Download Structure of Nucleic Acids

Chemistry of Life
Bio A
Organic Molecules: molecules that
contain both C and H; can contain
other elements too;
- If they ONLY contain C and H
they are called hydrocarbons
Why can carbon make these long
chains?
C
Wants to share all its electrons
Therefore C can make up to 4
covalent bonds at a time!!
Draw each structure beside the
appropriate description. One of
the descriptions does NOT have a
structure shown
Organic Molecules: When you
cannot follow a line of carbons in a
molecule without “backtracking” the
molecule is branched.
2-methyl butane
Using skeletal structures
• Skeletal structures are used only for organic
molecules.
• Since all organic molecules contain C and
H, we only fill in things on the structure that
ARE NOT C or an H that is directly attach
to a C or H
• We draw a zigzag line to represent the line
of carbons. Each vertex or endpoint
signifies a carbon. LET’s try a few.
Draw skeletal structures of these
molecules
Inorganic molecules: molecules that
do not contain BOTH C and H
Some examples:
Compounds of the Cell:
Water
Lipids
Minerals Carbohydrates
Proteins
Nucleic
Acids
WATER: most essential inorganic
molecule
 Body is 65- 75% on average
More in fat or muscle??
More in Males or females??
Functions of water:
 Solvent: dissolves lots of stuff
 Medium: where the chemical
reactions happen
 Moistens Surfaces:
What if your lungs were dry?
Functions of water:
 Temperature Regulation
Example?
 Cushion
Brain in skull;
 Transportation
Moving molecules through the
blood
Functions of water:
 Lubrication
Joints; prevent bones from
scraping
 Hydrolysis
Using water to break apart large
molecules
Functions of water:
 Sense Organs
Eyes
Nose
Mouth
Minerals
Important minerals:
Iron
Phosphorous
Calcium
Iodine
Sodium
Chlorine
Potassium
Minerals
Function: help maintain fluid and electrolyte
balance;
- act as a pH buffer
- aid in structure of cells (body)
- Move nerve impulses
- Carry oxygen
- Regulate thyroid gland (and metabolism)
The organic molecules we will study
are known as Macromolecules
Macro = big
- made up of many small molecules
linked together to form one big
molecule
- small molecule = a monomer
- chain of small molecules = polymer
Nutritional Compounds
These Macromolecules are what
provide us with nutrition
They make up the “Calories” we eat
Calorie ( in science): 1 unit of thermal
(heat) energy
1 calorie (chemistry) is the amount of
energy it takes to raise the temperature
of 1 gram of water 1 degree Celsius
1 food calorie = 1000 chemistry calories
= 1 kilocalorie
So, 1 calorie of food has enough energy
to heat 1000g of water 1 degree.
Nutritional Label Handout
CARBOHYDRATES
(CHO)
Monomer: Monosaccharides:
simple sugars;
5 carbon or 6
Carbon rings
CARBOHYDRATES
(CHO)
Disaccharides: “double sugars”;
Polysaccharides: 3 or more single
sugars; huge chain molecules
How do they connect?
- Dehydration synthesis: chemical
reaction that joins monomers to
make polymers; also creates a H2O
How do they connect?
- 2H’s and 1 O have to be removed to
link reactants. These atoms form 1
water molecule
Dehydration Synthesis:
- Underline the atoms that become the
H2O
+
+ H2O
How do we break them apart?
- Hydrolysis: chemical reaction that
takes in a H2O to break polymers
into monomers
Hydrolysis:
- Underline the atoms that WERE the
H2O
H2O
+
CARBOHYDRATES
What do they do?
1.Monosaccharides – instant energy
2.Polysaccharides – short term energy
storage (Starch vs. glycogen)
3.Structure of the cell – Plant cell wall
CARBOHYDRATES
(CHO)
Examples:
1.Starch (amylose)
2. Sugar (Glucose, lactose, fructose…)
3. Fiber (cellulose)
What do they have
in common?
Lipids
Made of: 1 glycerol + 3 Fatty Acids 
1 Fat molecule
Lipids
Fat molecule is called a Triglyceride
Lipids
NO TRUE MONOMER.
DOESN’T FORM A CHAIN
Lipids – NO MONOMER!
Once we connect the three fatty acids to
the glycerol, we can not connect anything
else.
No endless chains like with carbs, proteins
and nucleic acids.
Lipids
How do the 4 parts combine?
Any guesses???
Lipids
But we need THREE reactions to make 1
triglyceride
Lipids
 Include: fats, oils, waxes;
steroids
Lipids
Function:
1. long term energy storage
2. Cell Structure: membrane
3. Cushioning
4. Insulation
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
Amino acids form a chain called
polypeptides.
- using same dehydration synthesis
reaction
+
2 unlinked amino acids
1 polypeptide
+ H2O (not shown)
Polypeptides twist and fold into a 3D
shape to make a protein
- only folded proteins are functional
Function:
Proteins
Example:
1.Structure
- cartilage
2.Messengers
- Hormones
3.Speed up chem.
Reactions
- Enzymes
4.Fight disease
- Antibodies
Structure of Nucleic Acids
Nucleotides: monomer of nucleic
acids
Three Parts of a nucleotide:
 5 carbon Sugar – C, H, O
 Phosphate group - PO3
 Base – N, C, H
Structure of Nucleic Acids
P
Base
o
CH2
H
H
H
H
OH
H
P = Phosphate = H2PO3
Structure of Nucleic Acids
So what elements are involved:
Sugar?
PHOSPHate?
NITROGENous base?
Nucleic Acids
General Role:
“information
molecules”; tell our
body how to
make/do what it
needs to
Examples of Nucleic Acids
DNA:
Full name: deoxyribonucleic acid;
Sugar: deoxyribose
Possible bases: A, T, G, C
Number of chains: two twisted together
Function: “cookbook”, the master copy of
information
Examples of Nucleic Acids
RNA:
Full name: ribonucleic acid;
Sugar: ribose
Possible bases: A, U, G, C
Number of chains: one spiral chain
Function: single recipe, temporary copy of
the instructions for 1 protein
Nucleic Acids ANALOGY
DNA = cookbook, ALL the recipes
RNA = index card copy of 1 recipe
Protein = tasty food that is made from the
recipe