Transcript The Chemistry of Life - Wasco Union High School

The Chemistry of Life
What are living
creatures made of?
Why do we have
to eat?
Regents Biology
2006-2007
Chapter 6
Chemistry in Biology
6.1 Atoms, Elements, and Compounds
1. Atoms
 Chemistry is the study of matter.
A. Atoms are the building blocks of matter.
 Neutrons and protons are located at the
center of the atom.
1. Protons are positively charged
particles.
2. Neutrons are particles that have no
charge.
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Chemistry in Biology
Chapter 6
6.1 Atoms, Elements, and Compounds
3. Electrons are negatively charged
particles that are located outside the
nucleus.
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Chemistry in Biology
6.1 Atoms, Elements, and Compounds
2. Elements
 An element is a pure substance that cannot
be broken down into other substances by
physical or chemical means.
 There are over 100 known elements, 92 of
which occur naturally.
 Each element has a unique name and
symbol.
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Chemistry in Biology
6.1 Atoms, Elements, and Compounds
The Periodic Table of Elements
 Horizontal rows are called periods.
 Vertical columns are called groups.
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3. Elements of Life
 96% of living
organisms is
made of:




carbon (C)
oxygen (O)
hydrogen (H)
nitrogen (N)
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What is a Molecule
Covalent bonds hold 2 or more atoms
together to form a molecule.
A. Important Molecules
 H2O
Water
 O2
Oxygen
 CO2
Carbon Dioxide
 C6H12O6
Glucose
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Why do elements form molecules.
1. To fill their outer shell with electrons.
2. This is called bonding.
3. Two types of bonding
a. covalent = Sharing
b. ionic = Transferring
4. Molecules are formed by covalent
bonding.
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4. Macro-molecules of Life
A. Put C, H, O, N together in different
ways to build living organisms
B. What are bodies made of?
1. carbohydrates
 sugars & starches
2. proteins
3. fats (lipids)
4. nucleic acids
 DNA, RNA
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How do we make these molecules?
We build them!
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2006-2007
Why do we eat?
 We eat to take in more of these chemicals

Food for building materials
 to make more of us (cells)
 for growth
 for repair

Food to make energy
 calories
 to make ATP
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ATP
What do we need to eat?
 Foods to give you more building blocks
& more energy
 for building & running bodies
carbohydrates
 proteins
 fats
 nucleic acids
 vitamins
 minerals, salts
 water

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 What do all
macromolecules
have in common?
C. They all contain Carbon
1.
2.
3.
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Has 4 valence electrons
Forms many types of
covalent bonds.
Forms the backbone of
all macromolecules
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What do all
macromolecules
have in common?
What is a polymer?
What is a
monomer?
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2. They are all polymers

A polymer is a long
molecule consisting of
many similar building
blocks called
monomers
3. They are all assembled by
a Dehydration reaction
(Condensation).
How are polymers
assembled?
HO
1
Dehydration Reaction
(Condensation) Water Making
3
2
H
Unlinked monomer
Short polymer
Dehydration removes a water
molecule, forming a new bond
HO
Figure5.2A
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1
2
H
HO
3
H2O
4
H
Longer polymer
(a) Dehydration reaction in the synthesis of a polymer
How are
polymers taken
apart?
 Polymers are disassembled
by

HO
Hydrolysis (water Breaking)
1
2
3
4
Hydrolysis adds a water
molecule, breaking a bond
HO
Figure 5.2B
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1
2
3
(b) Hydrolysis of a polymer
H
H2O
H
HO
H
Building large molecules of life
 Chain together smaller molecules

building block molecules = monomers
 Big molecules built from little molecules

polymers
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Building large organic molecules
 Small molecules = building blocks (Monomers)
 Bond them together = polymers
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Building important polymers
Carbohydrates = built from sugars(saccharides)
sugar – sugar – sugar – sugar – sugar – sugar
Proteins = built from amino acids
amino amino amino amino amino amino
acid – acid – acid – acid – acid – acid
Nucleic acids (DNA) = built from nucleotides
nucleotide – nucleotide – nucleotide – nucleotide
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How to build large molecules
 Synthesis (Dehydration)
building bigger
molecules from smaller
molecules
 building cells & bodies

 repair
 growth
 reproduction
+
ATP
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Example of synthesis
amino acids
protein
 Proteins are synthesized by bonding amino acids
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amino acids = building block
protein = polymer
How to take large molecules apart
 Digestion (Hydrolysis)
taking big molecules apart
 getting raw materials

 for synthesis & growth

making energy (ATP)
 for synthesis, growth & everyday functions
+
ATP
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Example of digestion
ATP
ATP
ATP
ATP
ATP
starch
ATP
glucose
ATP
 Starch is digested to glucose
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Any
Questions?
Penguins
gone bad!
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Old Food Pyramid
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New Food Pyramid
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Don’t forget water
 Water
65% of your body is H2O
 water is inorganic

 doesn’t contain carbon
 Rest of you is made of carbon molecules

organic molecules
 carbohydrates
 proteins
 fats
 nucleic acids
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