Download chapter-22

Human egg and sperm.
Chapter 22. Nucleic Acids
Sections
Chemistry 121 Winter 2009 LA Tech
Chapter 22-1
Chapter 22. Nucleic Acids-Sections
22.1 Types of Nucleic Acids
22.2 Nucleotides: Building Blocks of Nucleic Acids
22.3 Primary Nucleic Acid Structure
22.4 The DNA Double Helix
22.5 Replication of DNA Molecules
22.6 Overview of Protein Synthesis
22.7 Ribonucleic Acids
Chemistry at a Glance: DNA Replication
22.8 Transcription: RNA Synthesis
22.9 The Genetic Code
22.10 Anticodons and tRNA Molecules
22.11 Translation: Protein Synthesis
22.12 Mutations
Chemistry at a Glance: Protein Synthesis
22.13 Nucleic Acids and Viruses
22.14 Recombinant DNA and Genetic Engineering
22.15 The Polymerase Chain Reaction
22.16 DNA Sequencing
Chemistry 121 Winter 2009 LA Tech
Chapter 22-2
Adenine, a nucleic acid base
Molecule of Adenine, a
nitrogen-containing
heterocyclic base present
in both RNA and DNA.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-3
Nucleic acid bases
Two purine bases and
three pyrimidine
bases are found in
the nucleotides
present in nucleic
acids.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-4
Nucleotides
Table 22.1
Chemistry 121 Winter 2009 LA Tech
Chapter 22-5
Nucleic acid bases
Chemistry 121 Winter 2009 LA Tech
Chapter 22-6
Lipids cont’d
Fig. 22.3
The general structure of a nucleic acid in terms of
nucleotide subunits.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-7
Backbone structure for nucleic acid
(a) The generalized
structure of a nucleic
acid. (b) The specific
backbone structure
for a
deoxyribonucleic acid
(DNA). (c) The
specific backbone
structure for a
ribonucleic acid
(RNA).
Chemistry 121 Winter 2009 LA Tech
Chapter 22-8
DNA Fragment
A four-nucleotidelong segment of DNA.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-9
Protiens and DNA Comparison
A comparison of the primary structures of nucleic acids
and proteins.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-10
DNA double helix
A schematic drawing
of the DNA double
helix that emphasizes
the hydrogen
bonding between
bases on the two
chains.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-11
Hydrogen bonding in Base Pairs
Hydrogen bonding
possibilities
Chemistry 121 Winter 2009 LA Tech
Chapter 22-12
DNA replication
Chemistry 121 Winter 2009 LA Tech
Chapter 22-13
DNA Replication
One strand of DNA grows continuously in the direction of
the unwinding, and the other grows in the opposite
direction.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-14
DNA replication at multiple sites
DNA replication usually occurs at multiple sites within a molecule,
and the replication is bidirectional from these sites.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-15
What in Common Twins Have?
Identical twins share
identical physical
characteristics
because they
received identical
DNA from their
parents.
© Erica Stone / Peter Arnold, Inc.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-16
DNA replication… cont’d
Chemistry 121 Winter 2009 LA Tech
Chapter 22-17
RNA hairpin loop
A hairpin loop is produced when a single-stranded
RNA doubles back on itself and complementary
base pairing occurs.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-18
Types of RNA
Chemistry 121 Winter 2009 LA Tech
Chapter 22-19
Transcription of DNA to form RNA
The transcription of DNA to form RNA involves an unwinding
of a portion of the DNA double helix.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-20
Exons and Introns of RNA
Heterogenous nuclear RNA contains both exons and introns.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-21
Exons and Introns of RNA cont’d
An hnRNA molecule containing four exons.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-22
Codes for Amino Acids
Chemistry 121 Winter 2009 LA Tech
Chapter 22-23
tRNA molecule
A tRNA molecule
Chemistry 121 Winter 2009 LA Tech
Chapter 22-24
Aminoacyl-tRNA synthetase
An aminoacyl-tRNA synthetase has an active site for tRNA and a
binding site for the particular amino acid that is to be attached to
that tRNA.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-25
Anticodon and Codon
The interaction
between anticodon an
codon.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-26
Ribosome Structure
Ribosomes have structures that contain two subunits.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-27
Protein Synthesis: Initiation
Initiation of protein synthesis begins with the formation of an
initiation complex.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-28
Protein Synthesis: Translation
The process of translation that occurs during protein synthesis.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-29
Effects of Antobiotics
Chemistry 121 Winter 2009 LA Tech
Chapter 22-30
Polysome
Several ribosomes can simultaneously proceed along a single
strand of mRNA. Such a complex of mRNA and ribosomes is
called a polysome.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-31
Protien Synthesis Summary
Chemistry 121 Winter 2009 LA Tech
Chapter 22-32
Influenza virus.
Image of an influenza
virus.
NIBSC / SPL / Photo Researchers
Chemistry 121 Winter 2009 LA Tech
Chapter 22-33
Recombinant DNA
Recombinant DNA is made by inserting a gene obtained from DNA of
one organism into the DNA from another kind of organism.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-34
Cleaving DNA patterns using restriction enzymes
Cleavage patterns resulting from the use of a restriction enzyme that
cleaves DNA between G and A bases.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-35
“sticky ends” of recombnants
The “sticky ends” of the cut plasmid and the gene are
complementary and combine to form recombinant DNA.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-36
Polymerase chain reaction process
Chemistry 121 Winter 2009 LA Tech
Chapter 22-37
Polymerase chain reaction process
Chemistry 121 Winter 2009 LA Tech
Chapter 22-38
DNA sequencing
Selected steps in the DNA sequencing procedure for the 10-base DNA
segment 5’ AGCAGCTGGT 3’.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-39
Nucleic Acids - RNA and DNA
Nucleic acid is a complex, high-molecular-weight
biochemical macromolecule composed of
nucleotide chains that convey genetic
information.
The most common nucleic acids are
deoxyribonucleic acid (DNA) and ribonucleic acid
(RNA).
Nucleic acids are found in all living cells and
viruses.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-40
Nucleotides
Nucleotides are the building blocks of DNA and
RNA.
• Serve as molecules to store energy and reducing
power.
• The three major components in all nucleotides are
phosphoric acid, pentose (ribose and deoxyribose),
and a base (purine or purimidine).
• Two major purines present in nucleotides are
adenine (A) and guanine (G), and three major
purimidines are thymine (T), cytosine (C) and uracil
Chemistry 121 Winter 2009 LA Tech
Chapter 22-41
(U).
Chemistry 121 Winter 2009 LA Tech
Chapter 22-42
Ribonucleotides
Adenosine triphosphate (ATP) and guanosine triphosphate
(GTP), which are the major sources of energy for cell
work.
- The phosphate bonds in ATP and GTP are high-energy
bonds.
- The formation of phosphate bonds or their hydrolysis is
the primary means by which cellular energy is stored or
used.
nicotinamide adenine dinucleotide (NAD) and nicotinamide
adenine dinucleotide phosphate (NADP).
The two most common carriers of reducing power for
biological oxidation-reduction reactions.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-43
Deoxyribonucleic Acid (DNA)
Deoxyribonucleic acid (DNA) is formed by
condensation of deoxyribonucleotides.
3
The nucleotides are linked together
between the 3’ and 5’ carbons’
successive
pentose rings by phosphodiester
bonds
Chemistry 121 Winter 2009 LA Tech
5
Chapter 22-44
Deoxyribonucleic Acid (DNA)
- DNA is a very large threadlike macromolecule
(MW, 2X109 D in E. coli).
- DNA contains adenine (A) and guanine (G),
thymine (T) and cytosine (C).
- DNA molecules are two stranded and have a
double-helical three-dimensional structure.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-45
DNA Double-helical Structure
Chemistry 121 Winter 2009 LA Tech
Chapter 22-46
Double Helical DNA Structure
The main features of double helical DNA structure are
as follows: .
- The phosphate and deoxyribose units are on the
outer surface, but the bases point toward the chain
center. The plane of the bases are perpendicular to
the helix axis.
- The diameter of the helix is 2 nm, the helical
structure repeats after ten residues on each chain, at
an interval of 3.4 nm.
- The two chains are held together by hydrogen
bonding between pairs of bases.
Adenine (A) - thymine (T), guanines (G) - cytosine
(C).
- The sequence of bases along a DNA strand is not
restricted
any way and carries genetic
Chemistry
121 Winter 2009 in
LA Tech
Chapter 22-47
information, and sugar and phosphate groups
DNA Replication
Regeneration of DNA from original DNA
segments.
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter14/animations.html#
http://www.ncc.gmu.edu/dna/repanim.htm
Chemistry 121 Winter 2009 LA Tech
Chapter 22-48
http://www.lewport.wnyric.org/jwanamaker/animations/DNA%20Replication%20-%20long%20.htm
DNA Replication
- DNA helix unzips and forms two separate
strands.
- Each strand will form a new double strands.
- The two resulting double strands are identical,
and each of them consists of one original and
one newly synthesized strand.
- This is called semiconservative replication.
- The base sequences of the new strand are
complementary to that of the parent strand.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-49
Ribonucleic Acid (RNA)
Ribonucleic acid (RNA) is formed by condensation
of ribonucleotides.
RNA is a long, unbranched macromolecule and may
contain 70 to several thousand nucleotides. RNA
molecule is usually single stranded.
RNA contains adenine (A), guanine (G), cytosine (C)
and uracial (U). A-U, G-C in some double helical
regions of t-RNA.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-50
Classification of RNA
According to the function of RNA, it can be classified
as:
Messenger RNA: (m-RNA) synthesized on chromosome
and carries genetic information to the ribosomes for
protein synthesis. It has short half-life.
Transfer RNA (t-RNA) is a relatively small and stable
molecule that carries a specific amino acid from the
cytoplasm to the site of protein synthesis on
ribosomes.
Ribosomal RNA (r-RNA) is the major component of
ribosomes, constituting nearly 65%. r-RNA is
responsible for protein synthesis.
Ribozymes are RNA molecules that have catalytic
properties.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-51
Summary of Nucleic Acids
Nucleotides are basic units of nucleic acids DNA and
RNA.
Nucleotides include pentose, base and phosphoric acid.
Bases include purine or pyrimidine.
Two major purines present in nucleotides are adenine (A)
and guanine (G), and three major pyrimidines are
thymine (T), cytosine (C) and uracil (U).
Ribonucleotides
- adenosine triphosphate (ATP) stores energy.
- NAD and NADP are important carriers of reducing
power.
Chemistry
121 Winter 2009 LA Tech
Chapter 22-52
Summary of Nucleic Acids
DNA
DNA contains genetic information.
DNA contains adenine (A) and guanine (G), and
thymine (T), and cytosine (C). A-T G-C
DNA has a double helical structure.
The bases in DNA carry the genetic
information.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-53
Summary of Nucleic Acids
RNA
• RNA functions as genetic information-carrying
intermediates in protein synthesis.
• It contains adenine (A) and guanine (G), and cytosine
(C) and uracil (U).
• m-RNA carries genetic information from DNA to the
ribosomes for protein synthesis.
• t-RNA transfers amino acid to the site of protein
synthesis
•
r-RNA is for protein synthesis.
Chemistry 121 Winter 2009 LA Tech
Chapter 22-54
Summary of Cell Construction
Biopolymers
protein
Carbohydrates
(polysaccharides)
DNA
RNA
lipids
subunit
bonds for
subunit
linkage
functions
Characteristic
three-D
structure
Chemistry
Chemistry 121 Winter 2009 LA Tech
55
Chapter 22-55