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Types of RNA copyright cmassengale 10
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3 KINDS OF RNA _________________RNA (mRNA) Copies the code from DNA and carries it out. _________________RNA (rRNA) With proteins, it forms ribosomes _________________RNA (tRNA) Matches mRNA to “transfer” the correct amino acids to make a protein. rRNA and t-RNA images from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved mRNA image from http://wps.prenhall.com/wps/media/tmp/labeling/1140654_dyn.gif RIBOSOMAL TRANSFER MESSENGER
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Remember… The purpose of DNA is to store and transmit the genetic code so that…… Proteins can be made. copyright cmassengale 12
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Pathway to Making a Protein DNAmRNA tRNA (ribosomes) Protein copyright cmassengale14
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Protein Synthesis The process of making proteins from the code on DNA. Two phases: 1. Transcription 2. Translation copyright cmassengale15
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DNA RNA Protein copyright cmassengale16 Nuclear membrane Transcription RNA Processing Translation DNA Pre-mRNA mRNA Ribosome Protein Eukaryotic Cell
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Transcription and Translation copyright cmassengale17
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Transcription copyright cmassengale18
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Transcription The process of copying one strand of DNA onto mRNA Follows the base pair rule. copyright cmassengale19
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Template Strand copyright cmassengale20
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22 What is the enzyme responsible for the production of the mRNA molecule?
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23 RNA Polymerase Enzyme found in the nucleus Separates the two DNA strands by breaking the hydrogen bonds between the bases Then moves along one of the DNA strands and links RNA nucleotides together
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24 DNApre-mRNA RNA Polymerase
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25 Question: What would be the complementary RNA strand for the following DNA sequence? DNA 5’-GCGTATG-3’
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26 Answer: DNA 5’-GCGTATG-3’DNA 5’-GCGTATG-3’ RNA 3’-CGCAUAC-5’RNA 3’-CGCAUAC-5’
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You Practice! DNAAATCGG DNACATTAC DNAGCGATT copyright cmassengale27 RNA UUAGCC RNA GUAAUG RNA CGCUAA
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mRNA Processing After the DNA is transcribed, the mRNA, is edited –The entire DNA strand is copied. –Introns (which don’t code for proteins) are cut out. –Exons (which do code for proteins) are spliced back together. copyright cmassengale28
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Result of Transcription Introns are orange; Exons are green
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mRNA Transcript copyright cmassengale30 mRNA leaves the nucleus and goes to the ribosomes
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Messenger RNA (mRNA) ON the mRNA is a codon:ON the mRNA is a codon: a group of 3 nucleotides that will code for one amino acid. AUG – methionine or start codonAUG – methionine or start codon UAA, UAG, or UGA – stop codonsUAA, UAG, or UGA – stop codons GGC - GlycineGGC - Glycine copyright cmassengale31
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The Genetic Code A codon designates an amino acid There are 20 amino acids, but 64 possible codons copyright cmassengale32
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The Genetic Code copyright cmassengale33 Use the code by reading from the center to the outside Example: AUG codes for Methionine
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Name the Amino Acids GGG? UCA? CAU? GCA? AAA? copyright cmassengale34
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Review 1. What happens in transcription (step 1 of protein synthesis)? The code in DNA is copied onto an mRNA, in the nucleus. copyright cmassengale 35
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Review #2 Once the mRNA is made, it leaves the nucleus and goes to a _____________. copyright cmassengale 36 ribosome
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Review The mRNA is read by its “words”, which are called: _________, which are groups of 3 nucleotides. copyright cmassengale 37 codons
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USE THE DNA CODE PROVIDED TO MAKE A COMPLEMENTARY RNA COPY U C G A G C C T G T A G G C A G A CA U CC G U Review #1
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USE THE DNA CODE PROVIDED TO MAKE A COMPLEMENTARY RNA COPY A A G T T C A A G C A A T C G U U CG U UA G C Review #2
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Translation copyright cmassengale40
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Translation Translation is the process of using the mRNA’s code to build a protein mRNA tRNAprotein copyright cmassengale41
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Remember the types of RNA? Transfer RNA (tRNA) 42 Messenger RNA (mRNA) 3 bases are called a: Codon Anticodon
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Codons and Anticodons A codon is on mRNA. An anticodon is on the tRNA and is a complement to the codon. Example: Codon ACU Anticodon UGA copyright cmassengale43 UGA ACU
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THE mRNA strands’ codons determine the complementary tRNA strands’ anticodons C U G A U G A A G C A U G A C U U C G U A U A C mRNA (Codons) tRNA (anticodons)
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Name the anticodons to these codons: CCU UAG GUC AGU CUA copyright cmassengale45 GGA AUC CAG UCA GAU
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Translation Steps 1. Anticodons on the tRNA match up with the codons on mRNA. 2. Each tRNA carries one amino acid. 3. The amino acids are joined to form proteins. (Happens in the ribosomes.) copyright cmassengale46
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___________ on tRNA matches up with ________ on mRNA Images modified from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved ANTICODON CODON EACH tRNA carries only one kind of _____________ amino acid
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Copyright Pearson Prentice Hall Translation
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Copyright Pearson Prentice Hall Translation tRNA Ribosome mRNA Lysine Translation direction
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Copyright Pearson Prentice Hall Translation Protein Ribosome tRNA mRNA
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End Product –The Protein! A sequence of amino acids bonded together copyright cmassengale51 aa1 aa2 aa3 aa4 aa5 aa200 aa199
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USE THE mRNA CODE PROVIDED TO ADD THE COMPLEMENTARY tRNA C U G A U G A A G C A U G A C U U C G U AU A C Anticodons #7
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USE THE mRNA CODE PROVIDED TO ADD THE COMPLEMENTARY tRNA C U G A U G A A G C A U G A C U U C G U A U A C #8
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USE THE mRNA CODE PROVIDED TO ADD THE COMPLEMENTARY tRNA C U G A U G A A G C A U G A C U U C G U A U A C #9
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USE THE mRNA CODE PROVIDED TO ADD THE COMPLEMENTARY tRNA C U G A U G A A G C A U G A C U U CG U A #10
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USE THE mRNA CODE PROVIDED TO ADD THE COMPLEMENTARY tRNA C U G A U G A A G C A U G A C G U A #11
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USE THE CODON WHEEL TO TELL THE AMINO ACID SEQUENCE OF THE PROTEIN THIS mRNA WILL MAKE ALANINE - C A G G C A G C U U U U GLUTAMINE - PHENYLALANINE ALANINE - #12
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USE THE CODON WHEEL TO TELL THE AMINO ACID SEQUENCE OF THE PROTEIN THIS mRNA WILL MAKE HISTIDINE - G U C A G C C A U U G A VALINE - STOP SERINE - #13
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DNA → DNA ____________ DNA → RNA ____________ RNA → Protein ___________ REPLICATION TRANSCRIPTION TRANSLATION Closure Fill in the blanks with the correct process.
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copyright cmassengale60
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