Protein Synthesis Reading the DNA molecule to make proteins.

Genes and Proteins Nucleotides contain information which is put to work through the production of proteins.Nucleotides contain information which is put to work through the production of proteins. Proteins are 3D shapes composed of a long chain of amino acids (A.A.)Proteins are 3D shapes composed of a long chain of amino acids (A.A.) Each human cell contains about 80,000 genes.Each human cell contains about 80,000 genes.

How DNA controls cell functions 1.DNA instructs cell to make amino acids. 2.Amino Acids link together to form proteins.  20 different amino acids. 3.Proteins control the cells chemistry and what a cell will do. 4.Proteins allow us to display our traits.

What are the “players” in making Proteins? DNA stores the code to make and build proteinsDNA stores the code to make and build proteins RNA brings amino acids for protein synthesis.RNA brings amino acids for protein synthesis. Amino acid by amino acid, the proteins are assembled.Amino acid by amino acid, the proteins are assembled. DNA  Ribosomes  Amino Acid  Protein

RNA is like DNA, but is different in 3 key ways: 1.RNA is single stranded 2.The sugar in RNA is RIBOSE 3.The four Nitrogen bases are: 1.Cytosine 2.Guanine 3.Adenine 4.Uracil (replaces Thymine)

Three Different kinds of RNA 1.Messenger RNA (mRNA) 2.Ribosomal RNA (rRNA) 3.Transfer RNA (tRNA)

Messenger RNA (mRNA) 1.Carries genetic information from DNA (in nucleus) to ribosomes (in cytoplasm) 2.“Bar Code”

Ribosomal RNA (rRNA) 1.Clamp on to mRNA and reads its information to assemble amino acids in the correct order. 2.Connects the amino acids together (Makes the protein) 3.Makes up the Ribosome (with Proteins) 4.“Register/Scanner”

Transfer RNA (tRNA) 1.Transports Amino Acids to the ribosome to be assembled into a protein. 2.“Conveyer Belt”

Transcription: Transfer of information from DNA to Ribosomes Similar to DNA replication (4 step process)Similar to DNA replication (4 step process) 1.DNA Molecule unzips, and unpaired bases are exposed 2.RNA NUCLEOTIDES base pair with complementary DNA nucleotides on the Master Strand.

DNA master strand sequence: AGC TAA CCG mRNA base-pair strand sequence: UCG AUU GGC

3.When base pairing is completed RNA nucleotides combine (develop backbone) to form mRNA. 4.DNA reconnects and mRNA leaves the nucleus to enter the cytoplasm.

The Genetic Code mRNA is the genetic messenger, which carries the message on how to build the proteins.mRNA is the genetic messenger, which carries the message on how to build the proteins. Proteins are built from chains of smaller molecules called Amino Acids.Proteins are built from chains of smaller molecules called Amino Acids. A code is needed to convert mRNA into proteins.A code is needed to convert mRNA into proteins. There are 20 different amino acids with only 4 types of bases: A, U, G, CThere are 20 different amino acids with only 4 types of bases: A, U, G, C

How the bases form a code for Proteins: Codon is a 3 nucleotide sequence that codes for an amino acid.Codon is a 3 nucleotide sequence that codes for an amino acid. The order of nitrogen bases in the mRNA will determine the type and order of amino acids in a protein.The order of nitrogen bases in the mRNA will determine the type and order of amino acids in a protein. There are many possible combos, and mRNA codons.There are many possible combos, and mRNA codons. AUG = start protein productionAUG = start protein production UAA = stop protein productionUAA = stop protein production

DNA and m-RNA A T G T C A G A C G ( Master DNA ) U A C A G U C U G C (m-RNA Strand) 3 base sequence in m-RNA is called a codon DNA and m-RNA molecules separate and the m-RNA molecules travel to the ribosomes

Translation: from mRNA to Protein Translation = converting info in a sequence of nitrogen bases in mRNA into a sequence of amino acids that make up a protein.Translation = converting info in a sequence of nitrogen bases in mRNA into a sequence of amino acids that make up a protein. Occurs in the ribosomes (in cell’s cytoplasm)Occurs in the ribosomes (in cell’s cytoplasm)

Translation: from mRNA to Protein 1.The mRNA sequence (protein blueprint) passes through the rRNA which acts as a register/scanner 2.tRNA attaches to amino acids in cytoplasm and brings them to the rRNA One end of tRNA molecule is attached to one of 20 different A.A., the opposite end has a 3 base sequence called an anticodonOne end of tRNA molecule is attached to one of 20 different A.A., the opposite end has a 3 base sequence called an anticodon

3.Anticodon of tRNA matches and bonds to correct codon on mRNA molecule 4.tRNA molecules detach and leaves the amino acid behind for the rRNA to connect to the AA sequence being formed. 5.Process is repeated until the “STOP” codon is reached… the Amino Acid chain breaks off, and a complete protein is made.

Errors in Stored Information Cells may make proteins that have amino acids in the wrong orderCells may make proteins that have amino acids in the wrong order 1.Errors are the result of change in base sequences in a DNA molecule 2.These errors are called MUTATIONS

Mutations in Reproductive Cells Mutations affect the reproductive cells of an organism by changing the sequence of nucleotides in a gene in the egg or spermMutations affect the reproductive cells of an organism by changing the sequence of nucleotides in a gene in the egg or sperm If these cells take part in fertilization, the changed gene would be part of the genetic makeup of the offspringIf these cells take part in fertilization, the changed gene would be part of the genetic makeup of the offspring This mutation may produce negative results ( death of embryo) or positive results in very few cases ( faster or stronger individuals)This mutation may produce negative results ( death of embryo) or positive results in very few cases ( faster or stronger individuals)

Mutations in Body Cells If radiation hit a body cell such as your skin tissue, this would not be passed on to your offspring. However, severe effects may result for the individual such as cancer.If radiation hit a body cell such as your skin tissue, this would not be passed on to your offspring. However, severe effects may result for the individual such as cancer. Aging is the result of a buildup of cells that do not work properlyAging is the result of a buildup of cells that do not work properly Some mutations effect cell division which results in cells either dividing rapidly or not dividing at all.Some mutations effect cell division which results in cells either dividing rapidly or not dividing at all.

3 types of Mutations: Point Mutation – A change in a single base pair Ex. CAT to CAR = incorrect Amino Acid (replaced)Point Mutation – A change in a single base pair Ex. CAT to CAR = incorrect Amino Acid (replaced) Frameshift – A single base is either added or deleted. Results in an entirely new amino acid sequence. (addition or deletion) Frameshift – A single base is either added or deleted. Results in an entirely new amino acid sequence. (addition or deletion) Chromosomal – Affect the distribution of genes to gametes during meiosis. They cause non-disjunction: the failure of chromosomes to separateChromosomal – Affect the distribution of genes to gametes during meiosis. They cause non-disjunction: the failure of chromosomes to separate

All 3 mutations will cause defective proteins to be produced Cells or organism with mutation will not work correctlyCells or organism with mutation will not work correctly Cells or organism with mutation may dieCells or organism with mutation may die

Causes of Mutations Many occur naturallyMany occur naturally Materials causing mutations are called mutagens.Materials causing mutations are called mutagens. May be influenced by the environment:May be influenced by the environment: 1. Chemicals 1. Chemicals 2. Ultraviolet light 2. Ultraviolet light 3. Radiation ( large amt. of energy = bursts DNA) 3. Radiation ( large amt. of energy = bursts DNA) 4. High temperatures 4. High temperatures

Assignment Mini Lab pg 306Mini Lab pg 306 Do a lab write up, answer the analysis ?’s 1-3 and write a conclusion statement.Do a lab write up, answer the analysis ?’s 1-3 and write a conclusion statement. Problem Solving lab – pg 305Problem Solving lab – pg 305 Answer the Thinking Critically Questions 1-4Answer the Thinking Critically Questions 1-4