Protein Synthesis Protein Synthesis
Protein SynthesisProtein Synthesis
DNA ReviewDNA Review
The nucleotide bases will The nucleotide bases will point to the inside of the point to the inside of the DNA molecule while the DNA molecule while the outside (backbone) of the outside (backbone) of the DNA molecule will be made DNA molecule will be made of the sugar and phosphate of the sugar and phosphate moleculesmolecules
When complete the DNA When complete the DNA molecule forms a double molecule forms a double helix (two spiral sides helix (two spiral sides wrapped together)wrapped together)
CHROMOSOMES CONTAIN CHROMOSOMES CONTAIN DNADNA
The nucleus contains The nucleus contains chromatinchromatin
Chromatin is made of smaller Chromatin is made of smaller nucleosomesnucleosomes
A nucleosome is formed by a A nucleosome is formed by a DNA molecule wrapped DNA molecule wrapped around a protein “stick”around a protein “stick”
Looks like cotton candy Looks like cotton candy wrapped around the paper wrapped around the paper conecone
Protein SynthesisProtein Synthesis
Why is it important?Why is it important?
Cells are controlled by enzymes- Cells are controlled by enzymes- enzymes are proteinsenzymes are proteins
Almost every substance made by the cell Almost every substance made by the cell is or contains a stuctural proteinis or contains a stuctural protein
VocabularyVocabulary GeneGene- a portion of DNA that codes for a protein- - a portion of DNA that codes for a protein-
the “recipe” for a proteinthe “recipe” for a protein mRNAmRNA- messenger RNA- messenger RNA tRNAtRNA- transfer RNA- transfers amino acids- transfer RNA- transfers amino acids CodonCodon- mRNA’s complementary trio of bases- mRNA’s complementary trio of bases AnticodonAnticodon- tRNA’s complementary trio of bases- tRNA’s complementary trio of bases TranscriptionTranscription- mRNA making a template of - mRNA making a template of
DNA’s codeDNA’s code TranslationTranslation- tRNA “reading” mRNA’s code and - tRNA “reading” mRNA’s code and
transferring the amino acids necessary to form a transferring the amino acids necessary to form a proteinprotein
Two Steps to Protein Two Steps to Protein SynthesisSynthesis TranscriptionTranscription- takes place in - takes place in
the nucleus-mRNA makes the nucleus-mRNA makes template of DNA’s codetemplate of DNA’s code
TranslationTranslation- takes place on - takes place on the ribosome in the the ribosome in the cytoplasm- tRNA transfers cytoplasm- tRNA transfers amino acidsamino acids
Things to RememberThings to Remember
DNA contains the “recipes” for proteins- DNA contains the “recipes” for proteins- called genescalled genes
DNA is made of the bases adenine, DNA is made of the bases adenine, thymine, guanine and cytosinethymine, guanine and cytosine
A-T and C-GA-T and C-G RNA is made of the bases adenine, RNA is made of the bases adenine,
uracil, guanine and cytosineuracil, guanine and cytosine A-U and C-GA-U and C-G
TranscriptionTranscription
Takes place in the nucleusTakes place in the nucleus DNA unzipsDNA unzips mRNA makes a template of the DNA mRNA makes a template of the DNA
codecode mRNA copies the code three bases at a mRNA copies the code three bases at a
time- this is a time- this is a codoncodon
TranscriptionTranscription- mRNA - mRNA forms codonsforms codons
Translation- on the Translation- on the ribosome, tRNA transfers ribosome, tRNA transfers amino acidsamino acids
Another LookAnother Look
Another ViewAnother View
The four bases can combine in The four bases can combine in 64 different triplicate (codon) 64 different triplicate (codon) combinationscombinations
Each codon codes Each codon codes for a specific amino for a specific amino acidacid
Codon ChartCodon Chart
Another Codon ChartAnother Codon Chart
Protein StructureProtein Structure
A Few of The Finished A Few of The Finished Products! ProteinsProducts! Proteins
Think About It-Think About It-
LettersLetters→ Words→ Sentences→ Words→ Sentences
Sam hit the ball.Sam hit the ball. Bases→ Amino Acids→ ProteinsBases→ Amino Acids→ Proteins
View It!View It!
http://www.wisc-online.com/objects/index_tj.asp?objID=AP1302
http://www.pbs.org/wgbh/aso/tryit/dna/shockwave.html
Wrap UpWrap Up 1. DNA message is transcribed into messenger 1. DNA message is transcribed into messenger
RNA (mRNA)RNA (mRNA) 2. mRNA leaves the nucleus and attaches to a 2. mRNA leaves the nucleus and attaches to a
ribosomeribosome 3. Each three letter codon will attract a matching 3. Each three letter codon will attract a matching
three letter anti-codon of transfer RNA (tRNA) three letter anti-codon of transfer RNA (tRNA) 4. Each tRNA is carrying an amino acid “on its 4. Each tRNA is carrying an amino acid “on its
back”back” 5. As the tRNA molecules line up, their amino 5. As the tRNA molecules line up, their amino
acids also line upacids also line up 6. As the amino acids are lined up, they 6. As the amino acids are lined up, they
chemically bond to form a proteinchemically bond to form a protein
Mutations- Any error in the Mutations- Any error in the genetic codegenetic code
Can happen when:Can happen when: DNA is making new copies of itself DNA is making new copies of itself
(replication)(replication) DNA is being used to make messenger DNA is being used to make messenger
RNA (transcription)RNA (transcription) Transfer RNA is being attracted to the Transfer RNA is being attracted to the
messenger RNA at the ribosome messenger RNA at the ribosome (translation)(translation)
Types of MutationsTypes of Mutations
Point mutations happen when Point mutations happen when one or two bases are different one or two bases are different than they are supposed to bethan they are supposed to be
Frameshift mutations happen Frameshift mutations happen when extra bases are added or when extra bases are added or deleted deleted