Transcript DNA
Eagle Zone-write the question 1. The cytoplasm is divided in which phase of the cell cycle? 2. Provide the phases of mitosis? 3. What is the purpose of the cell cycle? How does our body replace old cells? 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 • Snakes shed their entire epidermis 4-8 • times per year. Humans shed their entire epidermis every 15 to 30 days. – What factors cause your epidermis (skin) to shed that often? • How do Bloodhounds detect a person’s scent when tracking? Explore 1: Cell Cycle Research • Never Ending Cycle online activity • 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 G1 phase Interphase M phase (Mitosis) is divided into is divided into S phase G2 phase Prophase Metaphase Anaphase Telophase Eagle Zone Review for quiz using the online game or your notes from last class Quiz- write in complete sentences 1. What are the two main phases of the cell cycle? 2. Explain what happens during the Synthesis phase of the cell cycle. 3. How many new cells are produced at the conclusion of the cell cycle? 4. What is the main difference between Mitosis and cytokinesis (what is dividing)? 5. Why is the cell cycle important? (what is its purpose?) The Cell Cycle? Cell cycle – the 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 (growth-Everyday Cellular Activity) S (DNA Synthesis) G2 (growth-Other Organelles Replicated) 2. M-Phase or Mitotic Phase (Shortest phase) Mitosis (Division of nucleus) Cytokinesis (Cytoplasm Division) Explore 2: S Phase Berry Full of DNA Lab Exploration 2 Strawberry DNA Lab 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… Exploration 3 DNA Jewelry Instructions For A Human Being Section 12-1 Explain: DNA Nucleotides Adenine Guanine Phosphate group Cytosine Thymine 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 Phosphate G-C Getting The Letters Out What is a DNA Nucleotide? The basic building block of nucleic acids containing a sugar, base, and a phosphate. P B S S = Deoxyribose Sugar B = Adenine, Guanine, Cytosine, Thymine P = Phosphate Sugar Phosphate Bases (Nitrogenous Bases) These chemicals are often called nitrogenous bases because of the high content of nitrogen (N) atoms 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 Has a Sugar/Phosphate Backbone Bases make up the steps of the ladder A-T G-C DNA Structure QuickTime™ and a Cinepak decompressor are needed to see this picture. Replication Practice On your paper, complete the missing DNA strand by adding the complementary bases. ATCGTTGCCATC TAGCAACGGTAG DNA Replication DNA Replication A Closer Look » » » » DNA before replication: 1 double helix » DNA after replication: 2 identical double helixes » Section 12-2 DNA Replication New strand Original strand DNA polymerase Growth DNA polymerase Growth Replication fork Replication fork New strand Original strand Nitrogenous bases 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 DNA Replication Video • http://highered.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it=swf:: 535::535::/sites/dl/free/0072437316/120076 /micro04.swf::DNA%20Replication%20For k Interphase (G2) • G2 phase: The rest of the cell’s organelles are reproduced. Elaborate: Photo 51 Scientific contributions to the discovery of the DNA structure.