chapter 11.1

CHAPTER 11.1CHAPTER 11.1

GENES ARE MADE OF DNAGENES ARE MADE OF DNA

What is in your GENES?What is in your GENES?

No not that kind!No not that kind!

These kind of genes!These kind of genes!

GRIFFITHGRIFFITH’’S S ““TRANSFORMING TRANSFORMING FACTORFACTOR”” IS THE GENETIC IS THE GENETIC

MATERIALMATERIAL Frederick Griffith proved that a Frederick Griffith proved that a

substance in one strain of bacteria substance in one strain of bacteria causes a change in another straincauses a change in another strain

FIGURE 11.1FIGURE 11.1

AVERY SHOWS DNA IS THE AVERY SHOWS DNA IS THE TRANSFORMING FACTORTRANSFORMING FACTOR

Oswald Avery, Alfred Hershey, and Oswald Avery, Alfred Hershey, and Martha Chase took GriffithMartha Chase took Griffith’’s s experiment one step further experiment one step further

Did experiments with viruses Did experiments with viruses Concluded that DNA is the genetic Concluded that DNA is the genetic

material of the cellmaterial of the cell

VIRUS EXPERIMENTS PROVIDE VIRUS EXPERIMENTS PROVIDE MORE EVIDENCEMORE EVIDENCE

A virus consists of a package of A virus consists of a package of nucleic acid in a protein coatnucleic acid in a protein coat

Bacteriophage-Bacteriophage- a virus that infect a virus that infect bacteriabacteria

VIRUSVIRUS

Figure 11-4Figure 11-4

DNADNA’’S STRUCTURES STRUCTUREDNADNA’’S STRUCTURES STRUCTURE

1950 Rosalind Franklin and Maurice 1950 Rosalind Franklin and Maurice Wilkins produced photographs of DNA Wilkins produced photographs of DNA using x-ray crystallographyusing x-ray crystallography

1950 Rosalind Franklin and Maurice 1950 Rosalind Franklin and Maurice Wilkins produced photographs of DNA Wilkins produced photographs of DNA using x-ray crystallographyusing x-ray crystallography

Erwin Chargaff- 1952Erwin Chargaff- 1952

Observed that the number of Observed that the number of adenine equals the number of adenine equals the number of thymine .thymine .

Observed that the number of Observed that the number of guanine equals the number of guanine equals the number of cytosine.cytosine.

DOUBLE HELIXDOUBLE HELIXDOUBLE HELIXDOUBLE HELIX

In 1953 James Watson and Francis Crick In 1953 James Watson and Francis Crick looked at the photographs and with looked at the photographs and with Chargaff’s discovery gave DNA a shape Chargaff’s discovery gave DNA a shape of a double helixof a double helix

In 1953 James Watson and Francis Crick In 1953 James Watson and Francis Crick looked at the photographs and with looked at the photographs and with Chargaff’s discovery gave DNA a shape Chargaff’s discovery gave DNA a shape of a double helixof a double helix

DOUBLE HELIXDOUBLE HELIXDOUBLE HELIXDOUBLE HELIX

Double Helix-Double Helix- twisting shape twisting shape Hypothesized that the strands Hypothesized that the strands

were connected by hydrogen were connected by hydrogen bondsbonds

Double Helix-Double Helix- twisting shape twisting shape Hypothesized that the strands Hypothesized that the strands

were connected by hydrogen were connected by hydrogen bondsbonds

CLASS WORKCLASS WORK

Make a list of at least four of the Make a list of at least four of the scientists we discussed today and scientists we discussed today and discuss their contribution to the discuss their contribution to the discovery of DNA.discovery of DNA.

CHAPTER 11.2CHAPTER 11.2NUCLEIC ACIDS STORE NUCLEIC ACIDS STORE INFORMATION IN THEIR INFORMATION IN THEIR

SEQUENCE OF CHEMICAL SEQUENCE OF CHEMICAL UNITSUNITS

THE BUILDING BLOCKS OF THE BUILDING BLOCKS OF DNADNA

DNA-DNA- deoxyribonucleic acid, heritable deoxyribonucleic acid, heritable genetic information of an organismgenetic information of an organism

Polymer built from monomersPolymer built from monomersNucleotides-Nucleotides- monomers of DNA, monomers of DNA,

building blocks, contain three partsbuilding blocks, contain three parts

NUCLEOTIDESNUCLEOTIDES

1) A ring shaped sugar called 1) A ring shaped sugar called deoxyribosedeoxyribose

2) A phosphate group2) A phosphate group3) A nitrogenous base3) A nitrogenous base

NITROGENOUS BASENITROGENOUS BASE

Divided into two groupsDivided into two groupsPyrimidines-Pyrimidines- single ring structures single ring structuresPurines-Purines- double ring structures double ring structures

DNA STRANDSDNA STRANDS

Nucleotides are joined together by Nucleotides are joined together by covalent bonds between the sugar and covalent bonds between the sugar and phosphatephosphate

COMPLEMENTARY BASE COMPLEMENTARY BASE PAIRSPAIRS

Adenine (A) bonds to Thymine (T)Adenine (A) bonds to Thymine (T)Guanine (G) bonds to Cytosine (C)Guanine (G) bonds to Cytosine (C)EXAMPLE:EXAMPLE:AAT GCT ATGAAT GCT ATGTTA CGA TAC TTA CGA TAC

PRACTICEPRACTICE

1) AAT GGC TAT1) AAT GGC TAT2) CAT GAT TAC2) CAT GAT TAC3) CCG TTA CCA3) CCG TTA CCA4) GCG ATA GAC4) GCG ATA GAC5) CAG TCA GCA5) CAG TCA GCA

THE TEMPLATE MECHANISMTHE TEMPLATE MECHANISM

When a cell divides a complete new set When a cell divides a complete new set of genetic instructions is madeof genetic instructions is made


DNA Replication-DNA Replication- the process of the process of copying the DNA moleculecopying the DNA molecule

Enzymes Involved in Enzymes Involved in ReplicationReplication

DNA Helicase- unzips DNA, breaks DNA Helicase- unzips DNA, breaks the Hydrogen bonds between the the Hydrogen bonds between the base pairs in order to create origin of base pairs in order to create origin of replicationreplication

REPLICATION OF THE REPLICATION OF THE DOUBLE HELIXDOUBLE HELIX

DNA Polymerase-DNA Polymerase- makes the covalent makes the covalent bonds between the nucleotidesbonds between the nucleotides

Class WorkClass Work

1.1. Describe how DNA replicates by Describe how DNA replicates by using a template.using a template.2.2. List the steps involved in DNA List the steps involved in DNA replication.replication.3.3. Under what circumstances is DNA Under what circumstances is DNA replicated?replicated?


1.1. What are the three parts of a What are the three parts of a nucleotide? Which parts make up the nucleotide? Which parts make up the backbone of a DNA strand?backbone of a DNA strand?2.2. List the two base pairs found in DNA. List the two base pairs found in DNA.3.3. If six bases on one strand of a DNA If six bases on one strand of a DNA double helix are AGTCGG, what are the double helix are AGTCGG, what are the six bases on the complementary section six bases on the complementary section of the other strand of DNA?of the other strand of DNA?

THE TEMPLATE THE TEMPLATE MECHANISMMECHANISM

When a cell divides a complete new set When a cell divides a complete new set of genetic instructions is madeof genetic instructions is made


DNA Replication-DNA Replication- the process of the process of copying the DNA moleculecopying the DNA molecule

REPLICATION OF THE REPLICATION OF THE DOUBLE HELIXDOUBLE HELIX

DNA Polymerase-DNA Polymerase- makes the covalent makes the covalent bonds between the nucleotidesbonds between the nucleotides


1.1. Describe how DNA replicates by Describe how DNA replicates by using a template.using a template.2.2. List the steps involved in DNA List the steps involved in DNA replication.replication.3.3. Under what circumstances is DNA Under what circumstances is DNA replicated?replicated?

CHAPTER 11.4 and CHAPTER 11.4 and 11.5 11.5

A GENE PROVIDES THE A GENE PROVIDES THE INFORMATION FOR MAKING A INFORMATION FOR MAKING A

SPECIFIC PROTEINSPECIFIC PROTEIN

ONE GENE, ONE ONE GENE, ONE POLYPEPTIDE- DonPOLYPEPTIDE- Don’’t need to t need to

writewrite George Beadle and Edward Tatum George Beadle and Edward Tatum

worked with the bread mold neurospora worked with the bread mold neurospora crassacrassa

ONE GENE, ONE ONE GENE, ONE POLYPEPTIDE- DonPOLYPEPTIDE- Don’’t need to t need to

writewrite One Gene-One Enzyme Hypothesis-One Gene-One Enzyme Hypothesis- the the

function of an individual gene is to dictate the function of an individual gene is to dictate the production of a specific enzymeproduction of a specific enzyme

Now…ONE GENE-ONE POLYPEPTIDE Now…ONE GENE-ONE POLYPEPTIDE HYPOTHESISHYPOTHESIS

INFORMATION FLOW: DNA INFORMATION FLOW: DNA TO RNA TO PROTEINTO RNA TO PROTEIN

RNA-RNA- ribonucleic acid, has a sugar or ribonucleic acid, has a sugar or ribose, base uracil, single strandedribose, base uracil, single stranded


DNADNA DeoxyriboseDeoxyribose ThymineThymine Double-StrandedDouble-Stranded

RNARNA RiboseRibose UracilUracil Single StrandedSingle Stranded


Transcription-Transcription- when DNA is when DNA is converted into single stranded converted into single stranded mRNA, in nucleusmRNA, in nucleus

mRNA moves to cytoplasm while mRNA moves to cytoplasm while DNA stays in the nucleusDNA stays in the nucleus


Translation-Translation- the nucleic acid information the nucleic acid information (RNA) is converted into amino acids, in (RNA) is converted into amino acids, in cytoplasmcytoplasm

Codon-Codon- a three-base a three-base ““wordword”” that codes for one that codes for one amino acidamino acid

Several codons form a polypeptideSeveral codons form a polypeptide

TRANSLATION: RNA TO TRANSLATION: RNA TO PROTEINPROTEIN

Transfer RNA-Transfer RNA- translates the 3 letter codon of mRNA translates the 3 letter codon of mRNA into an amino acidinto an amino acid


Anticodon-Anticodon- a triplet of bases that is complementary to a triplet of bases that is complementary to a specific mRNA sequencea specific mRNA sequence

THE TRIPLET CODETHE TRIPLET CODE

Marshall Nirenberg figured out that Marshall Nirenberg figured out that the codon UUU makes the amino acid the codon UUU makes the amino acid phenylalaninephenylalanine

CHANGE THE DNA to mRNACHANGE THE DNA to mRNA

1. TAT CAT GAT1. TAT CAT GAT 2. CCA GGG CTA2. CCA GGG CTA 3. TAC TAG TTC3. TAC TAG TTC 4. GCA ATA TTC4. GCA ATA TTC 5. GCA ATG CCT5. GCA ATG CCT

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1.1. How did Beadle and Tatum's research result How did Beadle and Tatum's research result in the "one gene–one polypeptide" hypothesis?in the "one gene–one polypeptide" hypothesis?2.2. Which molecule completes the flow of Which molecule completes the flow of information from DNA to protein?information from DNA to protein?3.3. Which amino acid is coded for by the RNA Which amino acid is coded for by the RNA sequence CUA?sequence CUA?4.4. List two ways RNA is different from DNA. List two ways RNA is different from DNA.


THERE ARE TWO MAIN THERE ARE TWO MAIN STEPS FROM GENE TO STEPS FROM GENE TO

PROTEINPROTEIN

TRANSCRIPTION: DNA TO TRANSCRIPTION: DNA TO RNARNA

3 types of RNA3 types of RNA– Messenger RNA (mRNA)Messenger RNA (mRNA)– Transfer RNA (tRNA)Transfer RNA (tRNA)– Ribosomal RNA (rRNA)Ribosomal RNA (rRNA)

Messenger RNA-Messenger RNA- an RNA molecule an RNA molecule which is transcribed (COPIED) from a which is transcribed (COPIED) from a DNA templateDNA template

RNA Polymerase-RNA Polymerase- links the RNA links the RNA nucleotides togethernucleotides together

EDITING THE RNA EDITING THE RNA MESSAGEMESSAGE

Intron-Intron- non-coding regions of DNA non-coding regions of DNA Exon-Exon- parts of a gene that will be parts of a gene that will be

translated or expressedtranslated or expressed RNA Splicing-RNA Splicing- when the introns are when the introns are

removed from the RNA before it removed from the RNA before it moves to the cytoplasmmoves to the cytoplasm


Transfer RNA-Transfer RNA- translates the 3 letter codon translates the 3 letter codon of mRNA into an amino acidof mRNA into an amino acid


Anticodon-Anticodon- a triplet of bases that is a triplet of bases that is complementary to a specific RNA complementary to a specific RNA sequencesequence

Ribosomal RNA-Ribosomal RNA- located in the ribosome located in the ribosome


1.1. What kind of nucleic acid is made What kind of nucleic acid is made during transcription?during transcription?2.2. How do introns and exons relate to How do introns and exons relate to RNA splicing?RNA splicing?3.3. List the three RNA types involved in List the three RNA types involved in transcription and translation, and transcription and translation, and describe the role of each. describe the role of each. 4.4. Briefly describe the steps of protein Briefly describe the steps of protein synthesis. synthesis.


MUTATIONS CAN CHANGE THE MUTATIONS CAN CHANGE THE MEANING OF GENESMEANING OF GENES

HOW MUTATIONS AFFECT HOW MUTATIONS AFFECT GENESGENES

Mutation-Mutation- any change in the any change in the nucleotide sequence of DNAnucleotide sequence of DNA

Two typesTwo types– Base SubstitutionBase Substitution– Base InsertionBase Insertion//DeletionDeletion

WHAT CAUSES MUTATIONS?WHAT CAUSES MUTATIONS?

Errors in DNA replicationErrors in DNA replication Mutagens-Mutagens- physical or chemical physical or chemical

agents that cause mutationsagents that cause mutations– X-raysX-rays– UV LightUV Light– SmokingSmoking

Mutations can be harmful or Mutations can be harmful or beneficialbeneficial


1.1. Explain why a base substitution is often Explain why a base substitution is often less harmful than a base deletion or less harmful than a base deletion or insertion.insertion.

2.2. Describe how a mutation could be Describe how a mutation could be helpful rather than harmful.helpful rather than harmful.

3.3. Give an example of a mutagen. Give an example of a mutagen.

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chapter 11.1

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