RNA and Protein Synthesis CTE: Agriculture and Natural Resources: C5.3 Understand various cell actions, such as osmosis and cell division. C5.4 Compare and contrast plant and animal cells, bacteria, and viruses. California State Science Standards: Cell Biology ü d. Students know the central dogma of molecular biology outlines the flow of information from transcription of ribonucleic acid (RNA) in the nucleus to translation of proteins on ribosomes in the cytoplasm. ü Genes are a set of instructions encoded in the DNA sequence of each organism that specify the sequence of amino acids in proteins characteristic of that organism. As a basis for understanding this concept: ü Students know how to apply the genetic coding rules to predict the sequence of amino acids from a sequence of codons in RNA.
Let s think a bit
Central Dogma
Vocabulary Messenger RNA- (mrna) RNA molecule that carries copies of instruction for the assembly of amino acids into proteins from DNA to the rest of the cell. Proteins are made from that are assembled using instructions stored in that are copied and carried to the assembly site by.
Vocabulary Transcription- Process in which part of the nucleotide sequence of DNA is rewritten into a complementary sequence in RNA. During a sequence of DNA is so that RNA can use it RNA RNA polymerase DNA
Vocabulary Ribosomal RNA- (rrna) Type of RNA that is part of the structure of ribosomes. Ribosomes are made of also called and proteins. Ribosomes are located in the cytoplasm. Where are ribosomes in the cell?
Vocabulary Transfer RNA (trna) Type of RNA molecule that transfers amino acids to ribosomes during protein synthesis. Amino acids are to ribosomes during protein synthesis by ( ) a type of RNA molecule.
Vocabulary RNA polymerase- Enzyme similar to DNA polymerase that catalysis the transcription of RNA from a DNA template by binding to a promoter. During transcription, the enzyme binds to DNA, separating the strands, and the DNA strand to a complementary RNA strand.
Chapter 10 Notes The Structure of RNA ü ü It consists of long chains of nucleotides, like DNA There are four main differences from DNA
The Difference Between RNA & DNA RNA 1. Contains the sugar Ribose 2. Nitrogenous Base Uracil 3. Single Stranded 4. Short strands DNA 1. Contains the sugar Deoxyribose 2. Nitrogenous Base Thymine 3. Double Stranded 4. Long strands
Partner Recap: RNA Types a. Main function is protein synthesis b. There are three main types of RNA 1)Messenger RNA (mrna) 2)Ribosomal RNA (rrna) 3)Transfer RNA (trna):
Mind Moo-ver 1. What are the 3 types of RNA and what does each type do?
Review Transcription v Transcription: Process in which the DNA nucleotide sequence is copied into a complementary RNA sequence
Transcription Steps v Steps: 1. RNA Polymerase binds to the promoter and DNA strand unwinds and separates 1. Promoter: specific nucleotide sequence 2. RNA polymerase adds free RNA nucleotides creating an mrna 3. RNA reaches a the terminator, a specific sequence of nucleotides that marks the end of the gene
Translation of RNA Objective: I will understand transcription and translation enough to be able to transcribe DNA into a code and translate that code into a secret message.
Part 2 Vocabulary Codon- Three-nucleotide sequence on messenger RNA that codes for a single amino acid. An mrna strand is divided into threenucleotide sequences called that have complementary on trna that code for a specific amino acid. Anticodon (B Reads) Group of three bases on a trna molecule that are complementary to an mrna codon. U C A A U
Vocabulary Translation- Decoding of mrna message into a polypeptide chain. Amino acid Anticodon trna Where is this happening? codon mrna
Translation Notes 2. There are four main steps to translation a. mrna must be transcribed from DNA in the nucleus and released into the cytoplasm b. mrna attaches to the ribosome at a start codon (AUG) c. As each mrna codon goes through the ribosome, the proper amino acid is attached using the genetic code 2)The Genetic Code is a universal language for reading mrna 3)tRNA molecules have amino acids attached to one end and three unpaired bases at the other 4)The three bases, called the anticodon, are complementary of the mrna codon 5)The codons fit in place
The Process Messenger RNA Messenger RNA is transcribed in the nucleus. Transfer RNA The mrna then enters the cytoplasm and attaches to a ribosome. Translation begins at AUG, the start codon. Each transfer RNA has an anticodon whose bases are complementary to a codon on the mrna strand. The ribosome positions the start codon to attract its anticodon, which is part of the trna that binds methionine. The ribosome also binds the next codon and its anticodon.
The Polypeptide Assembly Line The ribosome joins the two amino acids methionine and phenylalanine and breaks the bond between methionine and its trna. The trna floats away, allowing the ribosome to bind to another trna. The ribosome moves along the mrna, binding new trna molecules and amino acids. Completing the Polypeptide The process continues until the ribosome reaches one of the three stop codons. The result is a growing polypeptide chain.
Partner Time! So if mrna strand reads What amino acid is coded for 1. (example) AAA (Answer) 2. CUG 3. GCA 4. UUU 5. UGA
c. Polypeptide chain grows until ribosome reaches a stop codon on the mrna 1) It releases the mrna, completing translation 2) This protein molecule can range from 50 to 3,000 amino acids
Concept Map RNA can be Messenger RNA Ribosomal RNA Transfer RNA also called which functions to also called which functions to also called which functions to mrna Carry Instructions rrna Combine with Proteins trna Bring Amino acids to ribosome from to to make up DNA Ribosome Ribosomes
Review What is the Central Dogma of molecular biology? Where does transcription take place? Where does translation take place? What would happen if mrna transcribed the DNA strand incorrectly?