RNA STRUCTURE 1. Types of nucleic acid DNA – Deoxyribonucleic acid RNA – ribonucleic acid 2.

Slides:



Advertisements
Similar presentations
Genome Organisation I Bacterial chromosome is a large (4 Mb in E coli) circular molecule Bacterial cells may also contain small circular chromosomes called.
Advertisements

PowerPoint Presentation Materials to accompany
DNA STRUCTURE. NUCLEIC ACIDS Include DNA: Deoxyribonucleic acid RNA: Ribonucleic acid.
Introduction to molecular biology. Subjects overview Investigate how cells organize their DNA within the cell nucleus, and replicate it during cell division.
MBB 407/511 Lecture 21: Eukaryotic DNA Replication Nov. 29, 2005.
Chromosomes and DNA Replication
Nucleic Acids nucleic acids store and transmit hereditary information
BackBack Next Next CLOSE WINDOW.
Chapter 6 DNA  Consists of Deoxyribose sugar Phosphate group A, T, C, G  Double stranded molecule (Double Helix) Two strands of DNA run antiparallel.
Central dogma: Information flow in cells. Nucleotides Pyrimidine bases: Cytosine (C), Thymine (T), Uracil (U, in RNA) Purine bases: Adenine (A), Guanine.
DNA Structure/Composition Taryono Faculty of Agriculture Gadjah Mada University.
Central dogma: Information flow in cells. Nucleotides Pyrimidine bases: Cytosine (C), Thymine (T), Uracil (U, in RNA) Purine bases: Adenine (A), Guanine.
Genes & Chromosomes Chapter 24. Central Dogma (p.906) DNA replicates  more DNA for daughters (Genes of) DNA transcribed  RNA –Gene = segment of DNA.
NUCLEIC ACIDS & PROTEINS
3.1 & & 7.2.  Genetic information is stored in molecules called nucleic acids.  There are 2 types of nucleic acids  DNA: deoxyribonucleic acid.
Chapter 5 (Please do read every single page)
DNA Structure DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix. A molecule of DNA is made up of millions.
Cell and Molecular Biology
Gene and Chromosome. DNA is the genetic material.
Spring 2009: Section 3 – lecture 1 Reading – Chapter 3 Chapter 10, pages
Genome organization. Nucleic acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) store and transfer genetic information in living organisms.
CHAPTER 24 Genes and Chromosomes
DNA STRUCTURE. NUCLEIC ACIDS Nucleic acids are polymers Nucleic acids are polymers Monomer---nucleotides Monomer---nucleotides Nitrogenous bases Nitrogenous.
Chapter 17 Nucleotides and Nucleic acids Chemistry 20.
CHAPTER 24 Genes and Chromosomes
Genetics: Chromosome Organization. Chromosomes: Structures that contain the genetic material (DNA) Genome – complete set of genetic material in a particular.
Hereditary Material - DNA In 1952, Alfred Hershey and Martha Chase studied the genetic material of the virus called T2 that infects the bacterium E.Coli.
DNA (Deoxyribonucleic Acid). A HISTORY OF DNA DNA double helixDiscovery of the DNA double helix A. Frederick Griffith – Discovers that a factor in diseased.
Chromosomes & DNA Replication. I. DNA & Chromosomes A. DNA is found in different ways depending on the type of cell you are looking at – 1. In prokaryotic.
Chapter 24 Genes and Chromosomes
CHAPTER 24 Genes and Chromosomes  Organization of information in chromosomes  DNA supercoiling  Structure of the chromosome Key topics:
Intro to Chromosome structure
(CHAPTER 10- Brooker Text) Chromosomal Organization & Molecular Structure Sept 13, 2007 BIO 184 Dr. Tom Peavy.
Genes & Chromosomes Part III, Chapters 24, 25. Central Dogma DNA replicates  more DNA for daughters (Gene w/in) DNA transcribed  RNA –Gene = segment.
Molecular Genetics Introduction to
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 )
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.
DNA Structure and Replication (Ch. 12-1, 12-2). DNA DNA is one of the 4 types of macromolecules known as a nucleic acid. DNA is one of the 4 types of.
Information Pathways Genes and Chromosomes
Molecular Genetics: 1 The Structure and Function of DNA.
DNA- Deoxyribonucleic acid Each nucleotide of DNA is composed of a phosphate group, a sugar called deoxyribose and a molecule that is called a nitrogenous.
CHROMOSOMES & DNA REPLICATION DNA WHERE IS DNA FOUND IN THE CELL? IN PROKARYOTIC CELLS, DNA IS LOCATED IN THE CYTOPLASM. MOST PROKARYOTES HAVE.
Chapter 12 DNA and RNA.
Chapter 12 DNA Information and Heredity, The Cellular Basis of Life.
The Genetic Material Must Exhibit Four Characteristics For a molecule to serve as the genetic material, it must be able to replicate, store information,
CHROMOSOMAL ORGANIZATION Chapter 16, Section 3. Chromatin: DNA at its associated proteins. DNA, the Double Helix ■Sugar-phosphate backbones on the exterior.
 Genetic information is stored in molecules called nucleic acids.  There are 2 types of nucleic acids  DNA: deoxyribonucleic acid ◦ Double stranded.
 Naturally occurs in cells  Scientists use cell cultures as a source of DNA  Different types of cells are grown in mediums  Cell cultures are collected.
DNA S TRUCTURE. G ENERAL O VERVIEW DNA is short for deoxyribonucleic acid. DNA and RNA ( ribonucleic acid ) are called nucleic acids because they are.
L. Bahiya Osrah LAB 1 INTRODUCTION TO NUCLEIC ACIDS STRUCTURAL PROPERTIES.
Aim: How is DNA organized in a eukaryotic cell?. Why is the control of gene expression more complex in eukaryotes than prokaryotes ? Eukaryotes have:
The Molecular Basis of Inheritance
Introduction to Studying DNA
Biochemical Organization &Functions of DNA
Concept 16.3 A Chromosome consists of a DNA molecule packed together with proteins The bacterial chromosome is a double-stranded, circular DNA molecule.
Unit 5: DNA and Protein Synthesis
Transcription & Translation
Chromosome Structure and
Prokaryotic and Eukaryotic Cells: What do all cells have in common?
Chromosome Structure and
Chapter 12 DNA and RNA.
Function and Packaging of DNA
Introduction to Studying DNA
12.2 – Chromosomes and DNA Replication
Chromosome Organization
Important Organic Molecules II
DNA Packaging.
Genes & Chromosomes Compaction of DNA Supercoiling Relaxed.
CHAPTER 19 THE ORGANIZATION AND CONTROL OF EUKARYOTIC GENOMES
Intro to Chromosome structure
Presentation transcript:

RNA STRUCTURE 1

Types of nucleic acid DNA – Deoxyribonucleic acid RNA – ribonucleic acid 2

O O=P-O OPhosphate Group Group N Nitrogenous base (A, G, C, or U) (A, G, C, or U) CH2 O C1C1 C4C4 C3C3 C2C2 5 Sugar Sugar(deoxyribose) Nucleic acids consist of repeating nucleotide that have phosphate ester, a pentose sugar, and a heterocyclic base. 3

4

RNA is single stranded 5

6

7

RNA SYTHESIS 8

HIGHER ORDER DNA STRUCTURE TERTIARY PACKAGING OF DNA INTO CHROMOSOME 9

SIZE OF DNA DNA Molecules are much longer than the cellular packages that contain them Viruses Usually consist of no more than one genome (usually a single RNA or DNA molecule) Almost all have RNA genomes Although viral genomes are small-the contour lengths of their DNA s are much greater than the long dimensions of the viral particles that contain them-efficient DNA packaging! 10

Bacteria E.Coli contain almost 100 times DNA length compare to virus Double stranded circular DNA molecule In addition, many bacteria contain one or more small circular DNA molecules that are free in the cytosol – plasmids (can be few thousand pairs). Eg. Plasmid carry multidrug resistance gene SIZE OF DNA 11

DNA is packed into chromosomes Each chromosome contain a single, very large, duplex DNA molecule Mitochondrial DNA (<20kbp) codes for the mitochondrial tRNA and rrNA and few mitochondrial proteins EUKARYOTES 12

Genomic DNA May be Linear or Circular Most DNA exist as double-helical complexes, except for few bacteriophage that can aquire SS form Depending on the source of DNA, the complexes can be linear or circular Circular DNA - formation of phosphodiester bonds between the 3’-5’ termini of linear polynt by enzyme DNA ligase 13

DNA SUPERCOILING Cellular DNA- extremely compacted – implying high degree of structural organization Important property of DNA structure- supercoling – the coiling of a coil DNA is coiled in the form of double helix – further coiling of double helix produce supercoil No bending of DNA upon itself- relaxed state Tertiary structure of DNA 14

Circular DNA without other manipulations – relaxed state – decrease activity in replication and transcription The biological form- superhelical topology created by either unwinding or overwinding the double helix Underwound DNA/right handed superhelix – negative supercoil Overwound DNA/left handed superhelix-positive supercoil Naturally occuring – negative supercoil Genomic DNA May be Linear or Circular 15

Topoisomerase Enzyme Involve in changing the supercoiled state of DNA 2 Classes – Class I and Class II Class I-cut the phosphodiester backbone of one strand DNA, pass the other end through Class II – Cut both strands of DNA, pass some of the remaining DNA helix between the cut ends, and then reseal –e.g. DNA gyrase These 2 enzymes play important role in replication and transcription 16

17

Packaging of Prokaryotic DNA DNA is organized as a single chromosome that contains ds circular supercoil Average bacterium DN, e.g E.Coli – contour length of DNA is 80X larger than the diameter of the cell 1mm chromosome need to be packed in 1µm cell Bacterial chromosomes are organized into compacted structure-nucleoids- interaction with HU protein – forming DNA-HU complex 18

EUKARYOTES 19

Packaging of eukaryotic DNA Majority of DNA in euk cells is packaged into nucleosome Can reduce the length into 10,000 fold Nucleosome- composed of a core of eight histone proteins and the DNA wrapped around them Five types of histones- H1A, H2A,H2B,H3 and H4 20

DNA ORGANIZATION IN EUKARYOTE 1.DNA in the form of double helix 2.DNA is tightly associated with proteins histones producing nucleosomes- 10nm fibrils 3.Nucleosomes are organized into 30nm fibers and the fibers are extensively folded to provide 10,000 fold compaction required to fit a typical eukaryotic chromosome into cell nucleus 4.The higher order folding involves attachment to a nuclear scaffold that contains histone H1, topoisomerase II and SMC proteins 5.Youtube: How DNA is packaged (Advanced) 21

EUKARYOTES Contain centromere-a sequence of DNA that functions during cell division as an attachment point for proteins that link the chromosome to the mitotic spindle Telomeres – sequence at the end of eukaryotic chromosomes that help stabilize chromosome 22

The Importance of DNA Packaging Chromosome is the compact form of DNA that readily fits the cell Protect DNA from damage-allowing information encoded to be transmitted efficiently to daughter cells 23