Transcript DNA (Deoxyribonucleic Acid)

Organic
Chemistry:
Nucleic Acids
Review of
ORGANIC CHEMISTRY

Definition:
– Contains

CARBON (C)
– Can also contain

HYDROGEN (H) AND OXYGEN (O)
– Living things can add

NITROGEN, PHOSPHOROUS, SULFUR AND
OTHER SUBSTANCES
– Create Macromolecule:

built from smaller organic compounds.
Organic Chemistry

4 kinds of Organic
Macromolecules
1.
2.
3.
4.
Carbohydrates
Lipids
Nucleic Acids
Proteins
NUCLEIC ACIDS
Named for where they
were first found:
The Nucleus

Three types that we will be studying
1. DNA (Deoxyribnucleic Acid)
2. RNA (Ribonucleic Acid)
3. ATP (Adenosine Triphosphate)
NUCLEIC ACIDS

Contain the elements:
 Carbon
 Hydrogen
 Oxygen
 Nitrogen
 Phosphorous
Structure of Nucleic Acids:


Definition:
– small, repeating
chain of
nucleotides.
Nucleotide:
* 5 carbon sugar
* phosphate
* nitrogenous base
DNA
Deoxyribonucleic Acid
 Stores hereditary information in the cell
that directs the cell’s activities
and determines a cell’s
characteristics.
 Supercoiled into
chromosomes
– DNA makes up GENES
DNA Nucleotide
3 separate components
DNA Nucleotide Structure:
component #1
1.
5 carbon sugar
“Deoxyribose”
– “de” means without…

With one fewer
oxygen than ribose
sugar
DNA Nucleotide Structure:
component #2
Phosphate
3PO4

Carries a negative
charge.
DNA Nucleotide Structure:
component #3
Nitrogenous
Base

2 possible types
– Purines:
 Adenine and Guanine
 Double ringed
– Pyrimidines:
 Thymine and Cytosine
 Single ringed
 DNA does not contain
Uracil
X
DNA Nucleotide
Sugar
Phosphate
Base
3-D Structure of DNA

The nucleotides are
connected together
into two long chains
hooked together in
the middle to create
a ladder.

Double Stranded
– Sides: alternating
sugar and
phosphate units
– Rungs: Purine
and pyrimidine
held together by
hydrogen bond.
Complementary bonding
between the bases in the rungs

weak hydrogen bonds
– Purine=Pyrimidine
– *Adenine= Thymine
A-T
– *Guanine= Cytosine
G-C
3-D Structure of DNA

Double Stranded +
Twisted
DOUBLE HELIX:

“Spiral Staircase”

“Twisted Ladder”
3-D Structure of DNA
The sequence of bases on one strand
determines the sequence of bases on the
other strand…”complementary.”
Ex.
•TCGAACT on one strand dictates
that the other strand will be
 AGCTTGA
Nucleic Acids

We will cover RNA later and we have
already studied ATP
So What is ATP
= Adenosine TriPhosphate
Energy Currency of the Cell
• Cells require a molecule that stores smaller quantities of
energy to be used in individual reactions (of metabolism)
• And can be used over and over again.
• This molecule acts as the short-term energy currency of the
cell.
ATP Nucleotide
3 separate components
ATP =
Adenosine Triphosphate:
• Consists of
• Nitrogenous Base: Adenine
• Sugar: Ribose
(these 2 molecules make up “Adenosine”)
• 3 Phosphate groups
ATP Nucleotide Structure:
component #1
Nitrogenous
Base
• Adenine
ATP Nucleotide Structure:
component #2
1. 5 carbon sugar: Ribose
ATP Nucleotide Structure:
component #3
3 Phosphates
PO43• Carries a negative
charge.
ATP Nucleotide
Sugar
3 Phosphates
Base
• The bond linking the last two phosphates onto the first are highenergy bonds…very, very UNSTABLE!
• These bonds are broken by hydrolysis
• High energy because large amounts are given off when they are
broken off
• This is where the energy from the bonds in glucose are stored
during cellular respiration.
ATP + H2O  ADP + P + energy
ADP = Adenosine Diphosphate)
• As the ATP breaks down by losing a phosphate,
the energy released is used for other reactions in
the cell that require energy (metabolism!).
• The bond that is broken is the high energy bond between
the last two phosphates.
• To go from ADP back ATP
• phosphate (found in the cytoplasm) is joined to the ADP.
• This is done through…
RESPIRATION: When energy is released from the bonds of
glucose as it is broken down.
ATP is the Product of Cellular
Respiration!!!!
 As glucose is broken
down:
 energy is released from
the bonds of the glucose
and
 becomes part of the
bond between
 the 2nd and 3rd
phosphates.