Download THE MOLECULES OF LIFE

THE MOLECULES OF LIFE
CH 5
I. Carbon and the Molecules of
Life
Properties of Carbon:
 Carbon can form 4 covalent
bonds. Why?
 Bonds can be single or double
bonds
 Carbon easily bonds with
other elements like S H O P N
 Carbon can form rings,
chains or branches
 Result: HUGE variety of
carbon based molecules of life
II. The 4 Molecules of Life
Carbohydrates
Lipids
Proteins
Nucleic acids
A. Monomers and Polymers
 Polymer: molecule made of
many repeating units linked
together
 Monomer: a single unit
B. Building and Breaking down
polymers
1. Making polymers
 Dehydration reaction:
link monomers together
with the removal of
water. Uses energy
2. Breaking polymers
 Hydrolysis reaction:
break down polymer to
monomers with the
addition of water.
Releases energy
http://resource.rockyview.ab.ca/t4t/bio
20/mm/m7/hydrolysis/Bio20_Hydrolys
is_Final.swf
C. Carbohydrates
 Molecules that are made
of sugar
 3 types:
Monosaccharides
Disaccharides
Polysaccharides
1. Monosaccharide
 Structure: single sugar
molecules
 Function:
 Isomers: molecules with
same chemical formula but
different arrangement of
atoms
2. Disaccharides
 Structure: 2
monosaccharides linked by
dehydration reactions
http://www2.nl.edu/jste/biochem.htm
 Function:
3. Polysaccharides
 Structure: many GLUCOSE
molecules linked by
dehydration reactions
 3 groups: starch glycogen
cellulose
 Function:
i. Starch: store glucose in
plants for later use
ii. Glycogen: store glucose in
animals for later use
iii. Cellulose: makes up cell
wall in plants
4. Interconversion of starch and
glycogen
http://bcs.whfreeman.com/thelifewire/content/chp03/0302002.html
D. Lipids
 Molecules that are all
hydrophobic
 3 groups
Triglycerides
Phospholipids
Waxes and steroids
1. Triglycerides
 Structure: 1 glycerol + 3
fatty acids linked by
http://www2.nl.edu/jste/biochem.htm
 Fatty acid: long chain of
carbon and hydrogen
Saturated fatty acid: no
carbon-to carbon double
bond
Unsaturated fatty acid: at
least one carbon-to-carbon
double bond
 Function: long term energy
storage and insulation and
buoyancy
 Triglycerides are completely
hydrophobic
http://bcs.whfreeman.com/thelifewire/content/chp03/0302002.html
2. Phospholipids
 Structure: 1 glycerol + 2 fatty
acids + 1 phosphate head
 Phospholipids are
amphipathic: polar head and
nonpolar tail
 Function: form phospholipid
bilayer in cell membranes
http://www.uic.edu/classes/bios/bios100/l
ectures/membranes01.htm
http://www.wisconline.com/objects/ViewObject.aspx?I
D=AP1101
3. Waxes and steroids
 Waxes: protection and
prevent water loss
 Steroids: chemical messengers
in a body
E. Proteins
1. Structure: long chains of amino
acids linked by
http://www2.nl.edu/jste/biochem.htm
2. Amino acids: there are 20
different amino acids each with
different R group
There are 100,000 different
proteins yet only 20 different amino
acids. How?
http://bcs.whfreeman.com/thelifewire/content/chp03/0302002.html
3. Protein folding
 As a protein is made, it folds
into a particular shape.
o The shape of a protein is
important in the job it does
o The way a protein folds
is determined by
o
Different proteins
perform different jobs
because
 Proteins can also unfold by
denaturation due to changes in
temp and pH
 When a protein unfolds
4. Function of Proteins
 Transport molecules
 Defense
 Structure/support/movement
 Enzymes
5. Enzymes
 Protein catalysts that speed
up a chemical reaction
 Lower the activation energy
needed to start a reaction
 Each enzyme only catalyzes
one reaction
 How enzymes work:
o Substrate binds to
enzyme’s active site like
lock and key
o In active site, substrate
is converted to product
o Product leaves active
site and enzyme is free to
work on another reaction
http://www.stolaf.edu/people/giannini/fla
shanimat/enzymes/enzyme.swf
http://highered.mcgrawhill.com/sites/0072943696/student_view0/
chapter2/animation__how_enzymes_wor
k.html
 Enzyme reactions are affected
by temperature and pH
o All enzymes have an
optimal temperature and pH
where they produce the most
amount of product
EX:
o
Above the optimal temp
the enzyme
o Below the optimal temp the
enzyme and substrate are
moving more slowly so they
react less
F. Nucleic Acids
1. structure: many
nucleotides linked by
2. nucleotides: a 5 carbon
sugar, a phosphate, 1 of 4
bases
3. Function:
DNA: stores hereditary
information
RNA: expresses hereditary
information