RNA and Protein Synthesis Chapter 13

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

Similarities and differences between DNA and RNA  k/mcvittiej/bio30unit1/overheads/1.23.htm k/mcvittiej/bio30unit1/overheads/1.23.htm k/mcvittiej/bio30unit1/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) 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 9:33

Life is orchestrated by Proteins 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  mations.html mations.html mations.html  AxqKg&src_vid=T1DV- tDaKEo&feature=iv&annotation_id=annotat ion_ AxqKg&src_vid=T1DV- tDaKEo&feature=iv&annotation_id=annotat ion_ AxqKg&src_vid=T1DV- tDaKEo&feature=iv&annotation_id=annotat ion_  tDaKEo tDaKEo tDaKEo  Spg Spg 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 (mRNA) copies message  mRNA is edited – some parts taken out (introns)  mRNA goes out of nucleus to ribosome  mRNA attaches to ribosome  Transfer RNA (tRNA) picks up an amino acid  tRNA attaches to mRNA 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 three- base "word" that codes for one amino acid. Several codons form a "sentence" that translates into a polypeptide.

Transcription players  DNA  Messenger RNA (mRNA)  RNA polymerase

Transcription

mRNA editing

Translation players  mRNA  Transfer RNA  Ribosome  Ribosomal RNA

Translation

Transcription-translation animations  mations.html mations.html mations.html  AxqKg&src_vid=T1DV- tDaKEo&feature=iv&annotation_id=annotat ion_ AxqKg&src_vid=T1DV- tDaKEo&feature=iv&annotation_id=annotat ion_ AxqKg&src_vid=T1DV- tDaKEo&feature=iv&annotation_id=annotat ion_  tDaKEo tDaKEo tDaKEo  Spg Spg Spg

 Protein making analogy short movie /02.html /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 Bill Nye Genetics greatest discoveries Bill Nye Genetics greatest discoveries  7Wio 7Wio 7Wio  chersguides/pdf/lifescience/ds/greatest_d iscoveries_nye_genetics.pdf chersguides/pdf/lifescience/ds/greatest_d iscoveries_nye_genetics.pdf chersguides/pdf/lifescience/ds/greatest_d iscoveries_nye_genetics.pdf

From DNA to Protein