The Integumentary System - Download Now PowerPoint

							The Integumentary System
     More Than Skin Deep
          Cell Cycle
                 TAKS

• TAKS Objective 2 – The student will
 demonstrate an understanding of
 living systems and the environment.
                     TEKS
• The student knows the structures and functions
  of nucleic acids in the mechanisms of genetics.
  The student is expected to
(A)describe components of
  deoxyribonucleic acid (DNA); and illustrate
  how information fro specifying traits of an
  organism is carried in the DNA;
(B)explain replication, transcription, and
  translation using models of DNA and ribonucleic
  acid
Engage

         • Humans shed their
             entire epidermis every
             15 to 30 days.
         •   Bloodhounds detect
             this upon tracking
Explore 1: Cell Cycle Research

• Student will complete a cell cycle diagram
 with detailed description of cellular activity
 in each of the cell cycle phases.
Cell Cycle
Explain: Cell Cycle

• All cells constantly replace themselves by
  a process called mitosis, which is a small
  section of the cell cycle.
• New skin cells push the older generation
  of cells toward the surface of the skin,
  where they are finally shed as a flake-like,
  lifeless, residue
  What are the two main phases of the cell cycle?


                                        Cell Cycle

                                          includes




             Interphase                                          M phase
                                                                 (Mitosis)



           is divided into                                    is divided into




G1 phase      S phase        G2 phase         Prophase   Metaphase       Anaphase   Telophase
The Cell Cycle?
       Cell cycle - changes a cell goes
        through during its life span.
        contains 2 main steps.
         1.Interphase (LONGEST phase of the
          cell cycle and has three parts)
                G1 (Everyday Cellular Activity)
                S (DNA Synthesis)
                G2 (Other Organelles Replicated)
         2. M-Phase or Mitotic Phase (Shortest
          phase)
            Mitosis (Nuclear Division)
            Cytokinesis (Cytoplasm Division)
Explore 2: S Phase
Berry Full of DNA Lab
Photo 51
   Scientific contributions to the discovery
    of the DNA structure.
     Review: Interphase (G1)
•   What is the main purpose of a cell that is in G1?
•   G1 Phase: During this stage the cell is carrying on
    its everyday activities.
•   If the cell’s surface to volume ratio gets too big
    then the cell must get ready to divide.
•   Do some cells entering a resting state?
•   What is this phase called?
•   G0 Phase: Resting State - Some cells leave the
    cell cycle and stay here much longer than others
    ex) brain, nerve, etc…
Section 12-1


       Explain: DNA
                              Nucleotides
                   Purines              Pyrimidines
               Adenine    Guanine   Cytosine        Thymine




                  Phosphate
                  group                        Deoxyribose
Section 12-1


   Structure of DNA
                   Nucleotide

                                    Hydrogen
                                    bonds




 Sugar-phosphate
        backbone
                                Key
                                Adenine (A)
                                Thymine (T)
                                Cytosine (C)
                                Guanine (G)
    DNA
   Deoxyribose Sugar
   Base Pairs
          A-T           G-C




   Phosphate
What is a Nucleotide?
The basic building block of nucleic acids
  containing a sugar, base, and a
  phosphate.

                 P
                                 B
                        S


S = Deoxyribose Sugar or Ribose Sugar
B = Adenine, Guanine, Cytosine, Thymine or Uracil
P = Phosphate
Sugar
    Bases
    (Nitrogenous Bases)
   These chemicals are often called nitrogenous bases
    because of the high content of nitrogen (N) atoms
Purines
Pyrimidines


                 1) Cytosine (C)
                 2) Thymine (T)
                 3) Uracil (U)
Phosphate
    Nucleotide




   The Sugar and the Phosphate make up the
    backbone of the structure
   The bases make up the rungs of the ladder
Different Types of Nucleotides in
DNA
Deoxy---Adenine   Deoxy----Thymine
    |                |
    P               P

 Deoxy---Cytosine Deoxy----Guanine
    |               |
    P               P
Many Nucleotides Together
Parts of DNA and RNA
                 Have a
                  Sugar/Phosphate
                  Backbone
                 Bases make up the
                  steps of the ladder
                 A-T---DNA
                 A-U---RNA
                 G-C---DNA & RNA
DNA Structure


             QuickTime™ an d a
           Cinepak decompressor
      are need ed to see this p icture .
Practice
   On your paper, complete the missing
    DNA strand by adding the
    complementary bases.
   ATCGTTGCCATC
   TAGCAACGGTAG
    DNA Replication
     A Closer Look
»       DNA before replication: 1 double helix
»
»
»



»       DNA after replication: 2 identical double
                               helixes
»
Section 12-2


   DNA Replication
                                        Original
                                        strand         DNA
                        New strand                     polymerase




                                      Growth
                DNA
                polymerase
                                     Growth




  Replication                                               Replication   Nitrogenous
  fork                                                      fork          bases



                                         New strand   Original
                                                      strand
Getting Ready
        Step 1
Unwinding and Unzipping
Unwind and Unzip
Helicase Enzyme
     Step 2
    Separates
Polymerase Enzyme
             Step 3
Picking up Complementary Bases
Separation and Adding Bases
          5’----3’
Step 4
Rewind
     Two New DNA Molecules
• Each DNA Molecule with a Parent and Daughter Strand
Interphase (G2)
•   G2 phase: The rest of the cell’s
    organelles are reproduced.
Elaborate: DNA Jewelry