DNA, RNA, and Protein Synthesis Chapter 10 Section 1 Discovery of DNA Meischer Levene Griffith Avery...

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Meischer

Levene

Griffith

Avery

Hershey and Chase

Section 2 DNA Structure

Section 3 DNA Replication

Section 4 Protein Synthesis

Section 1 Discovery of DNAChapter 10

Objectives

• Relate how Griffith’s bacterial experiments showed that a hereditary factor was involved in transformation.

• Summarize how Avery’s experiments led his group to conclude that DNA is responsible for transformation in bacteria.

• Describe how Hershey and Chase’s experiment led to the conclusion that DNA, not protein, is the hereditary molecule in viruses.

Section 1 Discovery of DNAChapter 10

WHAT is the Genetic Material?

• History and Scientist – (http://dnaftb.org/15/concept/)– 1869 Miescher– Early 1900s, Levene– 1928, Griffith– 1940’s Avery– 1952 Hershey and Chase

Section 1 Discovery of DNAChapter 10

Griffith’s Experiments

• Griffith’s experiments showed that hereditary material can pass from one bacterial cell to another.

• The transfer of genetic material from one organism to another organism is called transformation (60427).

• http://dnaftb.org/17/concept/index.html

Chapter 10

Griffith’s Discovery of Transformation

Section 1 Discovery of DNA

Section 1 Discovery of DNAChapter 10

Avery’s Experiments

• Also worked with bacteria cells (Streptococcus pneumonia) and mice

• Avery’s work showed that DNA, is the hereditary material that transfers information between bacterial cells.

Section 1 Discovery of DNAChapter 10

Hershey-Chase Experiment (61132)• Hershey and Chase confirmed that DNA, and not protein,

is the hereditary material.

– Used bacteriaphase, which is a virus that infects bacteria

– Viruses have DNA inside and protein coat outside. • DNA has phosphorus (only phosphorus goes into

bacteria during infection)• Proteins have sulfur

• http://dnaftb.org/18/concept/index.html

Chapter 10The Hershey-Chase Experiment

Section 1 Discovery of DNA

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Meischer

Levene

Griffith

Avery

Hershey and Chase

Section 2 DNA Structure

Section 3 DNA Replication

Section 4 Protein Synthesis

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Section 2 DNA Structure

Nucleotide (sugar, phosphate and nitrogen base)

Bonding within DNA molecules

Complementary Base Pair Rule

Watson and Crick (Franklin and Wilkins)

Why Twist?

Section 3 DNA Replication

Section 4 Protein Synthesis

Section 2 DNA StructureChapter 10

Objectives

• Evaluate the contributions of Franklin and Wilkins in helping Watson and Crick discover DNA’s double helix structure.

• Describe the three parts of a nucleotide.

• Summarize the role of covalent and hydrogen bonds in the structure of DNA.

• Relate the role of the base-pairing rules to the structure of DNA.

Chapter 10Nucleic Acids

• A nucleic acid is a large and complex organic molecule that stores and transports genetic information

• Made of: ______, _____, ______, and _______.• Monomer is called _____________________

• Five carbon sugar named ____________________• Phosphate Group• Nitrogen base

• Guanine• Adenine• Thymine• Cytosine

Section 2 DNA Structure

Chapter 10

Structure of DNA : Nucleotides

Section 2 DNA Structure

Section 2 DNA StructureChapter 10

DNA STRUCTURE

• Bonds Hold DNA Together– Nucleotides along each DNA strand are linked

by covalent bonds between the sugars and phosphates. – Antiparallel: two strands run on opposite

directions. – Complementary nitrogenous bases are

bonded by hydrogen bonds and connect the two strands together.

Section 2 DNA StructureChapter 10

DNA STRUCTURE

• Hydrogen bonding between the complementary base pairs, • Guanine pairs with

Cytosine (3 H-bonds)• Adenine pairs with

Thymine (2 H-bonds)

• 60171

Section 2 DNA StructureChapter 10

DNA STRUCTURE

1953: Watson and Crick created a model of DNA by using Franklin’s and Wilkins’s DNA diffraction

X-rays.

DNA is made of two nucleotide strands that wrap around each other in the shape of a double helix.

Chapter 10

Structure of DNA

Section 2 DNA Structure

Chapter 10

Structure of DNA

Section 2 DNA Structure

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Section 2 DNA Structure

Nucleotide (sugar, phosphate and nitrogen base)

Bonding within DNA molecules

Complementary Base Pair Rule

Watson and Crick (Franklin and Wilkins)

Why Twist?

Section 3 DNA Replication

Section 4 Protein Synthesis

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Section 2 DNA Structure

Section 3 DNA Replication

STEPS and Enzymes used

Semi-conservative Replication

Correct Errors

Section 4 Protein Synthesis

Section 3 DNA ReplicationChapter 10

Objectives

• Summarize the process of DNA replication.

• Identify the role of enzymes in the replication of DNA.

• Describe how complementary base pairing guides DNA replication.

• Compare the number of replication forks in prokaryotic and eukaryotic cells during DNA replication.

• Describe how errors are corrected during DNA replication.

Section 3 DNA ReplicationChapter 10

How DNA Replication Occurs

• DNA replication is the process by which DNA is copied in a cell before a cell divides.

Occurs during the S phase of the cell cycle

Section 3 DNA ReplicationChapter 10

How DNA Replication Occurs, continued

• Steps of DNA Replication – 1. Replication begins with the separation of the

DNA strands by helicases. – 2. Then, DNA polymerases form new strands by

adding complementary nucleotides to each of the original strands.

– Lagging strand and Okazaki Fragments– 3. Each new DNA molecule is made of one strand

of nucleotides from the original DNA molecule and one new strand. This is called semi-conservative replication.

Chapter 10DNA Replication (60172)

Section 3 DNA Replication: Video

Chapter 10

Replication Forks Increase the Speed of Replication

Section 3 DNA Replication

Section 3 DNA ReplicationChapter 10

DNA Errors in Replication :

• Changes in DNA are called mutations. • Due to mutagens or carcinogens

• These can be environmental factors• Smoking , radiation, UV Light.• Video

• DNA proofreading and repair prevent many replication errors.

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Section 2 DNA Structure

Section 3 DNA Replication

STEPS and Enzymes used

Semi-conservative Replication

Correct Errors

Section 4 Protein Synthesis

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Section 2 DNA Structure

Section 3 DNA Replication

Section 4 Protein Synthesis

Central Dogma of Molecular Genetics

Compare RNA and DNA molecules

Steps of Protein Synthesis

Transcription, Genetic Code, and Translation

Human Genome

Section 4 Protein SynthesisChapter 10

Objectives

• Outline the flow of genetic information in cells from DNA to protein.

• Compare the structure of RNA with that of DNA.

• Describe the importance of the genetic code.

• Compare the role of mRNA, rRNA,and tRNA in translation.

• Identify the importance of learning about the human genome.

Section 4 Protein SynthesisChapter 10

Flow of Genetic Information

• The flow of genetic information can be symbolized as

DNA RNA protein.

Section 4 Protein SynthesisChapter 10

RNA Structure and Function

• RNA also made of _________________• Sugar is _____________• Phosphate• Nitrogen bases are

• ____________• ____________• ____________• ____________

• RNA is single stranded and is shorter than DNA.

Compare

DNA and

RNA

60175

Section 4 Protein SynthesisChapter 10

RNA Structure and Function

• Types of RNA– Cells have three major

types of RNA: • messenger RNA

(mRNA)• ribosomal RNA

(rRNA)• transfer RNA

(tRNA)

Section 4 Protein SynthesisChapter 10

RNA Structure and Function (60176)

• mRNA (messenger) carries the genetic “message” from the nucleus to the cytoplasm. (copy of blueprint)

• rRNA (ribosomal) is the major component of ribosomes. (factory)

• tRNA (transfer) takes specific amino acids to the ribosome to make proteins. (shuttle train or taxi for supplies)

Section 4 Protein SynthesisChapter 10

Steps to Protein Synthesis (made of amino acids)Transcription

• During transcription, DNA acts as a template for directing the synthesis of RNA. Video

• DNA is A T G C G C A T T A G C• mRNA is ____________________________

Chapter 10

Transcription:Video

Section 4 Protein Synthesis

Section 4 Protein SynthesisChapter 10

Steps to Protein SynthesisGenetic Code• The nearly universal genetic code identifies the

specific amino acids coded for by each three-nucleotide mRNA codon.

• AUG is a codon for Methionine amino acid. • CCC is a codon for Proline amino acid.

Section 4 Protein SynthesisChapter 10

Section 4 Protein SynthesisChapter 10

Steps to Protein Synthesis Translation

• Steps– During translation, amino acids are picked up and

organized according to mRNA. – tRNA is picking up amino acids from the cytoplasm– mRNA codons move through the ribosome– tRNAs add specific amino acids to create a growing

polypeptide chain (future protein. – The process continues until a stop codon is reached

and the newly made protein is released.

Chapter 10

Translation: Assembling Proteins Video

Section 4 Protein Synthesis

video

Section 4 Protein SynthesisChapter 10

The Human Genome

• The entire gene sequence of the human genome, the complete genetic content, is now known.

• To learn where and when human cells use each of the proteins coded for in the approximately 30,000 genes in the human genome will take much more analysis.

DNA, RNA, and Protein SynthesisChapter 10

Section 1 Discovery of DNA

Section 2 DNA Structure

Section 3 DNA Replication

Section 4 Protein Synthesis

Central Dogma of Molecular Genetics

Compare RNA and DNA molecules

Steps of Protein Synthesis

Transcription, Genetic Code, and Translation

Human Genome

Section 2 Cell Division and CancerChapter 11

Objectives

• Summarize the effects of mutations in causing cancer.

• Compare the characteristics of cancer cells with those of normal cells.

Section 2 Gene Expression in Development and Cell DivisionChapter 11

Gene Expression, Cell Division, and Cancer

• Mutations of proto-oncogenes, which regulate cell growth, or tumor-suppressor genes, which prevent cell division from occurring too often, may lead to cancer.

• Cancer is the uncontrolled growth of abnormal cells.

Chapter 11

Effect of Mutation on Gene Expression

Section 2 Gene Expression in Development and Cell Division

Chapter 11

Section 2 Gene Expression in Development and Cell DivisionChapter 11

Gene Expression, Cell Division, and Cancer, continued

• Gene Expression in Cancer– Unlike normal cells,

cancer cells continue to divide indefinitely, even if they become densely packed.

– Cancer cells will also continue dividing even if they are no longer attached to other cells.

Section 2 Gene Expression in Development and Cell DivisionChapter 11

Gene Expression, Cell Division, and Cancer, continued

• Causes of Cancer– A carcinogen is any substance that can induce or

promote cancer. – Most carcinogens are mutagens, substances that

cause mutations.