BELL RINGER What are the base pairing rules for DNA replication? Where does DNA Replication occur? What is the function of DNA? Do all of your cells have the exact same DNA?

The building of proteins Protein Synthesis The building of proteins This PowerPoint has many animated slide progressions. You may only want to print the following slides: 1-11; 33-47; 62; 64-65

Protein Synthesis Protein Synthesis is the building of Proteins The monomer of a protein is an amino acid DNA holds the instructions to synthesize proteins Functions of proteins include Structure (hair, skin, claws, muscle) Cell communication (hormones) Digestion and synthesis (enzymes)

SO…how does a cell make proteins anyway?

There are two important nucleic acids involved in this process... DNA Deoxyribonucleic acid RNA Ribonucleic acid What is the monomer of a nucleic acid? Nucleotide!! DNA and RNA are both nucleic acids.

Let’s Compare DNA & RNA RNA: ribonucleic acid RNA is SINGLE stranded Sugar = ribose RNA contains bases Adenine, URACIL Cytosine and Guanine RNA is found in both the NUCLEUS AND CYTOPLASM DNA: deoxyribonucleic acid DNA is DOUBLE stranded Sugar = deoxyribose DNA contains bases Adenine, Thymine, Guanine, Cytosine. DNA found ONLY in the NUCLEUS This is a review of DNA and RNA. The slide is animated; each statement comes up automatically

Let’s Compare DNA & RNA RNA: ribonucleic acid RNA is SINGLE stranded Sugar = ribose RNA contains bases Adenine, URACIL Cytosine and Guanine RNA is found in both the NUCLEUS AND CYTOPLASM DNA: deoxyribonucleic acid DNA is DOUBLE stranded Sugar = deoxyribose DNA contains bases Adenine, Thymine, Guanine, Cytosine. DNA found ONLY in the NUCLEUS Both contain Nucleotides made of a sugar, phosphate and nitrogen base. Both have bases A, C, and G This is a review of DNA and RNA. The slide is animated; each statement comes up automatically

Nucleic Acid COMPLEMENTARY Base Rules DNA RNA A – T C – G 5’ – 3’ A – U C – G

There are three types of RNA mRNA mRNA: messenger RNA Transcription 3 mRNA bases = codon = amino acid tRNA: transfer RNA Translation 3 tRNA bases = anTi-codon Found in the cytoplasm tRNA towing Amino acid Remind students that there are three different RNA molecules that are involved with protein synthesis and briefly go over their function. mRNA: messenger RNA. It carries the DNA message from the nucleus to the ribosomes. tRNA: transfer RNA. It carries amino acids from the cytoplasm to the ribosomes. rRNA: ribosomal RNA. It is found at the ribosomes. The slide is animated; each statement and picture comes up automatically rRNA: ribosomal RNA

Protein Synthesis(to make) transcription translation Trait During gene expression, the information in DNA is first transcribed in the nucleus as a molecule of mRNA and then translated in the cytoplasm and used to build a protein. DNA RNA Protein

Transcription and Translation The process of going from DNA to mRNA is Transcription The process of going from mRNA to protein is Translation

Protein Synthesis

Transcription (DNA mRNA) Occurs in the nucleus of a eukaryotic cell Steps to transcription DNA unzips itself mRNA is made by forming the complementary strand along the unzipped portion of DNA DNA’s code is copied into groups of three bases called a codon 3 mRNA bases = 1 codon = 1 amino acid mRNA will then leave the nucleus and find a ribosome in the cytoplasm for the next step in protein synthesis Practice: transcribe the DNA to mRNA AAA CGA TCC GAT CAT GGG

Practice Transcribing (DNA to mRNA) Think…which rules apply (DNA or RNA)…any time RNA is involved RNA rules apply (A-U and C-G). DNA strand: AAA CGA TCC GAT CAT GGG Transcription mRNA strand: UUU GCU AGG CUA GUA CCC How many codons are in the mRNA strand above? 6 How many amino acids will be coded for in the mRNA strand above? 6

Amino Acids (monomer of proteins) There are 20 known amino acids present in living things Each mRNA codon “codes” for a specific amino acid 3 mRNA bases = 1 codon 1 codon = 1 amino acid We use a “codon chart” to determine what amino acid is being coded for A chain of amino acids is a protein

mRNA Codon chart U C A G First Base Second Base Third mRNA codon: AUC   U C A G Phenylalanine Leucine Serine Tyrosine Stop Cysteine Tryptophan Proline Histidine Glutamine Arginine U C A G Isoleucine Methionine Threonine Asparagine Lysine Valine Alanine Aspartic Acid Glutamic Acid Glycine First Base Second Base Third 2nd Explain how to use the chart to find the amino acids that are made. Chart taken from the University of Arizona’s Biology Project

Translation (mRNA protein) Translation is the process of going from mRNA to a protein tRNA reads the mRNA codons and brings back the appropriate amino acid to the ribosome tRNA is clover leaf shaped On one end it carries the amino acid like a tow truck At the other end it has a three letter triplet called an anti codon

tRNA structure: 2 parts Amino acid anTi-codon

Find the tRNA anticodon AUG CCA GCU GUA What type of RNA?

Translation- tRNA turns code into proteins anTi-codons are the complement to the mRNA codon 3 tRNA bases = anTi-codon = complement to codon

Protein synthesis Begins when a tRNA brings a START amino acid to a ribosome Continues until a STOP is delivered to a ribosome How does the ribosome know when to stop synthesizing a protein?

It is possible for some amino acids to have more than one codon. There are three stop codons…they are UAA, UGA and UAG. When a STOP codon is reached, the building of that protein is finished There is also one START codon…AUG. When a ribosome is delivered a START codon, it starts to build a protein This will continue until a STOP codon is delivered

Proteins The monomer (building block) of a protein is an amino acid Each mRNA codon = 1 amino acid Ribosomes bond the amino acids that are delivered by tRNA together to form different proteins The bonds between amino acids are called “peptide” bonds (peptide = protein)

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically

Here’s the process…animated! UACUGCUAA tyrosine AUG The slide is animated; translation occurs automatically

Here’s the process…animated! UACUGCUAA tyrosine AUG The slide is animated; translation occurs automatically

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine

Here’s the process…animated! UACUGCUAA threonine ACG The slide is animated; translation occurs automatically tyrosine

Here’s the process…animated! UACUGCUAA threonine ACG The slide is animated; translation occurs automatically tyrosine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine

Here’s the process…animated! UACUGCUAA isoleucine AUU The slide is animated; translation occurs automatically tyrosine threonine

Here’s the process…animated! UACUGCUAA isoleucine AUU The slide is animated; translation occurs automatically tyrosine threonine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine isoleucine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine isoleucine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine isoleucine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine isoleucine

Here’s the process…animated! UACUGCUAA The slide is animated; translation occurs automatically tyrosine threonine isoleucine

Can you tell the story? DNA mRNA amino acids tRNA mRNA Polypeptide (protein) 5' tRNA ribosome

Label the diagram Protein tRNA mRNA Amino acid Ribosome

The “Central Dogma” or BIG IDEA transcription translation DNA protein trait mRNA To get from the chemical language of DNA to the chemical language of proteins requires 2 major stages: transcription and translation replication

DNA  Proteins  Cells  Bodies

What is gene expression? ALL of the different characteristics of ALL organisms is a result of PROTEIN SYNTHESIS. You are seeing the physical expression of the SEQUENCE of NITROGEN BASES determined the proteins that will be expressed. (ATT CGC TGG) NOT

Differential Gene Expression All of the somatic (body) cells in an organism are genetically identical Differences between cell types (skin, muscle, kidney, blood, etc.) result from differential gene expression, the expression of different genes by cells with the same genome Gene expression is a regulated process Hormones signal the turning on and off of genes

Regulated Gene Expression Temperature will the turning on and off of protein synthesis which leads to gene expression in mammalian fur color

Mutations Mutations (errors) in DNA can result abnormalities in gene expression and can lead to diseases including cancer

In summary… DNA contains the instruction to syntesize proteins DNA never leaves the nucleus RNA acts as a set of working instructions for ribosomes to make proteins This process is also known as gene expression.