Unit IV hapter 04 ellular Function opyright McGraw-Hill Education. Permission required for reproduction or display. 1
Fig. 4.2 opyright McGraw-Hill Education. Permission required for reproduction or display. (a) G G T A A T (b) G A T G T A G Sugar phosphate backbone (c) Hydrogen bond Sugar phosphate backbone
Fig. 4.1 opyright McGraw-Hill Education. Permission required for reproduction or display. Adenine NH 2 H N N N N H O HO P O H 2 O OH H H H H OH H (a) Phosphate Deoxyribose Purines NH 2 N H N N Adenine (A) H NH O N H HN NH N NH 2 Guanine (G) Pyrimidines H H NH 2 N H 3 H O NH HN O H N H O N H O O N H H ytosine () Thymine (T) Uracil (U) (b)
Fig. 4.4 opyright McGraw-Hill Education. Permission required for reproduction or display. 2 nm 1 DNA double helix hromatin ore particle Nucleolus Linker DNA Nucleosome 11 nm 2 DNA winds around core particles to form nucleosomes 11 nm in diameter 30 nm 3 Nucleosomes fold accordionlike into zigzag fiber 30 nm in diameter (a) 50 nm In dividing cells only 300 nm 4 30 nm fiber is thrown into irregular loops to form a fiber 300 nm thick hromatids entromere 700 nm 5 In dividing cells, looped chromatin coils further into a 700 nm fiber to form each chromatid (b) a: P. Motta & T. Naguro/SPL/Science Source 700 nm 6 hromosome at the midpoint (metaphase) of cell division
Fig. 4.5 opyright McGraw-Hill Education. Permission required for reproduction or display. Kinetochore entromere Sister chromatids (a) (b) b: Biophoto Associates/Science Source 700 nm
Table 4.1
Table 4.2
Fig. 4.6 opyright McGraw-Hill Education. Permission required for reproduction or display. Gene (DNA) 1 Transcription Pre-mRNA Intron Exon A B D E F 2 Splicing mrna 1 mrna 2 mrna 3 A D B D E A E F 3 Translation Protein 1 Protein 2 Protein 3
Fig. 4.7 opyright McGraw-Hill Education. Permission required for reproduction or display. Amino acid accepting end A U U A Anticodon
Fig. 4.8 1 mrna cap trna opyright McGraw-Hill Education. Permission required for reproduction or display. Pool of free Ribosomal amino acids subunits ATP ADP + Ribosome 2 trna binds an amino acid P i mrna mrna Polyribosome Protein trna released trna delivers amino acid to ribosome Met Ala Thr Nuclear pore Nucleus mrna GGG A Direction of ribosome movement E P A AUG GA GU odon UG AG GA Large ribosomal subunit Anticodon Small ribosomal subunit 3 Free protein Folding proteins 4 Ribosome assembly mrna Ribosome Direction of translation Protein Growing protein Rough endoplasmic reticulum Transport vesicle
Fig. 4.9 opyright McGraw-Hill Education. Permission required for reproduction or display. Protein mrna Ribosomes 50 nm Dr. Elena Kiseleva/Science Source
Fig. 4.10 opyright McGraw-Hill Education. Permission required for reproduction or display. 1 DNA double helix TA G T TG GTA T AT 2 Seven base triplets on the template strand of DNA AUG Start GG GGA AG AU GAG UGA Stop 3 The corresponding codons of mrna transcribed from the DNA triplets UA G U UG GUA U 4 The anticodons of trna that bind to the mrna codons Met Ala Gly Thr His Glu 5 The amino acids carried by those six trna molecules Met Ala Gly Thr His Glu 6 The amino acids linked into a peptide chain
Fig. 4.11 opyright McGraw-Hill Education. Permission required for reproduction or display. 1 Protein formed by ribosomes on rough ER. 2 Protein packaged into transport vesicle, which buds from ER. Nucleus 3 Transport vesicles fuse into clusters that unload protein into Golgi complex. 4 Golgi complex modifies protein structure. 5 Golgi vesicle containing finished protein is formed. Ribosomes 6 Secretory vesicles release protein by exocytosis. lathrin-coated transport vesicle Golgi complex Rough ER Lysosome
Table 4.3
Fig. 4.12 opyright McGraw-Hill Education. Permission required for reproduction or display. Prolactin Prolactin receptor 1 7 asein Exocytosis 2 ATP ADP + 6 P i Secretory vesicles Golgi complex Regulatory Protein (transcription activator) Rough endoplasmic reticulum 3 5 4 mrna for casein asein gene RNA polymerase
Fig. 4.13 opyright McGraw-Hill Education. Permission required for reproduction or display. Interstitial cell of testis DNA 1 DNA codes for mrna (transcription). From pituitary Luteinizing hormone 3 When testosterone is needed, luteinizing hormone stimulates production of a second messenger within the cell. Second messenger mrna 2 In the cytoplasm, Translation mrna codes for the synthesis of an enzyme (translation). Enzyme H 3 H 3 H 3 4 The second messenger activates the dormant enzyme. Activated enzyme OH HO holesterol 5 The enzyme converts cholesterol to testosterone. O Testosterone Secreted 6 Testosterone is secreted from the cell and exerts various anatomical, physiological, and behavioral effects.
Fig. 4.15 opyright McGraw-Hill Education. Permission required for reproduction or display. Metaphase Anaphase G 2 Second gap phase Growth and preparation for mitosis G 1 First gap phase Growth and normal metabolic roles S Synthesis phase DNA replication
Fig. 4.14 opyright McGraw-Hill Education. Permission required for reproduction or display. Incoming nucleotides Old strand New strand Daughter DNA (e) Parental DNA (b) Replication fork DNA polymerase (a) Key DNA helicase A T G (c) Gap in replication (d) DNA ligase
Fig. 4.16 opyright McGraw-Hill Education. Permission required for reproduction or display. 1 Prophase hromosomes condense and nuclear envelope breaks down. Spindle fibers grow from centrioles. entrioles migrate to opposite poles of cell. 1 Aster 2 2 Metaphase hromosomes lie along midline of cell. Some spindle fibers attach to kinetochores. Fibers of aster attach to plasma membrane. 3 Spindle fibers entriole hromatids Kinetochore 3 Anaphase entromeres divide in two. Spindle fibers pull sister chromatids to opposite poles of cell. Each pole (future daughter cell) now has an identical set of genes. 4 4 Telophase hromosomes gather at each pole of cell. hromatin decondenses. New nuclear envelope appears at each pole. New nucleoli appear in each nucleus. Mitotic spindle vanishes. Nuclear envelope re-forming Daughter cells in interphase leavage furrow hromatin Nucleolus (1-4): Ed Reschke
Fig. 27.13 opyright McGraw-Hill Education. Permission required for reproduction or display. Meiosis I (first division) Meiosis II (second division) Early prophase I hromatin condenses to form visible chromosomes; each chromosome has 2 chromatids joined by a centromere. hromosome Nucleus entromere entrioles Prophase II Nuclear envelopes disintegrate again; chromosomes still consist of 2 chromatids. New spindle forms. Mid- to late prophase I Homologous chromosomes form pairs called tetrads. hromatids often break and exchange segments (crossing-over). entrioles produce spindle fibers. Nuclear envelope disintegrates. Metaphase I Tetrads align on equatorial plane of cell with centromeres attached to spindle fibers. Tetrad rossing-over Spindle fibers entromere hromatid Equatorial plane Metaphase II hromosomes align on equatorial plane. Anaphase II entromeres divide; sister chromatids migrate to opposite poles of cell. Each chromatid now constitutes a single-stranded chromosome. Anaphase I Homologous chromosomes separate and migrate to opposite poles of the cell. Telophase II New nuclear envelopes form around chromosomes; chromosomes uncoil and become less visible; cytoplasm divides. Telophase I New nuclear envelopes form around chromosomes; cell undergoes cytoplasmic division (cytokinesis). Each cell is now haploid. leavage furrow Final product is 4 haploid cells with single-stranded chromosomes.
Fig. 27.14 opyright McGraw-Hill Education. Permission required for reproduction or display. ross section of seminiferous tubules Lumen of seminiferous tubule Sperm 5 Spermiogenesis Spermatid n n n n 4 Meiosis II Secondary spermatocyte n n 3 Blood testis barrier Primary spermatocyte Nurse cell Meiosis I 2n 2 Type B spermatogonium 2n Tight junction Type A spermatogonium Basement membrane of seminiferous tubule 2n 1
Fig. 4.17 opyright McGraw-Hill Education. Permission required for reproduction or display. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 XX female XY male Science Source
Fig. 4.18 opyright McGraw-Hill Education. Permission required for reproduction or display. (a) left chin, c Uncleft chin cc c 15 Homozygous, 16 17 cleft chin c Heterozygous, cleft chin c c Heterozygous, cc Homozygous, cleft chin uncleft chin 21 22 XX female (b) a (left): Brad Barket/Getty Images; a (right): Kurt Krieger/orbis; b (top left, top right, bottom left): Brad Barket/Getty Images; b (bottom-right): Kurt Krieger/orbis
Fig. 4.19 opyright McGraw-Hill Education. Permission required for reproduction or display. Gene 1 Gene 2 Phenotype (eye color) 13 Gene 3 (top): Getty Images RF; (middle): Anthony Saint James/Getty Images RF; (bottom): JupiterImages/omstock/Getty Images RF