DNADNA Chapter 25 Discovery of DNA Function A. Discovery of DNA 1. first isolated from cells in 1868 2. unknown function B. Griffith Experiments (1928)

Slides:

Advertisements

Similar presentations

Advertisements

Chapter 13 DNA Structure and Function

The Genetic Code Chapter 8 in your textbook

DNA and Heredity. DNA and Heredity DNA is found in the cell’s __nucleus_______. DNA is found in the cell’s __nucleus_______. In the nucleus, we find the.

12. 1 DNA: The Genetic Material. 1)Griffith injects mice with disease causing bacteria  the mice die 2)Griffith injects mice with harmless bacteria 

End Show Slide 1 of 37 Copyright Pearson Prentice Hall 12–1 DNA.

DNA: The Stuff of Life. Griffith and Transformation In 1928, British scientist Fredrick Griffith was trying to learn how certain types of bacteria caused.

Chapter 12 Notes, DNA, RNA, and Protein Synthesis.

The Molecular Basis of Inheritance

DNA Structure and Function Chapter 13. Miescher Discovered DNA 1868 Johann Miescher investigated the chemical composition of the nucleus Isolated an organic.

DNA Structure and Function Chapter 12. Miescher Discovered DNA 1868 Johann Miescher investigated the chemical composition of the nucleus Isolated an organic.

DNA Structure and Function Chapter 12. Discovery of DNA Nucleic Acids were discovered in 1869 by Friedrich Mieschner as a substance contained within nuclei.

DNA: Deoxyribonucleic Acid. I. Molecule for Heredity A. Scientists needed a molecule that could carry 3 main functions: 1. Carry genes from generation.

DNA Structure, Replication, and Organization Chapter 14.

Molecular Biology of the Gene Chapter 10. Viruses are biological saboteurs Hijacking the genetic material of host cells in order to reproduce themselves.

8.1, 8.2, 8.3 Chapter 8 DNA.

DNA and RNA Griffith Griffith was trying to figure out how bacteria made people sick Griffith was trying to figure out how bacteria made people.

12–1 DNA Photo credit: Jacob Halaska/Index Stock Imagery, Inc.

DNA: The Stuff of Life. Griffith and Transformation In 1928, British scientist Fredrick Griffith was trying to learn how certain types of bacteria caused.

It’s the DNA! The information is in the DNA!. DNA History Griffith (1928)– Experimented on mice and observed some harmless strains of bacteria could change.

Chapter 16 RQ 1.What is a virus that infects bacteria called? 2.Who actually took the X-ray diffraction photo of DNA’s structure? 3.What are the bonds.

PROTEIN SYNTHESIS. DNA RNA Protein Scientists call this the: Central Dogma of Biology!

DNA Structure & Replication. Ch Griffith’s Transformation Experiment 1928 – Frederick Griffith is studying how certain strains of bacteria cause.

Chapter 12.1 DNA. Genetics Recap Mendel, through his experiments, concluded that a organism’s traits are a result of the inheritance of genes from that.

Molecular Biology of the Gene Chapter 12

NUCLEIC ACIDS Chapter 12 DNA and RNA. Where did we find Genes and who discovered them?  In 1928 Frederick Griffith tried to figure out how bacteria made.

DNA. How was DNA discovered? There were 3 major experiments that led to the discovery of DNA as the genetic material. –Griffiths Transformations –Avery.

DNA Structure and Function Chapter 13. Early and Puzzling Clues  1800s: Miescher found DNA (deoxyribonucleic acid) by examining pus cells  Early 1900s:

Chapter 12 Notes, DNA, RNA, and Protein Synthesis

DNA –The Language Of Life

D.N.A. DeoxyriboNucleic Acid

DNA: The Genetic Material. Identifying the Genetic Material Experiments of Griffith and Avery yielded results that suggested DNA was genetic material.

Chapter 16: DNA Structure and Function n The history of early research leading to discovery of DNA as the genetic material, the structure of DNA, and its.

DNA Structure & Function Chapter 13. DNA Structure & Function 2 Mr. Karns Genetic Material  Transformation DNA Structure  Watson and Crick DNA Replication.

Lesson Overview 12.1 Identifying the Substance of Genes.

Question of the DAY Jan 5 In prokaryotes, DNA molecules are _______ in shape and located in the _________. In prokaryotes, DNA molecules are _______ in.

DNA. What is the major component of all cells? Why would protein synthesis be important? cellular structures enzymes cell membrane structures organelles.

Chapter 12 DNA Structure and Replication. Transformation Changes one form of bacteria into a different or some cases toxic form of bacteria EX: Griffith’s.

12-1: DNA Biology 2. In the mid 1900’s biologists wondered: How do genes work? What are they made of? How do they determine characteristics? Are they.

Question 1 Are viruses alive?. Study of viral DNA helped unravel the key to the inheritable chemical. Protein – vs- nucleic acid Virus has both and.

DISCOVERY OF DNA Chapter Discovery of Genetic Material Scientists knew genetic information was carried on the chromosomes They did not know where.

Review What organelle is the “control center” of the cell? The nucleus What structures are found in the nucleus? Chromosomes What structures are located.

DNA Structure and Function. Miescher Discovered DNA 1868 Johann Miescher investigated the chemical composition of the nucleus Isolated an organic acid.

DNA The Discovery of DNA. Griffith and Transformation: Transformation: One strain of bacteria (harmless) had changed into disease-causing strain Meant.

DNA Notes. GENOME The nucleus of a human cell contains to genes in the form of DNA called the GENOME.

Aim: How does DNA store the genetic information? DNA.

DNA: The Genetic Material. DNA Deoxyribonucleic Acid.

 Basic building block of nucleic acids  Three parts: › 5-Carbon Sugar › Phosphate group › Nitrogen base.

The History of DNA. 1.Griffith- experiment showed that live uncoated bacteria acquired the ability to make coats from dead coated bacteria. He called.

DNA – Deoxyribonucleic acid. Importance of DNA DNA is the nucleic acid molecule that governs the processes of heredity of all plants and animal cells.

Chapter 12 Section 1: DNA. Objective Describe the experiments and research that lead to the discovery of DNA as the genetic material and the structure.

Standards 5b. Know how to apply base- pairing rules to explain precise copying of DNA during semi- conservative replication.

DNA: The Genetic Material Chapter 12. Fredrick Griffith Performed the 1st major experiment that led to the discovery of DNA as actual genetic material.

DNA: Deoxyribonucleic Acid The Carrier of Genetic Information ESSENTIAL QUESTIONS: 1. Which experiments led to the discovery of DNA as the genetic material?

Chapter #12 – DNA, RNA, & Protein Synthesis. I. DNA – experiments & discoveries A. Griffith and Transformation Frederick Griffith – British scientist.

CHAPTER 12 DNA Identifying the Substance of Genes Griffith was trying to find a vaccine for Streptococcus pneumoniae. Worked with two types or strains.

DNA The mechanism. DNA and inheritance Could predict patterns (Mendel) Did not know why Knew Chromosomes played some role Knew protein and nucleic acid.

DNA STRUCTURE AND REPLICATION CHAPTER What is DNA? Hereditary material present in all living cells Composed of monomers called nucleotides.

DNA Structure and Function

DNA: The Genetic Material

Chapter 12.1 DNA.

Chapter 13 DNA Structure and Function

How is DNA duplicated in the Synthesis Stage?

Warm Up 2 1/27 1. From this experiment, Griffith concluded that one strain of bacteria is changed in form by the gene of another. This is called ______________.

History, Structure, Replication

UNIT: DNA and RNA How is the genetic code contained in DNA and how do cells pass on this information through replication? I. History of DNA A Griffith.

DNA Part 1: DNA Structure and Replication

Biology, 9th ed,Sylvia Mader

DNA Replication Chapter 12 Section 2

DNA, PROTEIN SYNTHESIS, & Mutations

Presentation transcript:

DNADNA Chapter 25

Discovery of DNA Function A. Discovery of DNA 1. first isolated from cells in unknown function B. Griffith Experiments (1928) 1. worked with a pneumonia-causing bacteria 2. two strains R strain: non-fatalS strain: fatal

3. experiment: mice injected with a. R (rough) cells - lived b. S (smooth) cells - died c. heat killed S cells - lived d. heat killed S cells + live R cells - mice died !! 4. analysis of last group showed live S cells and no R cells

1.Transformation of R cells into S cells meant that some Genetic Material must have gone from into the R-cells from the S. 2.Source of Genes: protein or nucleic acids

Hershey-Chase Experiment 1. Was DNA or proteins the genetic material? 2. Bacteriophages - viruses used a. protein coat b. nucleic acid interior (DNA core)

3. Radioactive labeling of protein & DNA

4. Results showed that DNA directed the formation of new viruses, not the protein coat

Discovery of DNA Structure Components of DNA 1. DNA consists of a sugar, base and phosphate group 2. one of 4 possible bases: adenine (A) guanine (G) cytosine (C) thymine (T) Purines Pyrimidines

DNA Structure – The Twisted Ladder

The Nucleotide: 1.Sugar 2.Phosphate Group 3.Nitrogenous Base Ribose Sugar Phosphate Base

Experiments the amount of A = amount of T 2. the amount of C = amount of G 3. ratios vary by species

X-Ray experiments 1.Used X-rays to examine structure of DNA 2.Observed that a. DNA is helical b. DNA exists in long strands c. DNA is highly repetitive

Watson-Crick analysis 1. Constructed a model of DNA structure 2. Phosphate groups from backbone 3. Double-stranded molecule 4. Base=pairing of A-T and G-C 5. Helical shape

DNA Replication & Repair A. Replication 1. replication is semi-conservative 2. major molecules a. helicase - unwinds DNA strands b. DNA polymerase - copies DNA c. DNA ligases - seal newly formed DNA strands

B. DNA Repair 1. DNA polymerase “proofreads” the new strands 2. DNA ligases help to repair mismatched bases

DNA Organization A. Chromosome structure 1. DNA is organized into long molecules called chromosomes 2. chromosome are stabilized by proteins called histones 3. histones organize the DNA