AP Biology A A A A T C G C G T G C T Macromolecules: Nucleic Acids  Examples:  RNA (ribonucleic acid)  single helix  DNA (deoxyribonucleic acid)

Slides:



Advertisements
Similar presentations
DNA Structure & Replication Chapter 15 continued Bedford County Public Schools – Jami N. Key.
Advertisements

AP Biology Nucleic acids AP Biology Nucleic Acids Information storage.
Nucleic acids Nucleic Acids Information storage.
AP Biology Nucleic acids AP Biology Nucleic Acids.
AP Biology Nucleic acids AP Biology Nucleic Acids Information storage.
DNA ( Deoxyribonucleic acid ) Site: Human DNA is present in the nucleus and mitochonria Function: carry genetic information. Structure: Human DNA consists.
AP Biology Nucleic acids AP Biology Nucleic Acids Information storage.
–DNA functions as the inherited directions for a cell or organism. –How are these directions carried out? Flow of Genetic Information Gene DNA RNA Protein.
Nucleic Acids and DNA Replication. 1. What is the role of nucleic acid? 2. What is the monomer of a nucleic acid? 3. The monomer of a nucleic acid is.
Unit 9: The Central Dogma Honors Biology.  The process of DNA replication is fundamentally similar for prokaryotes and eukaryotes.  DNA replication.
AP Biology DNA Replication Ch.12.2 AP Biology DNA Replication  Purpose: cells need to make a copy of DNA before dividing so each daughter.
Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies DNA Replication.
Genetics DNA Replication Genetics Why do cells divide…  for reproduction  One celled organisms (clones)  for growth & development  From.
AP Biology Synthesis of DNA June
DNA. DNA or Protein the Genetic material?? Hershey-Chase Experiment hill.com/sites/ /student_view0/ chapter14/animations.html#
DNA. Nucleic Acids Informational polymers Made of C,H,O,N and P No general formula Examples: DNA and RNA.
REVIEW DNA Structure. Deoxyribonucleic Acid DNA Deoxyribose sugar Double helix A -2-T, C-3-G Strands are complementary Purines: A and G Pyrimidines: T.
AP Biology DNA Replication AP Biology Watson and Crick 1953 article in Nature.
Beyond Mendel - the molecular basis of inheritance, and DNA biology 1.
DNA Structure and Replication. CENTRAL DOGMA Get out your macromolecule booklets, and get ready to tell me about the structure of DNA. –And put on your.
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 Replication IB Biology HL 1 Mrs. Peters Spring 2014.
DNA Replication DNA Replication is a semiconservative process where the new DNA is copied onto a parental (conserved) strand. It takes place with surprising.
3.4 & 7.2 DNA Replication Pp 16 – 19 & Pp 58 – 60 &
AP Biology Nucleic Acids Information storage Energy Transfer.
AP Biology The Building Blocks  3.3 Nucleic Acids.
AP Biology Nucleic acids AP Biology Nucleic Acids Information storage.
Photo 51 Rosalind Franklin Maurice Wilkins James D. Watson Francis Crick
DNA Replication Lecture 11 Fall Read pgs
AP Biology Nucleic Acids Nucleic Acids Function: – store & transmit hereditary information polymers = – RNA (ribonucleic acid) – DNA (deoxyribonucleic.
AP Biology A A A A T C G C G T G C T Macromolecules: Nucleic Acids  Examples:  RNA (ribonucleic acid)  single helix  DNA (deoxyribonucleic acid)
AP Biology S-Phase: Deoxyribonucleic Acid The Molecular Basis of Inheritance DNA Structure DNA Replication.
DNA replication Chapter 16. Summary of history Griffith Mice & Strep Transformation External DNA taken in by cell.
AP Biology A A A A T C G C G T G C T Macromolecules: Nucleic Acids  Examples:  RNA (ribonucleic acid)  single helix  DNA (deoxyribonucleic acid)
DNA, RNA, Proteins. Nucleic Acids: “Information Molecules” DNA – Sugar Deoxyribose – Nitrogenous Bases Adenine Guanine Cytosine Thymine RNA – Sugar Ribose.
AP Biology Nucleic Acids Information storage proteins DNA Nucleic Acids  Function:  genetic material  stores information  genes  blueprint for building.
Unit 2: Molecular Genetics Bi 1d: Central Dogma Bi 5a: DNA, RNA, protein structure and function Bi 5b: Base pairing rules.
INTERACTIVE NOTES PGS CHROMOSOMES & DNA REPLICATION.
1.DNA MOLECULES ARE LONG POLYMERS MADE UP OF REPEATING NUCLEOTIDES.
The Molecular Basis of Inheritance.  Your DNA – contained in 46 chromosomes you inherited from your parents in mitochondria you inherited from your mother.
Chapter 16.2 DNA Replication and Repair. Recap Nitrogen base pairings A – T C – G Adenine and Guanine are purines -2 rings Cytosine and Thymine are pyrimidines.
AP Biology Nucleic acids AP Biology Nucleic Acids Information storage.
AP Biology Nucleic Acids AP Biology Nucleic acids.
AP Biology Nucleic Acids Information storage.
AP Biology Nucleic acids AP Biology Nucleic Acids Information storage.
Molecular Biology. The study of DNA and how it serves as a chemical basis of heredity.
DNA Replication Functions of DNA 1. Replication – Occurs before Mitosis and meiosis only Produces an exact copy of DNA 2. Transcription – DNA makes mRNA.
DNA Replication.
DNA Replication DNA → RNA → Protein replication
Nucleic Acids Information storage
Transcription & Translation
DNA Structure & Replication
Nucleic Acids Information storage
The structure of Nucleic Acids
Copying the genetic blueprint
copyright cmassengale
Unit 6 – Meiosis, Replication, and Protein Synthesis
Chapter 13 DNA Replication.
Deoxyribonucleic Acid
DNA REPLICATION.
DNA and Replication.
Nucleic Acids Information storage
DNA: The Genetic Material
DNA replication Chapter 16.
Nucleic Acids A macromolecule that carries our genetic material (DNA)
DNA, Genes and Genomics.
DNA Structure and Replication
Deoxyribonucleic Acid
Nucleic Acids Information storage
A T C G Isn’t this a great illustration!?.
Presentation transcript:

AP Biology A A A A T C G C G T G C T

Macromolecules: Nucleic Acids  Examples:  RNA (ribonucleic acid)  single helix  DNA (deoxyribonucleic acid)  double helix  Structure:  monomers = nucleotides RNADNA

AP Biology Nucleotides  3 parts  nitrogen base (C-N ring)  pentose sugar (5C)  ribose in RNA  deoxyribose in DNA  phosphate (PO 4 ) group Are nucleic acids charged molecules? Nitrogen base I’m the A,T,C,G or U part!

AP Biology Types of nucleotides  2 types of nucleotides  different nitrogen bases  purines  double ring N base  adenine (A)  guanine (G)  pyrimidines  single ring N base  cytosine (C)  thymine (T)  uracil (U) Purine = AG Pure silver!

AP Biology Nucleic polymer  Backbone  sugar to PO 4 bond  phosphodiester bond  new base added to sugar of previous base  polymer grows in one direction  N bases hang off the sugar-phosphate backbone Dangling bases? Why is this important?

AP Biology Pairing of nucleotides  Nucleotides bond between DNA strands  H bonds  purine :: pyrimidine  A :: T  2 H bonds  G :: C  3 H bonds Matching bases? Why is this important?

AP Biology DNA molecule  Double helix  H bonds between bases join the 2 strands  A :: T  C :: G H bonds? Why is this important?

AP Biology Copying DNA  Replication  2 strands of DNA helix are complementary  have one, can build other  have one, can rebuild the whole

AP Biology When does a cell copy DNA?  When in the life of a cell does DNA have to be copied?  cell reproduction  mitosis  gamete production  meiosis

AP Biology But how is DNA copied?  Replication of DNA  base pairing suggests that it will allow each side to serve as a template for a new strand

AP Biology Models of DNA Replication Semiconservative replication  Meselson & Stahl  label “parent” nucleotides in DNA strands with heavy nitrogen = 15 N  label new nucleotides with lighter isotope = 14 N 1958 parentreplication 15 N parent strands 15 N/ 15 N

AP Biology Semiconservative replication  Make predictions…  15 N strands replicated in 14 N medium  1st round of replication?  2nd round? 1958 where should the bands be?

AP Biology DNA Replication  Origin(s) of replication  specific sequence of nucleotides recognized by replication enzymes  Prokaryotes –  Single sequence  Bidirectional Synthesis  Replication proceeds in both directions  Eukaryotes –  hundreds/thousands of origin sites per chromosome  Replication forks  Bubbles elongate as DNA is replicated and eventually fuse

AP Biology Bidirectional Synthesis  In prokaryotes, the circular DNA is opened up, and synthesis occurs in both directions

AP Biology  In eukaryotes, the linear DNA has many replication forks Replication forks

AP Biology

DNA Replication Issues 1. DNA strands must be unwound during replication  DNA helicase  unwinds the strands  Single stranded binding proteins (SSB)  prevent immediate reformation of the double helix  Topoisomerases  “untying” the knots that form

AP Biology Replication Issues 2. A new DNA strand can only elongate in the 5’  3’ direction  RNA primers initiates DNA polymerase  DNA polymerase can add only at the 3’ end (sliding clamp holds DNA polymerase on DNA strand)  Replication is continuous on one strand  Leading Strand  discontinuous on the other  Lagging strand  Okazaki fragments

AP Biology Okazaki fragments  Synthesis of the leading strand is continuous  The lagging strand (discontinuous) is synthesized in pieces called Okazaki fragments

AP Biology

Replication Issues 3. DNA polymerase cannot initiate synthesis because it can only add nucleotides to end of an existing chain  Requires a “primer” to get the chain started  RNA Primase  can start an RNA chain from a single template strand by synthesizing RNA primers  DNA polymerase can begin its chain after a few RNA nucleotides have been added

AP Biology

Summary  At the replication fork, the leading strand is copied continuously into the fork from a single primer  Lagging strand is copied away from the fork in short okazaki fragments, each requiring a new primer

AP Biology

Learning Check 1. What is the purpose of DNA replication? 2. How is the new strand ensured to be identical to the original strand? 3. How is replication on one side of the strand different from the other side?

AP Biology Replication Issues 4. Presence of RNA primer on the 5’ ends of daughter DNA leading strand leaves a gap of uncopied DNA  Repeated rounds of replication produce shorter and shorter DNA molecules  Telomeres  protect genes from being eroded through multiple rounds of DNA replication

AP Biology Telomeres  Ends of eukaryotic chromosomes, the telomeres, have special nucleotide sequences  Humans - this sequence is typically TTAGGG, repeated ,000 times  Telomerase adds a short molecule of RNA as a template to extend the 3’ end  Room for primase & DNA pol to extend 5’ end

AP Biology Summary  Explain how the cell overcomes each of the following issues in DNA replication 1. DNA strands must be unwound during replication 2. A new DNA strand can only elongate in the 5’  3’ direction 3. DNA polymerase cannot initiate synthesis and can only add nucleotides to end of an existing chain 4. Presence of RNA primer on the 5’ ends of daughter DNA leading strand leaves a gap of uncopied DNA