RNA and Protein Synthesis Chapter 13 Why do

RNA and Protein Synthesis Chapter 13

Why do we need RNA? § DNA cannot leave the nucleus § DNA gets transcribe into Messenger RNA (m. RNA) § Once edited, m. RNA can leave the nucleus as a single strand

Similarities and differences between DNA and RNA § http: //www. usask. ca/education/coursewor k/mcvittiej/bio 30 unit 1/overheads/1. 23. htm

Similarities and differences between DNA and RNA

Conection between DNA and Protein § DNA defines the genotype (genetic makeup) § Proteins determine the phenotype (specific trait) § Each gene codes for one protein (polypeptide) http: //www. pbs. org/wgbh/nova/body/rnai. ht ml

DNA to Protein Connection § Geneticists Beadle and Tatum studied mutant strain of orange mold § This strain was missing a necessary enzyme for mold to grow § Each mutant strain was defective in a single gene § One gene-on enzyme hypothesis § More accurate – One gene one polypeptide http: //www. youtube. com/watch? v=v. Irrt. M 47 Wio 9: 33

Life is orchestrated by Proteins § Combinations of 20 different amino acids linked in long chains § Function is determined by amino acid sequence § Amino acid sequence is determined by DNA sequence § Used for enzymes, hair, muscles, cell parts

Amino Acids Linked § Amino Acids Link Together to Form a Protein (Polypeptide)

Protein Synthesis § DNA → RNA → Protein (polypeptide) § This happens in two main steps: § Transcription § RNA synthesis § RNA editing § Translation

Transcription-translation animations § http: //www. hhmi. org/biointeractive/dna/ani mations. html § http: //www. youtube. com/watch? v=Yx. Ld. BN Axq. Kg&src_vid=T 1 DVt. Da. KEo&feature=iv&annotation_id=annotat ion_561613 § http: //www. youtube. com/watch? v=T 1 DVt. Da. KEo § http: //www. youtube. com/watch? v=1 fi. Jupfb Spg

Information is sent from the Nucleus to ribosome where protein is made

Outline of making Protein § Directions on DNA § DNA opens up and messenger RNA (m. RNA) copies message § m. RNA is edited – some parts taken out (introns) § m. RNA goes out of nucleus to ribosome § m. RNA attaches to ribosome § Transfer RNA (t. RNA) picks up an amino acid § t. RNA attaches to m. RNA matching complementary base pairs at opposite end from amino acid § Amino acid is attached to other amino acids held by the ribosome to make a chain of protein § When protein completely built unattached from ribosome

1. A sequence of nucleotides In DNA (a gene) is transcribed to RNA in the nucleus 2. The RNA travels to the cytoplasm where it is translated into the specific amino acid sequece of a polypeptid

A codon is a threebase "word" that codes for one amino acid. Several codons form a "sentence" that translates into a polypeptide.

Transcription players § § § DNA Messenger RNA (m. RNA) RNA polymerase

Transcription

m. RNA editing

Translation players § § m. RNA Transfer RNA Ribosome Ribosomal RNA

Translation

Transcription-translation animations § http: //www. hhmi. org/biointeractive/dna/ani mations. html § http: //www. youtube. com/watch? v=Yx. Ld. BN Axq. Kg&src_vid=T 1 DVt. Da. KEo&feature=iv&annotation_id=annotat ion_561613 § http: //www. youtube. com/watch? v=T 1 DVt. Da. KEo § http: //www. youtube. com/watch? v=1 fi. Jupfb Spg

§ Protein making analogy short movie http: //www. pbs. org/wgbh/nova/sciencenow/ 3210/02. html 00: 54 – 03: 20

What are Mutations § Any change in the nucleotide sequence of DNA § Two types of point mutations (involving only one or a few nucleotides) § Base substitutions § Base deletions or insertions

Types of mutations

§ Bill Nye Genetics greatest discoveries § http: //www. youtube. com/watch? v=v. Irrt. M 4 7 Wio § http: //school. discoveryeducation. com/tea chersguides/pdf/lifescience/ds/greatest_d iscoveries_nye_genetics. pdf

From DNA to Protein