DNA STRUCTURE FUNCTION I DNA FUNCTIONS A DIRECTS

DNA: STRUCTURE & FUNCTION I. DNA FUNCTIONS: A. DIRECTS THE SYNTHESIS OF PROTEINS

• B. CARRIES GENETIC INFORMATION FROM GENERATION TO GENERATION

II. DNA STRUCTURE n A. MACRO STRUCTURE LOOKS LIKE A TWISTED LADDER OR “DOUBLE HELIX”

n B. MICRO - A POLYMER MADE OF NUCLEOTIDE MONOMERS

SIDES OF THE LADDER ARE MADE OF SUGAR & PHOSPHATE S S P P S S

LADDER RUNGS ARE MADE OF FOUR DIFFERENT NITROGEN BASES S A T S P P S C G S P P S T A S deoxyribose sugars

Building DNA Building Blocks

NITROGEN BASES ARE: ADENINE GUANINE CYTOSINE THYMINE

III. BONDING SPECIFICITY ADENINE BONDS WITH THYMINE CYTOSINE BONDS WITH GUANINE THIS CHEMICAL SPECIFICITY (A-T, G-C) ENSURES FAITHFUL REPLICATION

IV. CHROMOSOMES & DNA: DNA WRAPPED AROUND PROTEINS CALLED HISTONES MAKE UP CHROMOSOMES

V. PROTEINS MAKE UP THE STRUCTURAL COMPONENTS AND REGULATORY CHEMICALS OF LIVING THINGS

A. STRUCTURAL PROTEINS ACTIN, MYOSIN IN MUSCLE n COLLAGEN IN CONNECTIVE TISSUE n SKIN PROTEINS - KERATIN n BLOOD PROTEINS HEMOGLOBIN, CLOTTING FACTOR n CYTOSKELETON PROTEINS n

B. FUNCTIONAL PROTEINS n ENZYMES - ATPase, ATPsynthetase, DNA helicase, DNA polymerase, DNAase, carboxylases, lipases, proteases, nucleases, amylase, pepsin, alcohol dehydrogenase, enzymes involved in respiration, photosynthesis, cell division, and all biological processes

C. HORMONES n n n n GROWTH HORMONE ADRENALINE INSULIN OXYTOCIN FOLLICLE STIMULATING HORMONE PITUITARY HORMONE PROLACTIN ADRENOCORTICOTROPIC HORMONE

D. IMMUNOLOGICAL PROTEINS ANTIBODIES, n INTERFERONS, n INTERLEUKINS, n COMPLEMENT n

VI. DNA REPLICATION OCCURS PRIOR TO MITOSIS n DURING THE S PHASE OF INTERPHASE n INVOLVES THE ENZYMES DNA HELICASE, AND DNA POLYMERASE n

STAGES OF DNA REPLICATION DNA UNZIPS ITSELF, ENZYME INVOLVED IS DNA HELICASE n ENZYME DNA POLYMERASE JOINS FREE NUCLEOTIDES TO EACH SINGLE STRAND. THIS IS DONE ACCORDING TO THE CHEMICAL SPECIFICITY OF A-T, G-C. n

n. RESULTS IN TWO IDENTICAL DAUGHTER STRANDS WHICH ARE IDENTICAL TO THE PARENT STRAND