DNA: STRUCTURE

1
DNA STRUCTURE FUNCTION

• I. DNA FUNCTIONS
• A. DIRECTS THE SYNTHESIS OF PROTEINS

2

• B. CARRIES GENETIC INFORMATION FROM GENERATION
  TO GENERATION

3
II. DNA STRUCTURE

• A. MACRO STRUCTURE LOOKS LIKE A
  TWISTED LADDER OR DOUBLE HELIX

4

• B. MICRO - A POLYMER MADE OF NUCLEOTIDE MONOMERS

5
SIDES OF THE LADDER ARE MADE OF SUGAR PHOSPHATE
S
S
P
P
S
S
P
P
S
S
6
LADDER RUNGS ARE MADE OF FOUR DIFFERENT NITROGEN
BASES
deoxyribose sugars
A
T
S
S
P
P
C
S
G
S
P
P
S
S
T
A
7
Building DNA Building Blocks
8
NITROGEN BASES ARE
ADENINE
GUANINE
CYTOSINE
THYMINE
9
BONDING SPECIFICITY
III.
ADENINE BONDS WITH THYMINE CYTOSINE BONDS WITH
GUANINE
THIS CHEMICAL SPECIFICITY (A-T, G-C) ENSURES
FAITHFUL REPLICATION
10
CHROMOSOMES DNA
IV.
DNA WRAPPED AROUND PROTEINS CALLED HISTONES MAKE
UP CHROMOSOMES
11
V. PROTEINS

• MAKE UP THE STRUCTURAL COMPONENTS AND REGULATORY
  CHEMICALS OF LIVING THINGS

12
A. STRUCTURAL PROTEINS

• ACTIN, MYOSIN IN MUSCLE
• COLLAGEN IN CONNECTIVE TISSUE
• SKIN PROTEINS - KERATIN
• BLOOD PROTEINS - HEMOGLOBIN,CLOTTING FACTOR
• CYTOSKELETON PROTEINS

13
B. FUNCTIONAL PROTEINS

• 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

14
C. HORMONES

• GROWTH HORMONE
• ADRENALINE
• INSULIN
• OXYTOCIN
• FOLLICLE STIMULATING HORMONE
• PITUITARY HORMONE
• PROLACTIN
• ADRENOCORTICOTROPIC HORMONE

15
D. IMMUNOLOGICAL PROTEINS

• ANTIBODIES,
• INTERFERONS,
• INTERLEUKINS,
• COMPLEMENT

16
VI. DNA REPLICATION

• OCCURS PRIOR TO MITOSIS
• DURING THE S PHASE OF INTERPHASE
• INVOLVES THE ENZYMES DNA HELICASE, AND DNA
  POLYMERASE

17
STAGES OF DNA REPLICATION

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

18

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

19
(No Transcript)
20
(No Transcript)