Download Biochemistry1

The Chemistry of Life
What are living
creatures made of?
Why do we have
to eat?
Regents Biology
2006-2007
Elements of Life
 96% of living
organisms is
made of:




carbon (C)
oxygen (O)
hydrogen (H)
nitrogen (N)
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WHAT IS AN ELEMENT??
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Elements and Atoms
 An element is a pure substance made
up of only one type of atom
 An atom is the smallest particle of an
element that still has all of the
properties of that element
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Levels of Organization
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What are atoms made up of?
 Subatomic particles
Proton –Positively
charged particle found in
the nucleus
 Neutron – Neutrally
charged particle found in
the nucleus
 Electron – Negatively
charged particle orbiting
the nucleus

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http://www.youtube.com/watch?v=lP57gE
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Atoms, Molecules, Compounds
 Atoms with the same number of
neutrons, protons, and electrons make
up an element
 Two or more atoms together is called a
molecule
 When the atoms of a molecule are
different elements it is called a
compound

Compound – combination of two or more
elements
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How many can you count?
 Atom:
 Element:
 Molecule:
 Compound:
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Element – pure
substance made of
only one type of atom
Atom
Subatomic
Particles
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NOT ALL ATOMS ARE EQUAL
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Isotope
 Atoms of the same element have a
different number of neutrons
Changes mass (makes it heavier)
 Charge remains the same
 Chemical properties remain the same

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 Some isotopes nuclei are unstable and
breakdown easily – radioactive isotopes
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Uses of Radioactivity
 Carbon dating

Figuring out the time of decay for isotopes helps to
date fossils and rocks
 Radiation as cancer treatment, kills bacteria in

food
Used as tracers to follow movements of
substances in organisms
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Compound
Molecule
Element
Atom
Subatomic
Particles
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HOW ARE MOLECULES AND
COMPOUNDS CREATED?
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 Atoms can hold a maximum number of
electrons in their outer shells
 Having the maximum number satisfies
an element and it becomes stable
 Atoms are always looking to share,
lose, or obtain more electrons
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Ways to get connected!
 Four types of bonds
Ionic bonds
 Covalent bonds
 Van der Waals forces
 Hydrogen bonds

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Ionic bonds
 An ION is an atom that has a positive
or a negative charge
 Occurs when an electron is
transferred from one atom to another
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Ionic Bonds
 The atom that loses an electron
becomes positively charged! (+)
 The atom that gains an electron
negatively charged! (–)
 (+) attracts (-) like sides of a magnet!
http://www.youtube.com/watch?v=xTx_D
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Covalent bonds
 “Co” = with
Coworker
 Cooperate
 When two atoms share an electron – single bond
 Share two electrons = double bond
 Three electrons = triple bond

http://www.youtube.com/watch?v=UR4eG60
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Covalent Bonds
 Atoms have different abilities to attract




electrons in a covalent bond
The sharing may not always be equal
When sharing is equal the molecule is
nonpolar
When sharing is unequal the molecule is
polar
Water is an example of a polar molecule
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Hydrogen bonds
 When partially

negative and
partially positive
regions of a
molecule attract
the opposite
charge in another
molecules
INTERmolecular
bond!
Between different
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Biology
Van der waals forces
 Occur when sections of oppositely

charged regions of atoms come close
enough together to attract one another
These forces allow geckos to climb walls
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Practice makes perfect
 On a separate sheet of paper:

Which are elements? Compounds? How do you
know?
H2
CO2
NaCl
Fe2
If a scientist were to study the protons of an
atom where would they look?
 What is the difference between a covalent and
ionic bond?
 If an atom loses an electron does it have a
negative or a positive charge? How do you
know?
 How do hydrogen bonds form?

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MOLECULES OF LIFE
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Do Now

Which are elements? Compounds? How
do you know?
H2

CO2
NaCl
Fe2
If a scientist were to study the protons of
an atom where would they look?
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Review
 Electrons help atoms bond to one other
 Two or more atoms of different


elements bonded together is called a
compound
There are two types of compounds in
life: organic and inorganic
What do you think the difference may
be between organic compounds and
inorganic compounds?
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WHAT DO YOU THINK THE
DIFFERENCE MAY BE
BETWEEN ORGANIC
COMPOUNDS AND
INORGANIC COMPOUNDS?
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HAVE CARBON AND HYDROGEN!!!
ORGANIC COMPOUNDS
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Molecules of Life
 Put C, H, O, N together in different
ways to build living organisms
 What are bodies made of?

4 Types of macromolecules
 carbohydrates
 sugars & starches
 proteins
 fats (lipids)
 nucleic acids
 DNA, RNA
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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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A large molecule – has many, many atoms!
MACROMOLECULE
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TYPES OF MACROMOLECULES
ORGANIC
1. Organic compounds –
always contain carbon
and hydrogen!
1.
INORGANIC
 2. Inorganic compounds usually lack carbon
- when carbon is present
it is usually combined
with oxygen
Examples:
exs. H2O, NaCl, CO2
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Organic Molecules
 Other common elements found in
organic molecules
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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 HAPPENS TO FOOD
AFTER YOU EAT IT??
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 Ingest – eat it!
 Digest – break it into smaller
units
 Absorb – into the blood
 Distribute – to all the cells in
your body
 Assimilate – turn in to
something else!
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How do we make these
molecules?
We build them!
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2006-2007
Building large molecules of life
 Chain together smaller molecules

building block molecules = monomers
 Big molecules built from little molecules

polymers
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Prefixes
 Mono = ________
 Poly = _________
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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
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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Organic Molecules and Digestive End
Products
Organic Molecule Digestive End Product(s)
carbohydrates
Simple sugars
(monosaccharides)
Proteins
Amino acids
lipids (fats)
3 fatty acids and glycerol
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How to build large molecules
 Synthesis
building bigger
molecules from smaller
molecules
 building cells & bodies

 repair
 growth
 reproduction
+
ATP
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WHAT DOES IT MEAN TO BE
DEHYDRATED?
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Dehydration Synthesis,
Condensation synthesis
 Removing water to join monomers into
polymers
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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
taking big molecules apart
 getting raw materials

 for synthesis & growth

making energy (ATP)
 for synthesis, growth & everyday functions
+
ATP
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Hydrolysis
 To lyse, or break, using water
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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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