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Learn about the key differences between DNA and RNA in protein synthesis, the three main types of RNA, the role of proteins, and the steps involved in making a protein through transcription and translation. Explore the purpose and process of transcription and translation with detailed explanations and helpful illustrations.
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UNLIKE DNA, RNA… • Contains the sugar ribose instead of deoxyribose. • Single-strandedinstead of double stranded. • Containsuracil in place of thymine.
Three Main Types of RNA • Messenger RNA (mRNA) - Carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell (serve as “messenger”) • Ribosomal RNA (rRNA) – Makes up the major part of ribosomes, which is where proteins are made. • Transfer RNA (tRNA) - Transfers amino acids to ribosomes during protein synthesis
Remember Proteins? • They are BIOMOLECULES! • Proteins are made up of a chain of amino acid monomers and they are formed at the ribosomes! • Proteins can be enzymes, which catalyze and regulate chemical reactions. Proteins also make up our structure!
2 Steps to Make a Protein: 1. Transcription • DNA → RNA 2. Translation • RNA → Protein (Chain of amino acids)
TRANSCRIPTION NUCLEUS
First part of protein synthesis:Transcription • Transcription = DNA RNA • Takes place in the nucleus. • Two enzymes help: 1. Helicase - separates DNA helix 2. RNA polymerase – brings RNA nucleotides over to be synthesized into mRNA • Template strand: the side of DNA that will be used to create an mRNA strand
Transcribing the Genetic Code: • The genetic code is read three letters at a time, called “codons” on the mRNA strand • The genetic code (language) from DNA is transcribed into mRNA during transcription. Each codon will have a special amino acid that matches it!
Transcription Animations • http://www.ncc.gmu.edu/dna/mRNAanim.htm • http://www.johnkyrk.com/DNAtranscription.html • http://www-class.unl.edu/biochem/gp2/m_biology/animation/gene/gene_a2.html • http://207.207.4.198/pub/flash/26/transmenu_s.swf (very good but need to skip some parts)
IN YOUR OWN WORDS… • In your notebook, below the drawing- Describe the purpose and process of transcription. Use these stems! The purpose of transcription is…. The process of transcription is …
After Transcription… • The mRNA leaves the nucleus and travels to the ribosomes in the cytoplasm. • The ribosomes are the only place to BUILD proteins.
TRANSLATION RIBOSOMES IN THE CYTOPLASM
Second part of protein synthesis: Translation • Translation = mRNA protein • Takes place at the ribosomes • mRNA that was transcribed leaves the nucleus and attaches to the ribosome. • One codon at a time is matched to a tRNA “anticodon”. • When tRNA sits down at it’s matching codon, the amino acid it carries is dropped off and bonded to the protein chain by peptide bonds. NOW YOU HAVE A PROTEIN!
Translation (DRAW THIS) ANTICODON CODON EXAMPLE: The tRNA molecule for methionine (an amino acid) has the “anticodon” UAC which matches to the “codon” AUG.
An amino acid chart is used to find out which amino acid joins the protein chain next! ALWAYS read the mRNA codon!
Translation Animations • http://207.207.4.198/pub/flash/26/transmenu_s.swf (very good animation!)
IN YOUR OWN WORDS… • In your notebook, below the drawing- Describe the purpose and process of translation. Use these stems! The purpose of translation is…. The process of translation is …
First part of protein synthesis:_______________________________ • ________________ = ____________ ______________ • Takes place in the _____________. • Two enzymes help: 1. __________ - separates DNA helix 2. __________________– brings RNA nucleotides over to be synthesized into mRNA • _________________: the side of DNA that will be used to create an mRNA strand • The genetic code is read _________________________ called ___________on the mRNA strand • The genetic code (language) from DNA is transcribed into mRNA during ______________________.
Second part of protein synthesis:________________________ • __________________ = ______________ ____________ • Takes place at the _____________________. • mRNA that was transcribed ___________________________ and attaches to a ____________________. • One codon at a time is matched to a ___________________. • When tRNA sits down at it’s matching codon, the ____________________it carries is ___________________ and bonded to the protein chain by _________________. NOW YOU HAVE A _________________________!