Download 6.3 Life Substances

6.3 Life Substances
Molecules of Life
Role of Carbon in Organisms


Carbon has four electrons in outer energy level
Four covalent bonds fill energy level
Role of Carbon in Organisms



Carbon can bond with other carbon atoms
Double bond = each atom shares two electrons
Triple bond = each atom shares three electrons
Role of Carbon in Organisms


When carbon atoms bond together they can
form chains, branched chains or rings
This makes a huge number of carbon
structures possible
Role of Carbon in Organisms

Compounds with the
same simple structure
can have different
forms called isomers
Role of Carbon in Organisms




Carbon compounds can have thousands of
carbons
Polymer = a large molecule formed when
many smaller molecules bond together
Condensation = large molecule is formed by
removing H-O-H
Hydrolysis = large molecule is broken apart
by adding H-O-H
Role of Carbon in Organisms
Carbohydrates





Used by cells to store and release energy
Organic compound
with carbon, hydrogen2, and oxygen
Simple carbohydrate = monosaccharide
Two sugar carbohydrate = disaccharide
Many sugars = polysaccharide
Carbohydrates
Molecules of Life




Carbohydrates
Lipids
Proteins
Nucleic Acids
Lipids


Used by cells to store energy, insulate and in
protective coatings
Organic compound with many more carbon
and hydrogen than carbohydrates


For example, beef fat C57H110O6
Not soluble in water because
lipids are non-polar
Lipids

2 main types

Each made of 3 fatty acids and a glycerol
Saturated—bad for you (butter)
Unsaturated—good for you (peanut butter)


Lipids
Proteins


Provide structure and carry out cell metabolism
Large polymer built of amino acids


Carbon, hydrogen, oxygen, nitrogen, sulfur
There are 20 common
amino acids that can
build thousands of proteins
Proteins


Amino acids link
together in
peptide bonds
Number and order
of amino acids
determines the
kind of protein
Proteins





Contract muscle tissue
Transport oxygen in bloodstream
Provide immunity
Carry out chemical reactions
Enzyme = protein that changes the rate of a
chemical reaction
Nucleic Acids




Stores cellular information in code
Made up of nucleotides
Carbon, hydrogen, oxygen, nitrogen
phosphorus
Arranged in a base, a sugar, and a
phosphate group
Nucleic Acids




DNA = Deoxyribonucleic acid
Contains instructions on how to make
enzymes and proteins
Genetic code for how an organism looks
Passed from one generation to the next
Nucleic Acids - DNA
Nucleic Acids


RNA = ribonucleic acid
Makes copies of DNA
for use in making
proteins