DNA, RNA, and Protein Synthesis http://faculty.uca.edu/~johnc/mbi1440.htm DNA, RNA, and Protein Synthesis http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/mRNA.gif

Structure of DNA DNA – base pairs carry the genetic code for the sequence of the amino acids Section 12-1 Nucleotide Hydrogen bonds Sugar-phosphate backbone Key Adenine (A) Thymine (T) Cytosine (C) Guanine (G)

Nucleotides in the DNA strand carry the code for proteins Image by: Riedell

Nitrogen bases =“Steps of ladder” Purines (2 rings) Phosphate group G C Pyrimidines (1 ring) Deoxyribose sugar T © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

Nitrogen bases =“Steps of ladder” ADENINE Phosphate group G GUANINE C CYTOSINE Deoxyribose sugar THYMINE T © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

CHARGAFF’S RULES A = T G = C _________ _________ _________ _________ At time no one knew why… now we know its because Adenine always bonds across with____________ Guanine always bonds across with ____________ THYMINE CYTOSINE Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif

RNA and PROTEIN SYNTHESIS DNA is safely stored in the nucleus. mRNA (messenger RNA) brings a copy of the code out to the cytoplasm. RNA and PROTEIN SYNTHESIS © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

Transcription - Making a copy of the DNA code Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNA polymerase DNA RNA Enzyme called RNA polymerase separates strands of DNA, then uses one strand as a template to assemble an mRNA copy. mRNA will carry the “script” out of the nucleus to the cytoplasm

RNA- the Other Nucleic Acid Also made of nucleotides Sugar is ribose instead of deoxyribose. RNA is single stranded, instead of doubled stranded. Contains uracil instead of thymine. http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg

Replication Done only by DNA Nucleus of the eukaryotic cells Noun The action of copying or reproducing something. A copy. Synonyms reply - rejoinder - answer - response - replica - copy Done only by DNA Nucleus of the eukaryotic cells

Transcription Noun A written or printed representation of something. The action or process of transcribing something. Synonyms transcript – re-write Done by the mRNA Nucleus of an eukaryotic cell Contains the codon

Translation Noun The process of translating words or text from one language into another. A written or spoken rendering of the meaning of a word or system. Synonyms rendering - rendition – interpretation Done by tRNA Contains the anticodon Contains the amino acid

MASTER PLAN DNA stays safe in nucleus © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved TRANSCRIPTION (DNA→ RNA) & PROCESSING (remove interons) takes place in nucleus TRANSLATION (RNA→ proteins) takes place on ribosomes in cytoplasm “Blueprints” of master plan are carried to building site http://www.home-improvement-resource.com/images/architect.jpg

Translation - Translating the base pair codes into an amino acid sequence mRNA – the copy of the code sequence of base pairs tRNA – carries the amino acid to the ribosome as coded for in the mRNA – codons code for specific amino acids.

EACH tRNA carries only one kind of _____________ amino acid ANTICODON on tRNA matches up with ________ on mRNA CODON Images modified from © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

HOW CAN JUST 4 BASES GIVE DIRECTIONS TO MAKE 20 AMINO ACIDS? Message is read in groups of 3 = _________ UCGCACGGU UCG-CAC-GGU CODON Serine - Histidine - Glycine Codons represent different amino acids

AUG The mRNA Code 64 possible codons Some amino acids have more than one codon. START= _______ 3 codons for _____ AUG STOP

Translation Translating the base pair codes into an amino acid sequence

Translation (continued)

Summary of protein synthesis DNA strand in nucleus Occurs in the nucleus RNA message copied from DNA mRNA moves out to cytoplasm Occurs in the cytoplasm at the ribosome

A graphic to show you translation to sequence the protein ribosome codon carries a specific amino acid depending upon its code

What is Gel Electrophoresis? Gel electrophoresis is a widely used technique for separating electrically charged molecules. It is a central technique in molecular biology and genetics laboratories, because it lets researchers separate and purify the nucleic acids DNA and RNA and proteins, so they can be studied individually. Gel electrophoresis is often followed by staining or blotting procedures used to identify the separated molecules. Read more: http://www.answers.com/topic/gel-electrophoresis#ixzz1pgFnADfN

 Gel Electrophoresis

 Gel Electrophoresis

Test February 14/15 Please Study!