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Protein Synthesis. The cell process in which individual cells construct proteins. Why do we need proteins?. Cell structure Cells are made up of 80% proteins Cell processes Hormones Enzymes Cell transport (cell membrane). What do we need for protein synthesis?. DNA
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Protein Synthesis The cell process in which individual cells construct proteins.
Why do we need proteins? • Cell structure • Cells are made up of 80% proteins • Cell processes • Hormones • Enzymes • Cell transport (cell membrane)
What do we need for protein synthesis? DNA contains the template for making mRNA during a process called transcription. DNA stays only in the nucleus.
RNA • mRNA -- messenger RNA • Makes a copy of DNA and takes it into the cytoplasm. • tRNA – transfer RNA • Uses the code from mRNA and collects amino acids found in the cytoplasm and takes them to the ribosomes. • rRNA – ribosomal RNA • Uses the amino acids and makes the proteins. This occurs in the ribosomes.
Ribosomes • Site of protein synthesis.
Let’s compare protein synthesis to building a house. • Lot – where house is built • Architect- plans • Materials – wood, nails • Contractor - Uses plans to buy materials • Builders – Uses plans to build house • Final Product - House ------Ribosome -----DNA -----Amino Acids -----mRNA ----- mRNA, tRNA and rRNA -----Proteins
Process of protein synthesis • In the Nucleus - DNA – blueprint • mRNA – copies DNA – this is called transcription • Takes this copy to tRNA and rRNA • In the cytoplasm – tRNA uses mRNA’s template to collect amino acids and takes them to the ribosomes • In the ribosomes – rRNA decodes mRNA for making proteins and interacts with tRNA to make proteins. • this is called translation
What is needed for protein synthesis • Amino acids are the monomers of proteins. • Chains of amino acids make a protein. • 3 bases in a row is called a codon – amino acid • The opposite 3 bases in a row is called an anticodon.
The two steps in protein synthesis are: • Transcription- what does this mean? • Translation – what does this mean?
Transcription • DNA ►mRNA • Location = nucleus • Steps • a. Enzyme binds to DNA, unzips it • b. mRNA copy of gene made • from DNA template • *U replaces T in RNA
Translation • Steps of Translation • 1. mRNA moves to cytoplasm, • binds to ribosome • 2. tRNAanticodon brings the amino acid to the ribosome • 3. rRNA assembles the protein by reading mRNA and directing tRNA.