Download Structure of Nucleic Acids

Chemistry of Life
Inorganic molecules: Are not
made of both C AND H
Organic Molecules: Contain C
AND H; may have other elements
- hydrocarbons: organic molecules
that have ONLY C and H
Compounds of the Cell:
Water
Lipids
Minerals Carbohydrates
Proteins
Nucleic
Acids
WATER:
 Body is 65- 75% on average
Functions of water:
 Solvent
 Medium
 Moistens Surfaces
 Temperature
Regulation
 Cushion
 Transportation
 Lubrication
 Hydrolysis
 Sense Organs
Minerals
Main Functions:
- help maintain fluid balance
- act as a pH buffer
- aid in structure of cells and body
- allow nervous system to work
Examples: Na, Cl, K, P, Ca, Fe
The 4 major compounds in the cell are
all types of Macromolecules
Macro = BIG
First we build a smallish organic
molecule.
Then we link many of
those together
building a chain
Single units are called monomers
Chain of units is called polymer
Single units are called monomers
Chain of units is called polymer
Dehydration synthesis: chemical
reaction that joins two or more
monomers to form polymers plus a
water molecule (Building)
Dehydration synthesis:
- Step 1: begin with at least two
unlinked monomers
HO
OH
+
HO
OH
Dehydration synthesis:
- Step 2: Remove an H from monomer
1 and an OH from monomer 2
- The H and OH combine to form
water
O H + HO
OH
HO
HOH = H2O
Dehydration synthesis:
- Step 3: connect what is left of the
monomers
HO HO
+
O O
OH
OH + H2O
Dehydration synthesis:
Final products:
1 Growing chain
- (beginnings of a polymer)
1 Water molecule
HO
O
OH
+ H2O
Hydrolysis: Chemical reaction that
uses water to separate polymers into
monomers. (Break apart)
- Exactly the opposite of Dehydration
synthesis
Hydrolysis:
- Step 1: Start with polymer and 1
water molecule
HO
O
OH
+ H2O
Hydrolysis:
- Step 2: Break water into 1 H and 1
OH
- Add the H to one monomer and the
OH to the other;
HO
O
H HO
OH
Hydrolysis:
- Step 3: Split the bond between
monomers
HO
OH
OH
HO
Hydrolysis:
- Step 3: Split the bond between
monomers
HO
OH
HO
OH
Hydrolysis:
- Final Product:
Two unlinked monomers
HO
OH
HO
OH
CARBOHYDRATES (CHO)
“The Sugars”
Formulas:
Molecular:
C6H12O6
Straight
Chain:
Structural:
CARBOHYDRATES
Monomer of carbs: monosaccharide
- means “one sweet unit”
- these are the simple sugars
- made of C, H and O in a 1:2:1 ratio
CARBOHYDRATES
Disaccharides: “double sugars”;
- two monosaccharides linked together
Polysaccharides: 3 or more
monosaccharides linked together;
CARBOHYDRATES
Examples of Carbs:
Sugars: glucose, ribose, fructose,
sucrose, lactose
Starch: Amylose
Fiber: Cellulose
CARBOHYDRATES
Function of Carbs:
1.Simple FAST Energy for the cell
• monosaccharides = instant energy
• polysaccharides = short term
storage of energy
- Plants use starch
- Animals use glycogen
CARBOHYDRATES
Function of Carbs
2. Are used for building structures
Plants: cellulose is used for cell wall
Animals: chitin is used for exoskeleton
Chitin and cellulose are
polysaccharides
Lipids - Fats
No true monomer – can’t make long
chains;
One type of Lipid molecule is called a
Triglyceride and is made of:
1 glycerol molecule + 3 Fatty Acids
Lipids
Structure of Triglyceride:
- 1 glycerol + 3 FA’s
Lipids
Lipids
Structure of Lipids:
- 1 glycerol + 3 FA’s  Fat
Lipids
Building or breaking apart a lipid uses
same reactions as carbs:
Dehydration synthesis is used to connect
each fatty acid (three total) to the glycerol
- three water molecules are made
Hydrolysis is used to break each fatty acid
off of the glycerol
- three water molecules are used
Different types of fatty acids
Different types of fatty acids
Phospholipid (almost a triglycerid)
Polar “head” and
nonpolar tail
Crucial for
forming a
membrane!!
Cholesterol (a steroid)
Ring structure is characteristic of all steroids
including reproductive hormones
Lipids
 Examples: fats, oils, waxes,
steroids (including cholesterol)
 Do not dissolve in water
Lipids
Functions of lipids:
1. Reserve, long term energy storage
2. Structure: plasma membrane of all
cells and parts within cells are made
of phospholipids;
3. Insulation
4. Produce reproductive hormones
Dieting:
Are fats and “carbs” really evil??
Why has society become anti-carb?
Is Atkins or the South Beach diet really
good for you??
Proteins
Monomer: Amino acid
Amino end
-NH2
O
Carboxyl end
H H
-COOH
H N C C OH
R
Variable R
group
Proteins
There are 20 different amino acids
- all have same amino end, carboxyl
end and central carbon
- EACH has a different R group
Amino acids are made of:
C, H, O, N, and S (in R group of some)
Amino acids are linked together to form
polypeptides
Uses the Same chemical reactions
O
O
H H
H N C C OH
R
+
H H
H N C C OH
R
Amino acids are linked together to form
polypeptides
Step 1: remove H and OH
O
O
H H
HN C C
+
H H
N C C OH
R
R
H OH
Amino acids are linked together to form
polypeptides
Step 2: Link rest of monomers together
O
O
H H
H H
H N C C N C C OH
R
R
H OH
Amino acids are linked together to form
polypeptides
Product: growing chain + 1 water molecule
O
O
H H
H H
H N C C N C C OH + H OH
R
R
New bond; Called peptide bond
Amino acids are linked together to form
polypeptides
To become a “protein” a polypeptide must
be folded into a unique 3D shape
Only proteins have a “job”.
Polypeptides don’t “work” until folded
Examples of proteins and their function
1.Cartilage: builds part of our body;
structural protein
2.Hormones: chemical messengers
3.Enzymes: speed up chemical
reactions; needed for ALL reactions
4.Antibodies: fight disease
Nucleic Acids
Monomer of nucleic acid: nucleotide
Nucleotides have three parts:
 Sugar: ribose or deoxyribose
 Phosphate group: PO3
 Nitrogen Base – one of 5 different
kinds
Structure of Nucleic Acids
Elements of NA: C,H,O,N and P
P
CH2
o
Base
H H
H
H
OH H
P = Phosphate = H2PO3
Nucleic Acids
Function of nucleic acids:
- “info molecules”;
- hold the information on
how to make all proteins
- Essentially tell your body
how to do everything
Nucleic Acids
Only two kinds:
1. DNA: Deoxyribose
Nucleic Acid
- “hard drive”of the cell;
- holds the directions to
make proteins
- MASTER copy of all
the information
Nucleic Acids
Only two kinds:
2. RNA: Ribose Nucleic
Acid;
- transfers info from DNA
to ribosomes (protein
factories)
- temporary copy of one
recipe at a time
Differences between RNA and DNA
RNA:
 Single stranded Helix
 Ribose is the sugar in all RNA
nucleotides
Choice of nitrogen bases:
Adenine, Uracil, Guanine, Cytosine
Differences between RNA and DNA
DNA:
 Double stranded Helix
 Deoxyribose is the sugar in all
DNA nucleotides
Choice of nitrogen bases:
Adenine, Thymine, Guanine, Cytosine
Structure of Nucleic Acids
- Build/broken down using same
reactions!!
P
CH2
o
Base
H H
H
H
OH H
P = Phosphate = H2PO3
P
CH2
o
Base
H H
H
H
OH H
H20
P
CH2
o
Base
H H
-
H2PO33
P = HPO
H
H
OH H
P
CH2
o
Base
H H
H
H
P
H
CH2
o
Base
H H
H
H
OH H
P
Chain forms by
Base
connecting
the
CH2 o
sugar
of
one
NT
H
H
H
H
to the Phosphate
H
Base of the next
P CH2 o
Forms PhosphateH H
H
H
sugar backbone
OH H