Transcript DNA, RNA and Protein

Macromolecules
Building Complex
Molecules That Comprise
Living Things
Organic Macromolecules
Contain Carbon
Question: How many
electrons does carbon need
to fill its outer energy level?
 Answer: Four
Therefore, each carbon atom can
four covalent bonds with
make ____
other types of atoms or additional
carbons.
In a triple bond,
carbons share three
pairs of electrons
In a double bond,
carbons share two
pairs of electrons
Carbon Atoms Bind to Functional Groups
Organic Molecules Can Exist as Isomers
Structural Isomers have the same atoms
in different bonding relationships
Stereoisomers have
different spatial positioning
for the same bonding relationships
Macromolecules: Polymers
Made of Repeating Monomers
Macromolecule
Carbohydrates
Lipids
Proteins
Monomer Unit
Nucleic Acids
Nucleotides
Sugars
Fatty acids
Amino acids
Synthesis and Breakdown of
Macromolecules
Condensation
or Dehydration
Synthesis
Hydrolysis
Removal of water to add
monomer units
Addition of OH and H
groups of water to break
a bond between
monomers
Dehydration Synthesis / Hydrolysis
Dehydration Synthesis
Hydrolysis
Nucleic Acid
Structure and Function
Information Flow From DNA
replication
(prior to
cell division)
Gene: sequence
of DNA that codes
for a protein
DNA
transcription
RNA
translation
Protein
(ongoing
cellular
metabolism)
DNA and RNA Structure
DNA
RNA
Primary
Structure
Chain of
nucleotides
Chain of
nucleotides
Secondary
Structure
Double helix Single
folded chain
Three Parts of Nucleotide Structure
NH2
Phosphate Group
OH
HO
P
O
HC
O
N C
C
N
CH
C
N
CH2 O
N
Deoxyribose
Nitrogenous
H or H
Base
(1
of
5)
Ribose
H
H
OH
H
5-Carbon Sugar
DNA and RNA Structure
DNA
Purine
bases
Pyrimidine
bases
5-carbon sugar
Adenine (A)
Guanine (G)
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Cytosine (C)
Uracil
(U)
deoxyribose
OH
Phosphate
RNA
PO4
H
ribose
OH
OH
PO4
Nucleotide Chain
Nucleotides are joined
together by dehydration
synthesis
The phosphate of one
nucleotide is joined to
sugar of next
nucleotide, forming a
“sugar-phosphate
backbone”
3’ end
A
C
G pairs with C
T
A
A
T
G
C
A
T
3’ end
has free sugar
G
5’ end
has free phosphate
•Two nucleotide
chains
•In opposite
orientations
•Held together
by hydrogen
bonds
•Twisted into a
helix
T
DNA Structure
A pairs with T
5’ end
T
C
A
G
DNA Secondary Structure
The Double Helix
• Two polynucleotide chains are
wound together
• Bases are located inside the helix
• Sugar-phosphate groups are on
the outside as a “backbone”
• Bases are arranged like rungs on
a ladder, perpendicular to the
“backbone”
• 10 base pairs per turn of the helix
DNA Replication
•DNA chains separate
•Each chain is used
as a pattern to
produce a new chain
•Each new DNA helix
contains one “old”
and one “new” chain
Transcription = Production of RNA Using
DNA as a Template
•DNA chains separate
•ONE DNA chain is used
as a pattern to produce
an RNA chain
•RNA chain is released
and the DNA chains
reform the double-helix
In DNA In RNA
A
U
T
A
G
C
C
G
RNA Secondary Structure
Single, Folded Chain
• Each RNA has a
unique structure
based on its
nucleotide sequence
• RNA-RNA Base
Pairing Rules
– A pairs with U
– G pairs with C
• Can link
– bases in proximity
– distant base
sequences
Functions of Nucleotides and Nucleic Acids
DNA
RNA
Hereditary Material, specifies
protein sequences
Intermediate in protein production
Ribozymes RNA catalysts
ATP
GTP
cAMP
(cyclic AMP)
Energy transfer
Energy transfer
Activator/Inhibitor in Signal
Transduction
Secondary messenger in Signal
Transduction