nucleic acids

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Transcript nucleic acids

THE COMPOUNDS OF LIFE
Review
• Using the example of Kool-Aid and water,
identify the solute and solvent.
• T/F Water is polar. This means it has an
uneven distribution of electrons.
• In water, acids release excess _______ ions.
In water, bases release excess _______ ions.
• BONUS
– Draw a pH scale from zero to 14. Label neutral,
acid, and base.
Spider Silk: Stronger than Steel
• The spider and the web
consists of simple organic
compounds
INTRODUCTION TO ORGANIC COMPOUNDS:
Monomers and Polymers
• Complex chains of organic molecules are made
from small units of organic molecules
• Monomers = one unit
• Polymers = two or more connected units
• Example
– One lego block
– 10 connected lego blocks
• The process is called polymerization
Carbon – the MOST IMPORTANT atom or
organic compounds
• WHY?
– A carbon atom can form four covalent bonds
– Can stably bind with other carbon atoms
– Able to form single, double, or triple bonds
Structural
formula
Methane
Ball-and-stick
model
Space-filling
model
• Carbon skeletons vary in many ways
Ethane
Propane
Carbon skeletons vary in length.
Butane
Isobutane
Skeletons may be unbranched or branched.
1-Butene
2-Butene
Skeletons may have double bonds, which can vary in location.
Cyclohexane
Benzene
Skeletons may be arranged in rings.
Figure 3.1, bottom part
4 MAJOR GROUPS OF MOLECULES
1. CARBOHYDRATES
2. LIPIDS
3. PROTEINS
4. NUCLEIC ACIDS
Carbohydrates
CARBOHYDRATES
• Carbohydrates are sugars
– Basic Name – saccharides
– MONOMER - Monosaccharide
– POLYMER - Polysaccharides are long polymers
of sugars
– Examples
• Bread, candy, sugars
Carbohydrates
• These molecules typically have a formula that is
a multiple of CH2O
• FUNCTION - carbohydrates provide
energy for an organism
Figure 3.4A
• Starch, glycogen, and cellulose are
polysaccharides that store sugar for later use
• Notice what is the monomer for these examples
Starch granules in
potato tuber cells
Glycogen granules
in muscle tissue
Cellulose fibrils in
a plant cell wall
Cellulose
molecules
Figure 3.7
Glucose
monomer
STARCH
GLYCOGEN
CELLULOSE
LIPIDS
Lipids
• These compounds are composed largely of C
and H
– They are non polar.
– It does not mix with water
Figure 3.8A
• FUNCTION - Lipids main function is
energy storage. Lipids also form
biological membranes in cells
• A lipid molecule = one glycerol + three fatty
acids
Fatty acid
Figure 3.8B
• The fatty acids of unsaturated fats (plant oils)
contain double bonds
– They are liquid at room temperature
• Saturated fats (lard) have only single bonds
– They are solid at room temperature
Figure 3.8C
PROTEINS
• Proteins FUNCTION:
– cellular structure
– movement
– defense
– transport
– communication
• Hair is composed of structural proteins
• Enzymes are a type of protein that regulate
chemical reactions
Proteins
• MONOMER – amino acid. There are only 20
amino acids
• POLYMER – protein.
Nucleic Acids
NUCLEIC ACIDS
• Nucleic acids such as DNA and RNA serve as
the blueprints for proteins
• They ultimately control the life of a cell
• Contain C, H, O, N (nitrogen), P (Phosphorous)
MONOMER - nucleotides
– Each nucleotide is composed of a sugar,
phosphate, and nitrogenous base
Nitrogenous
base (A)
Phosphate
group
Figure 3.20A
Sugar
• The sugar and phosphate form the backbone
for the nucleic acid
Nucleotide
Figure 3.20B
Sugar-phosphate
backbone
• FUNCTION – To store
genetic information in
DNA or RNA
– The sequence of the
nucleotides determine
what is made
Base
pair
Nitrogenous
base (A)
Figure 3.20C
Review
• What makes carbon special?
• What are monomers? What are polymers? Can
you give an example for each organic
compound?
• What are the four organic compounds?
• Name a function for each?
Classwork
Work on handout
– Concept map
– Handout on 2-3
• We will go over it
Homework
• SA 2-3 page 48 #1-5
• Finish this chart
Carbo…
Purpose
Monomer
Polymer
Lipid
Protein
Nuc. Acid