Gene Expression DNA RNA Protein Transcription Translation What is the language of DNA?

Gene ExpressionDNA RNA Protein

Transcription TranslationWhat is the language of DNA?

DNA Double Helix- Deoxyribonucleic acid“Genetic material of Life” “Twisted” ladder

Nucleotides- Building Blocks

Nucleotide- Base, sugar, phosphate group

Nitrogen Bases

• Purine, • Adenine, • Guanine,

• Pyrimidine. Thymine,• Cytosine• “Y”- pyrimidine

Complimentary Base pairs

• Adenine - -Thymine• (A T & T) - two• Cytosine - - - Guanine

• Combine by double / triple bonds.

• (-) = Hydrogen bonds

DNA Double Helix

DNA ReplicationDNA replication (chromosomes replicated during S phase) is SEMI-CONSERVATIVE.

http://www.youtube.com/watch?v=AGUuX4PGlCc

What is semi-conservative? MatchOriginal two strands of DNA (at left)- Which figure below represents semi- conservative copying?

A

C

B

D

• Replicated DNA contains ½ one Old and ½ one New – why? Fig. 11-9 Iguana, 9-9 Manatee

• Reduce mistakes and is faster.

Replication

DNA Replication http://www.johnkyrk.com/DNAreplication.html Simple Best DNA- http://www.lewport.wnyric.org/jwanamaker/animations.htm

DNA Replication

• DNA is “unzipped” by DNA Helicase (Helix is shape of DNA = spiral)

DNA Replication New bases added by DNA Polymerase. 5’ to 3’,

direction. (like one end to other).

DNA Replication

Give complimentary side of this sequence

• DNA below• TAC/ACC/TAG/CTT/TTGACGGGGAACCCCATT• ATG/TGG/ATC/GAAAACTGCCCCTTGGGGTAA• DNA is proofread and errors are only 1 in

every Billion nucleotides!

Objectives• Compare The structure of RNA with that of

DNA.

• Summarize Transcription- DNARNA

Gene Expression/ Central Dogma for Molecular Biology• DNA(Transcription) RNA (Translation)

Proteins

Decoding the Information in DNA

• Traits- eye color, hair color determined by proteins, built according to instructions coded in DNA.

• Proteins however, not built directly from DNA but from Ribonucleic acid.

• Ribonucleic acid (RNA) nucleic acid similar to DNA.

DNARNA- Transcription• DNA is like a book, Chapters are

Chromosomes, Sections are Genes• DNA stays protected in nucleus• ** (Do not want to damage)**• RNA is copied from shorter sequence

of DNA, leaves nucleus• RNA is Working copy of DNA- leaves

nucleus.

Transcription- (Nucleus)

Removal of introns After Transcription- mRNA leaving is called exons = GENE

3 Types of RNA

Ribonucleic Acid

Comparing DNA/RNA- 3 differences

DNA• Two strands• Deoxyribose Sugar• Thymine

A- - TC ---G

RNA• Single strand• Ribose Sugar• Uracil• NO Thymine• A-U• C-G

Transcription- (Nucleus)• RECALL- DNA/DNA• TAC/ACC/TAG/CTT/TTGACGGGGAACCCCATT• ATG/TGG/ATC/GAA/AACTGCCCCTTGGGGTAA

• Given DNA sequence below• What is the complimentary mRNA? Recall NO

Thymine!• TAC/ACC/TAG/CTT/TTG/ACG/GGG/AAC/CCC/ATT• AUG/UGG/AUC/GAA/AAC/UGCCCCUUGGGGUAA

Objectives

• Outline The major steps of translation.

• Relate Codons to the sequence of amino acids that results after translation.

• Discuss The evolutionary significance of the genetic code.

Translation: Assembling Proteins

Section 1 From Genes to ProteinsChapter 10

Translation-(Cytoplasm) RNA Proteins

• RNA Code is read • CODON – “Code on” mRNA- messenger

RNA• CODON = 3 Bases ON- results in Amino

Acid• Chain of Amino Acids makes protein

(polypeptide)

Translation RNA Protein

• UGUUAUAUCGAAAACUGCCCCUUGGGGUAA• Read every 3 bases= CODON• UGU/UAU/AUC/GAA/AAC/UGC/CCC/UUG/GGG/UAA

Codon- sheet• Why read every 3 bases? • Codon combinations must cover 20 different

AA- Amino Acids • 41 = 4• 42 = 16• 43 = 64 CHECK!• Results in 64 combinations• Start sequence AUG.• End sequence UAA, UAG, UGA.

Codes in mRNA

Translation RNA Protein

• UGUUAUAUCGAAAACUGCCCCUUGGGGUAA• Read every 3 bases= CODON• UGU/UAU/AUC/GAA/AAC/UGC/CCC/UUG/GGG/UAA

Amino Acids

• Amino acids can be• Polar/Non Polar• Hydrophobic/Hydrophilic • Acidic/Basic• Depending on sequence this will make a

shape = GENE

Translation: Forming the First Peptide Bond

Section 1 From Genes to ProteinsChapter 10

tRNA

• tRNA- Transfer RNA, “transfers” the Amino Acid to the ribosome to make protein

• tRNA is complimentary to mRNA, “lock & key” fit. Every codon has only one Anticodon.

• AUG/CAA- Codon• UAC/GUU- Anticodon- specific AA• Met-Glu- Amino acids

Translation: Assembling Proteins

Section 1 From Genes to ProteinsChapter 10

Video showing transcription/translation

• https://www.youtube.com/watch?v=erOP76_qLWA

Mutations

Major Types of Mutations

Mutation- Change in sequence of the DNA- deoxyribonucleic acid

• A. Chromosomal- whole, parts added or deleted, sections translocated to other chromosomes.

• B. Gene- –1. Point–2. Frameshift.

Somatic-affects individual- EX. skin cancer.Genetic- affects sperm or egg affects

offspring.

Gene mutations1. Point mutation- affects onenucleotide fig. 11-7 p. 230 Iguana

• p. 219 Manatee • Ex. • TAC GTT CCA, change TAC GTA CCA, • If this makes different codon

(language of genetics), = new amino acid

Point mutation analogy

• The dog ran out the box• Point mutation Change D and C.• The Cog ran out the box.

Frame shift mutationB. Frame shift mutation- removal of a

base(s) or insertion of a segment, results in different “reading” of gene. CODON= 3 bases.

• TAC GTT CCA- original sequence. T(AC G)TT CCA remove first (T) ACG TTC CA…. TA)C GTT CCAinsert T TTA CGT TCC A

Frame shift mutation analogy

• The dog ran out the box• TTh edo gra nou tth ebo x. ADDITION of a T• Heg ogr ano uth heb ox DELETION of a T

Genetic Code- Evolutionary significance

• The code AUG/CCC/, whether in human or oak tree, or mosquito, etc.. makes same amino acids….Met--Pro

• This shows relatedness of all living organisms.

How can a glow in the dark gene from Jellyfish work in a pig?

• DNA is a code like words if it fits and makes sense, then it can be used.

• The dog ran down the street.

• The cat ate a bird.

• The dog ate a bird. Still makes “sense”.