1 Genes Are DNA. Ex Biochem c1-genes DNA 2 1.1 Introduction Figure 1.2.

Slides:



Advertisements
Similar presentations
DNA STRUCTURE. NUCLEIC ACIDS Include DNA: Deoxyribonucleic acid RNA: Ribonucleic acid.
Advertisements

At the end of this lecture you should be able to: Recognize the structural components of a DNA and a RNA molecule. (LO 5.1) Recognize and apply the.
Section C Properties of Nucleic Acids
25.1 DNA, Chromosomes, and Genes When a cell is not dividing, its nucleus is occupied by chromatin, DNA (deoxyribonucleic acid), twisted around organizing.
CHAPTER 2 THE STRUCTURE AND FUNCTION OF MACROMOLECULES Section E: Nucleic Acids - Informational Polymers 1.Nucleic acids store and transmit hereditary.
Nucleic Acids and Protein Synthesis
Гените са ДНК Част Introduction Figure 1.2.
Chapter 22 Nucleic Acids and Protein Synthesis
Molecular genetics Previous discussions focused on the individual. Focus has now shifted to genes How are they encoded (3/29, 4/2) How are they replicated.
Properties of Nucleic Acids Lecture 1 of Introduction to Molecular Biology 生理所 蔡少正.
Nucleic acids: Information Molecules
6 The Chemical Structure, Replication, and Manipulation of DNA.
DNA. DNA is… DNA is… –Your genetic code –What tells your cells which proteins to make and when to make them –The code that makes up your genes –Located.
DNA REVIEW GAME.
DNA Biology Lab 11. Nucleic Acids  DNA and RNA both built of nucleotides containing Sugar (deoxyribose or ribose) Nitrogenous base (ATCG or AUCG) Phosphate.
Major Events in Genetics Friedrich Meischer extracted a phosphorous rich material from nuclei of human white blood cells. He named this material.
Chapter 17 Nucleotides and Nucleic acids Chemistry 20.
DNA. Nucleic Acids Informational polymers Made of C,H,O,N and P No general formula Examples: DNA and RNA.
Beyond Mendel - the molecular basis of inheritance, and DNA biology 1.
Chapter 1 Genes Are DNA. 1.1 Introduction chromosome – A discrete unit of the genome carrying many genes. –Each chromosome consists of a very long molecule.
Recall the structure of DNA Describe the differences of DNA Explain how DNA is utilised for different purposes.
Paul D. Adams University of Arkansas Mary K. Campbell Shawn O. Farrell Chapter Nine Nucleic Acids: How Structure.
Protein Synthesis Study Guide
From DNA to Protein. Knowledge of Nucleic Acid Chemistry Is Essential to the Understanding of DNA Structure.
Unit 6: DNA & Protein Synthesis Ch. 28: DNA—Life’s Code DNA = Deoxyribonucleic Acid.
Nucleic Acids Jon Wilson Cell Physiology. Structure of DNA DNA is a double helix made of complimentary antiparallel strands The backbone is constructed.
Visual Anatomy & Physiology First Edition Martini & Ober
Polynucleotides: DNA and RNA
Macromolecules Part IV: Nucleic Acids Informational molecules.
1 DNA Structure The building blocks of nucleic acids are nucleotides, each composed of: –a 5-carbon sugar called deoxyribose –a phosphate group (PO 4 )
Protein Synthesis Review By PresenterMedia.com PresenterMedia.com.
Chapter 5 Part 5 Nucleic Acids 1. The amino acid sequence of a polypeptide is programmed by a discrete unit of inheritance known as a. A gene is a segment.
Unit 6: DNA & Protein Synthesis Ch. 9: Chemistry of the Gene Ch. 10: From Genes to Proteins DNA = Deoxyribonucleic Acid 300.
NUCLEIC ACIDS Genetic material of all known organisms DNA: deoxyribonucleic acid RNA: ribonucleic acid (e.g., some viruses) Consist of chemically.
HUMAN BIOCHEMISTRY  NUCLEIC ACIDS  THE GENETIC CODE.
VIDEO: NUCLEIC ACIDS NUCLEIC ACIDS. Overview: Nucleic Acids – include NUCLEOTIDES and POLYNUCLEOTIDES Many nucleic acids join together to form the macromolecules.
Chapter 10 Part - 1 Molecular Biology of the Gene - DNA Structure and Replication.
Nucleic Acids: How Structure Conveys Information Feb 23, 2016 CHEM 281.
Unit 6: DNA & Protein Synthesis Ch 28: DNA—Life’s Code DNA = Deoxyribonucleic Acid.
Nucleic Acids & DNA replication Revision. Nucleic acids Polymers of monomers called nucleotides. pentose sugar phosphate nitrogenous base.
8.1Nucleotides Starter What is DNA ? Where will you find DNA in a cell? Draw the basic structure of a pentose sugar.
Genes Are DNA Chapter 2. Genes Are DNA Aala A. Abulfaraj.
DNA and RNA Structure Biochemistry Connection: How is structure related to function?
Molecular Biology. The study of DNA and how it serves as a chemical basis of heredity.
DNA Isolation. Nucleic Acid Structure & Function DNA & RNA are composed of Nucleotides A nucleotide consists of three covalently-linked parts: –A nitrogen.
Structure of Nucleic Acids
DNA and Protein Synthesis
Nucleic Acids & Protein Synthesis Chapter 17
Chapter 10 – DNA, RNA, and Protein Synthesis
THE MOLECULE BASIS OF INHERITANCE
Chapter 1 Genes Are DNA.
CHAPTER 5 THE STRUCTURE AND FUNCTION OF MACROMOLECULES
Chapter 5. Replication & Recombination
10.2 DNA and RNA are polymers of nucleotides
The Structure and Function of Large Biological Molecules
Nucleic Acids Section 3.5.
Lec2 م. م مياسه مثنى.
Mrs Manisha Sane PGT Chemistry KV VSN NAGPUR
Fundamentals of Organic Chemistry
Chapter Outline 14.1 Nucleic Acid Building Blocks
Welcome to the world of DNA
Cellular Metabolism Chapter 4
DNA is the Hereditary Material
Chapter 1 Genes Are DNA.
DNA STRUCTURE AND FUNCTION
5. Nucleic acids Lecture 1.
DNA and RNA structure The painting “Dawn of the Double Helix” composes the DNA duplex as human figures. The theme in this painting is “Life forms: The.
From Gene to Protein Part 1: Replication.
Structure and function of DNA
Fundamentals of Organic Chemistry
Presentation transcript:

1 Genes Are DNA

Ex Biochem c1-genes DNA Introduction Figure 1.2

Ex Biochem c1-genes DNA Polynucleotide Chains Nitrogenous Bases 鹼基 Linked to a Sugar – Phosphate Backbone A nucleoside consists of a purine or pyrimidine base linked to position 1 of a pentose sugar.

Ex Biochem c1-genes DNA 4 Transfection DNA can enter eukaryotic cells and produce functional proteins Become part of the genome DNA can also be introduced into eggs by microinjection Become part of the genome

Ex Biochem c1-genes DNA 5 Nucleic acid structure Positions on the ribose ring are described with a prime (′) to distinguish them. The difference between DNA and RNA is in the group at the 2′ position of the sugar. DNA has a deoxyribose sugar (2′ – H) RNA has a ribose sugar (2′ – OH) A nucleotide consists of a nucleoside linked to a phosphate group on either the 5′ or 3′ position of the (deoxy)ribose. Successive (deoxy)ribose residues of a polynucleotide chain are joined by a phosphate group Between the 3′ position of one sugar and the 5′ position of the next sugar One end of the chain (left) has a free 5′ end The other end has a free 3′ end

Ex Biochem c1-genes DNA 6 Nucleosides Nucleoside: Nucleoside: a compound that consists of D- ribose 核糖 or 2-deoxy-D-ribose 去氧核糖 bonded to a nucleobase by a  -N-glycosidic bond

Ex Biochem c1-genes DNA 7 Nucleotide Nucleotide: Nucleotide: a nucleoside in which a molecule of phosphoric acid is esterified with an -OH of the monosaccharide, most commonly either the 3 ’ -OH or the 5 ’ -OH

Ex Biochem c1-genes DNA 8 Nucleotides Deoxythymidine 3 ’ -monophosphate (3 ’ - dTMP)

Ex Biochem c1-genes DNA 9 DNA Structure

Ex Biochem c1-genes DNA 10 Pyrimidine/Purine Bases

Ex Biochem c1-genes DNA 11 Other Bases Several “ unusual ” bases occur, principally but not exclusively, in transfer RNAs

Ex Biochem c1-genes DNA 12 Figure 1.07: A polynucleotide has a repeating structure.

Ex Biochem c1-genes DNA 13 DNA Structure Writing a DNA strand an abbreviated notation even more abbreviated notations: pdApdCpdGpdT, or pdACGT, or ACGT

Ex Biochem c1-genes DNA DNA Is a Double Helix The B-form of DNA is a double helix consisting of two polynucleotide chains that run antiparallel. The nitrogenous bases of each chain are flat purine or pyrimidine rings They face inward They pair with one another by hydrogen bonding to form A-T or G-C pairs only

Ex Biochem c1-genes DNA 15 Figure 1.08: The double helix has constant width.

Ex Biochem c1-genes DNA 16 Figure 1.09: Flat base pairs connect the DNA strands.

Ex Biochem c1-genes DNA 17 The diameter of the double helix is 20 Å There is a complete turn every 34 Å Ten base pairs per turn The double helix forms: a major (wide) groove a minor (narrow) groove Figure 1.10

Ex Biochem c1-genes DNA 18 DNA double helix

Ex Biochem c1-genes DNA DNA Replication Is Semiconservative The Meselson – Stahl experiment used density labeling to prove that: The single polynucleotide strand is the unit of DNA that is conserved during replication Each strand of a DNA duplex acts as a template 模版 to synthesize a daughter strand.

Ex Biochem c1-genes DNA 20 Figure 1.11: Base pairing accounts for specificity of replication. DNA replication is semiconservative

Ex Biochem c1-genes DNA 21 Semiconservative Replication

Ex Biochem c1-genes DNA 22 Enzymes The enzymes that synthesize DNA are called DNA polymerases (DNA 聚合脢 ) The enzymes that synthesize RNA are called RNA polymerases Nucleases are enzymes that degrade nucleic acids They include DNAases and RNAases They can be divided into endonucleases and exonucleases.

Ex Biochem c1-genes DNA 23 Figure 1.14: Endonucleases attack internal bonds. Figure 1.15: Exonucleases nibble from the ends.

Ex Biochem c1-genes DNA Genetic Information Can Be Provided by DNA or RNA Cellular genes are DNA Viruses and viroids may have genomes of RNA DNA is converted into RNA by transcription RNA may be converted into DNA by reverse transcription The translation of RNA into protein is unidirectional. Figure 1.16

Ex Biochem c1-genes DNA 25 Figure 1.18: Genomes vary greatly in size.

Ex Biochem c1-genes DNA Nucleic Acids Hybridize by Base Pairing Heating causes the two strands of a DNA duplex to separate. The T m is the midpoint of the temperature range for denaturation. Complementary single strands can renature when the temperature is reduced. Denaturation and renaturation/hybridization 雜交 can occur with the combinations: DNA – DNA DNA – RNA RNA – RNA They can be intermolecular or intramolecular

Ex Biochem c1-genes DNA 27 Figure 1.20: DNA can be denatured and renatured.

Ex Biochem c1-genes DNA Mutations Change the Sequence of DNA All mutations 突變 consist of changes in the sequence of DNA. Mutations may: occur spontaneously be induced by mutagens Figure 1.22

Ex Biochem c1-genes DNA Mutations May Affect Single Base Pairs or Longer Sequences A point mutation changes a single base pair. Point mutations can be caused by: the chemical conversion of one base into another mistakes that occur during replication Insertions are the most common type of mutation They result from the movement of transposable elements

Ex Biochem c1-genes DNA 30 A transition replaces a G-C base pair with an A-T base pair or vice versa. Figure 1.23Figure 1.24

Ex Biochem c1-genes DNA The Effects of Mutations Can Be Reversed Forward mutations inactivate a gene Back mutations (or revertants) reverse their effects Insertions can revert by deletion of the inserted material Deletions cannot revert Suppression occurs when a mutation in a second gene bypasses the effect of mutation in the first gene. Figure 1.25