DNA, RNA, and Protein Synthesis Subtitle

10.1 Discovery of DNA

10.2 DNA Structure LEARNING TARGETS I will be able to: Evaluate the contributions of Franklin and Wilkins in helping Watson and Crick discover DNA’s double helix structure Describe the 3 parts of a nucleotide Relate the role of base-pairing rules to the structure of DNA

Rosalind Franklin

Rosalind Franklin Took the first ever picture of DNA using x-ray diffraction This information was then used by Watson and Crick

James Watson and Francis Crick (1953) Watson (American) & Crick (British) 2. Watson and Crick developed the structure of DNA as a double helix Looks like a twisting staircase

James Watson and Francis Crick (1953) Looks like a twisting staircase a. The shape of DNA is a double helix

DNA Nucleotides Nucleotides are the building blocks (monomers) of ………? A. proteins B. lipids C. carbohydrates D. nucleic acids

DNA Nucleotides Nucleotides are the building blocks (monomers) of ………? NUCLEIC ACIDS!!!!!!!!!!! If answered correctly… https://www.youtube.com/watch?v =3GwjfUFyY6M

DNA Nucleotides (3 parts) Made up of 3 parts: Phosphate group

DNA Nucleotides (3 parts) Made up of 3 parts: Phosphate group Deoxyribose sugar

DNA Nucleotides (3 parts) Made up of 3 parts: Phosphate group Deoxyribose sugar Nitrogen base

DNA Nucleotides (3 parts) Sugar and phosphate groups are identical in all nucleotides Bases are different

DNA Nucleotides (3 parts) Deoxyribose sugar and phosphate make up the “backbone” of DNA Sides of the ladder (yellow)

DNA Nucleotides (3 parts) Nitrogen bases make up the middle of DNA Rungs of the ladder (multicolor)

Nitrogenous Bases (4 types) T - Thymine C - Cytosine

Nitrogenous Bases (4 types) G - Guanine A - Adenine

Erwin Chargaff (1949) American biochemist Noticed that amount of A = amount of T Amount of C = amount of G

Base-Pairing Rules C always pairs with G A always pairs with T These are complementary bases connected by hydrogen bonds

Base-Pairing Rules

Base-Pairing Rules

10.3 DNA Replication

10.3 DNA Replication LEARNING TARGETS I will be able to: Summarize the process of DNA replication Identify the role of enzymes if the replication of DNA Describe how complementary base pairing guides DNA replication Describe mutations that occur during DNA replication

10.3 DNA Replication https://www.youtube.com/watch?v=dKubyIRiN84

DNA Replication Amount of DNA is doubled in preparation for cell division

DNA Replication – 3 Steps One DNA strand is separated into two strands a. Helicase – enzyme that separate DNA strands

DNA Replication – 3 Steps Almost like using a zipper on a jacket b. replication fork - Y shaped region where strands are being separated

DNA Replication – 3 Steps Complementary bases are added to new strands What gets added to A? What gets added to C?

DNA Replication – 3 Steps DNA polymerase – enzyme that adds nucleotides to new strands

DNA Replication – 3 Steps d. DNA has 5’ end and 3’ end e. DNA polymerase always works from 5’ to 3’

DNA Replication – 3 Steps f. Leading strand – where DNA polymerase works toward split in DNA g. Lagging strand – where DNA polymerase works away from split in DNA

DNA Replication – 3 Steps DNA polymerase falls off Forms two new strands

Mutations Mutation – change in nucleotide sequence of DNA

Mutations Addition – nucleotide is added to the sequence

Mutations Deletion – one nucleotide is removed from sequence

Mutations Substitution – one nucleotide is exchanged for another

What is the enzyme responsible for splitting DNA apart? Front door left: DNA polymerase Front door right: RNA polymerase Back right corner: helicase Back left corner: peptase

What is the mutation called when you add a nucleotide (letter? Front door left: addition Front door right: deletion Back right corner: substitution Back left corner: transfiguration

10.4 Protein Synthesis

10.4 Protein Synthesis LEARNING TARGETS: I will be able to: Outline the flow of genetic information from DNA to protein Compare the structures of DNA and RNA Summarize the process of transcription Compare the role of mRNA, tRNA, and rRNA Identify the importance of learning about the human genome

10.4 Protein Synthesis https://www.youtube.com/watch?v=41_Ne5mS2ls

Protein Synthesis Overview Consists of transcription and translation Transcription – DNA  mRNA (happens in nucleus)

Protein Synthesis Overview Consists of transcription and translation Translation – mRNA  amino acids (happens on ribosome)

RNA Structure single helix Ribose sugar, not deoxyribose sugar Has uracil (U) instead of thymine (T) U-A and C-G base pairing

2 Types of RNA mRNA – messenger RNA Takes info from DNA in nucleus to ribosome in cytoplasm

2 Types of RNA tRNA – transfer RNA Transfers amino acids during translation Aka “anticodon”

Transcription Steps RNA polymerase attaches to START

Transcription Steps DNA unwinds

Transcription Steps RNA polymerase adds complementary bases Complementary mRNA is formed!

Transcription Steps #1 on back of notes DNA: TAC CGT ATC mRNA: ?????

Transcription Steps #1 on back of notes DNA: TAC CGT ATC mRNA: AUG GCA UAG

Genetic Code Explains how a sequence of bases creates a specific amino acid

Genetic Code 3 nucleotides code for a specific amino acid Codon – a 3 nucleotide sequence in mRNA that codes for an amino acid

Codon Table

Codon Table

Translation Steps mRNA attaches to rRNA of ribosome

Translation Steps 2. tRNA brings amino acids to ribosome Don’t forget that amino acids are the building blocks of proteins! Anticodon on tRNA starts the translation process

Translation Steps Codon = CGA Anticodon = GCU

Translation Steps Amino acids form bond together tRNA leaves

Translation Steps STOP codon reached and translation stops Ribosome leaves and protein forms

Translation Steps #3 on back of notes mRNA = AUG GCA UAG Amino acids = ??????

Translation Steps #3 on back of notes mRNA = AUG GCA UAG Amino acids = start alanine stop

Translation Steps #5 on back of notes mRNA = AUG GCA UAG Anticodons = ?????????

Translation Steps #5 on back of notes mRNA = AUG GCA UAG Anticodons = UAC CGU AUC

Translation Steps https://www.youtube.com/watch?v=B6O6uRb1D38

Translation Steps If DNA strand = TAC CGA GAT ATT What would be the complementary mRNA strand? What would be the amino acids formed? What would be the anti-codons?

Human Genome We’ve figured out the order of 3.2 billion base pairs in the 23 human chromosomes!!!!!!!!!!!!!! About 30,000 genes in human genome Can help find genes responsible for specific diseases