Transcript Chemistry Of The Human Body

Chemistry Of The
Human Body
Structure & Function of
Enzymes
Introduction To Basic
Chemistry
Tortora
Pages 20-25
• Structure of
atoms.
• Atomic number Vs
atomic mass.
• Role of electron
shells
Octet Rule; rule of eight.
Introduction To Basic
Chemistry
Tortora
Pages 20-25
• Covalent bonds
– Sharing electrons
– Outer shell
electrons only
– Rule of eight
Molecule.
• Ionic bonds
– Transfer of outer
shell electrons.
Crystal.
Introduction To Basic
Chemistry
Tortora
Pages 20-25
• NOCH
– Four most common occurring elements in the
human body.
– Why these four?
• All can be in gaseous form.
• All dissolve into water.
• All form easily broken covalent bonds.
• CHNOPS
– Most common 6 elements.
Introduction To Basic
Chemistry
• The most common 13 elements in
the human body. (Exibit 2.1 Pages
21)
• CHOPKINS café (is)
Mg (if you add) Salt.
Tortora
Pages 20-25
Introduction To Basic
Chemistry
• Hydrogen bonds
form between
oxygen (-) and
hydrogen (+)
• Example: Water
Tortora
Pages 20-25
Introduction To Basic
Chemistry
• Chemical reactions
• Dehydration
synthesis
– Making new
molecules by
extracting water.
• Example: Linking
amino acids to make
a protein.
Tortora
Pages 20-25
Introduction To Basic
Chemistry
• Decomposition by
adding water
– Hydrolysis
• Example: Digesting
starch into glucose.
Tortora
Pages 20-25
Introduction To Basic
Chemistry
• Chemical reactions
are either:
• Endergonic: need
more energy than
they release.
or
Tortora
Pages 20-25
Introduction To Basic
Chemistry
Exergonic:
• Release more
energy than they
need.
Tortora
Pages 20-25
The Water Molecule
• Why water is polar.
Tortora
Pages 20-25
The Water Molecule
• Because water
is polar:
– Acts as a
solvent.
Tortora
Pages 20-25
The Water Molecule
• Participates in
chemical reactions.
Tuesday 9/10
Pages 20-25
The Water Molecule
• Water absorbs and
releases heat
slowly.
Tortora
Pages 20-25
The Water Molecule
• Requires a large
amount of heat to
change states.
Tortora
Pages 20-25
The Water Molecule
• Serves as a
lubricant.
Tortora
Pages 20-25
Fig 2-10 Homework Quiz
•
1. T or F Triglycerides are the most common
type of fat in the human body?
•
2. T or F Carbon, oxygen, and nitrogen are the only
three types of atoms found in fats?
•
3. T or F Glycerol forms the three long chains found
in a fat molecule?
•
4. T or F Carbon atom forms the backbone of the fat
molecule?
•
5. T or F Fat molecules are saturated if they contain
all double covalent bonds.
• 6.
T or F
Fat molecules that are unsaturated have
all straight fatty acid chains.
• 7.
T or F
The fatty acid molecules are connected
to a backbone glycerol molecule in a lipid
molecules.
• 8.
T or F Double bonds in fats cause the fatty acids
to bend and so are not straight.
• 9.
T or F Monounsaturated fats have 1 double bond.
• 10. T or F Glycerol has three carbon atoms.
ANSWERS
1. T
2. F
3. F
4. T
5. F
6. F
7. T
8. T
9. T
10. T
Structure of Proteins
• One of four classes of
macromolecules.
• Functions of proteins.
• A polymer composed of
many monomers (amino
acids)
• Peptides are short or
incomplete proteins.
Structure of
Proteins
• Typical amino acid.
–
–
–
–
–
Carbon
Carboxyl group
Hydrogen
Amine group
Radical
• Amino acids are linked by
dehydration synthesis.
• Peptide bond is formed by
water molecule being
extracted.
Structure of Proteins
• Proteins are formed of
polypeptide chains.
• Proteins have four levels
of structure.
• Primary structure is
determined by amino acid
sequence and length.
Structure of Proteins
• Secondary structure
results from near neighbor
interaction.
• Tertiary structure results
from amino acid
interaction with water.
• Quarternary structure
results from polypeptide
interaction.
Structure of Enzymes
• Free energy is
energy within a
cell to do work.
• A reaction that
produces more
free energy
than it uses is
exergonic.
• A reaction the
uses more free
energy is
endergonic.
Activation Energy
• Necessary input
of energy for
reaction to
proceed.
• Catalysis is the
stressing of
chemical bonds
so as to require
less activation
energy.
• Organic
catalysts are
enzymes.
How Enzymes Speed
Up Reactions
• Speed up reactions
by
– Increase the
frequency of
collisions.
– Position substrate
molecules.
Tortora
P. 37
How Enzymes Speed
Up Reactions
• Speed up reactions
by
– Increase the
frequency of
collisions.
– Position substrate
molecules.
Tortora
P. 37
ATP: Energy
Currency
• Metabolism
refers to sum of
all energy use in
the cell or body.
– Energy use is
necessary to maintain
organization.
– Energy is also needed
for growth and
reproduction.
Tortora
Page 33
ATP: Energy
Currency
• ATP acts as
the cell’s
battery.
– Capable of
storing
energy.
– Capable of
releasing
energy.
Tortora
Page 33
ATP: Energy
Currency
Tortora
Page 33
• Structure of the ATP
molecule.
– 1 Adenine molecule + 1
ribose = adenosine.
– 3 phosphates attached
in a string.
– High energy bonds
between the
phosphates.
• Energy is stored as high
energy covalent bonds
between the
phosphates.
Each high energy bond equals 7.3 Kcal/mole.
ATP: Energy
Currency
Tortora
Page 33
• ATP and the release of energy.
• ATP
ADP + Pi + free energy.
• ATP and the storage of energy
• ADP + Pi + Free energy
ATP
ATP: Energy
Currency
• ATP - ADP
Cycle
Tortora
Page 33
SCIENTIFIC METHOD
1. Starts with an observation and/or
question?
2. Develop a hypothesis that’s predicts an
outcome based on known information.
3. Design an experiment that will directly
test the hypothesis.
4. Based on experimental evidence either
support of reject the hypothesis.
Developing a Hypothesis
1. Use the “If”, “Then” format.
2. If (a certain condition exists),
Then (predict the results)
1)
2)
3)
If substrate concentration is increased,
Then reaction rate will increase.
If enzyme concentration is increased,
Then reaction rate will increase.
If temperature is increased,
Then reaction rate will increase.