Transcript CHAPTER 4

CHAPTER 4
Carbon and the Molecular Diversity of Life
ESLRS:
Core Learning, Critical Thinking,
Communication, Community
STANDARDS:
Chemistry:
1 a,d,e atom structure;
2 a-h bonding;
5 a-d acid/base; more…
Cell Biology:
1 h macromolecules
organic chemistry (o-chem)
• branch of chemistry that specializes in the study of carbon
containing compounds.
• originated in attempts to purify and improve the yield of organic
substances:
– ex. food, medicines, cloth, paper
• 1st based on VITALISM- the belief in a life force outside the
jurisdiction of physical and chemical laws.
• organic compounds seemingly could only arise within living
organisms and inorganic compounds were found in the
nonliving world.
• Cumulative nature of Science… Experiments to disprove
VITALISM and replace it w/ MECHANISM:
– 1) 1800’s Wholler had synthesized Urea from ammonium & cyanate
– 2) Kolbe (his student) made citric acid from inorganic compounds.
UREA
cellular waste product found in
mamalian and amphibian
urine
It was the first organic compound to be artificially synthesized
from inorganic starting materials, thus dispelling the concept of
vitalism. Made from by the reaction of potassium cyanate
with ammonium sulfate.
Figure 4.x1 Urea
Check the valences…
Stanley Miller (1953)
University of Chicago
Helped pioneer the field of
organic chemistry, and replace “Vitalism”
with “Mechanism”.
Was able to synthesize organic
molecules from the inorganic compounds:
H20, NH3, H2, CH4 and high voltage.
(made hydrocarbons & amino acids)
Simulated conditions of primitive Earth to
demonstrate the abiotic synthesis of organic
compounds in a repeatable experiment.
Brought the abiotic synthesis of organic
compounds into the context of evolution,
to support Oparin-Haldane biochemical
evolution. The gasses simulate primitive
Earth’s atmosphere. Shows how the
molecules necessary for life evolved.
•Stanley Miller
Resulted in a paradigm shift
from Vitalism to Mechanism.
Mechanism is the belief that
all natural phenomena,
including the
processes of life are
governed by physical and
chemical laws.
How did Stanley Miller’s
work provide evidence to
support the theory of
Evolution?
Big Idea 1: The process of evolution
drives the diversity and unity of life.
1.D: The origin of living systems is explained by natural
processes.
• 1.D.2: Scientific evidence from many different disciplines
supports models of the origin of life.
• A. Geological evidence provides support for models of the origin of
life on Earth.
– Evidence of student learning is a demonstrated understanding of each of
the following:
– 2.Chemical experiments have shown that it is possible to form complex organic
molecules from inorganic molecules in the absence of life.
• B. Molecular and genetic evidence from extant and extinct
organisms indicates that all organisms on Earth share a common
ancestral origin of life.
– Evidence of student learning is a demonstrated understanding of each of
the following:
– 1.Scientific evidence includes molecular building blocks that are common to all
life forms.
– 2.
Scientific evidence includes a common genetic code.
I.
•
•
Carbon atoms are the most
versatile building blocks of
molecules.
Electron Configuration:
–
–
•
•
WHY CARBON?
4 valence e- = 4 bonds to share
covalently
giving/taking not practical, does
not ionize
Can form chains of differing
length, branching shapes,
rings… and double bonds.
Carbon is used in storage
compounds and cell formation
in all organisms.
The FOUR MAJOR COMPONENTS OF
ORGANIC COMPOUNDS:
Carbon provides the “backbone” or “carbon
skeleton” that other elements are bonded to.
hydrocarbons
Are these molecules polar or nopolar? How do you know?
Hydrocarbons
• Organic molecules
consisting only of
carbon and hydrogen.
• Major components of
petroleum.
• Hydrophobic (repels
water) because bonds
are nonpolar.
• Store a large amount
of energy.
– Ex. Lipids (triglyceride)
in animals.
Big Idea 2: Biological systems utilize
free energy and molecular building
blocks to grow, to reproduce and to
maintain dynamic homeostasis.
• 2.A.3: Organisms must exchange matter with the
environment to grow, reproduce and maintain organization.
• A. Molecules and atoms from the environment are necessary to
build new molecules.
– Evidence of student learning is a demonstrated understanding of each
of the following:
• 1. Carbon moves from the environment to organisms where it
is used to build carbohydrates, proteins, lipids or nucleic acids.
Carbon is used in storage compounds and cell formation in all
organisms.
• 2. Nitrogen moves from the environment to organisms where
it is used in building proteins and nucleic acids. Phosphorus
moves from the environment to organisms where it is used in
nucleic acids and certain lipids.
Isomers
Compounds that have
the same molecular
formula but different
structures…
results in different properties.
3 types-differ:
1)Structural-covalent partners
2)Geometric-double bond
3)Enantiomers-asymmetric C
WHAT TYPE OF ISOMER?
STRUCTURAL ISOMER
Structural isomers differ in covalent arrangements of atoms, and
In the location of double bonds.
GEOMETRIC ISOMER
Geometric isomers differ in spatial arrangements due to the
Inflexibility of double bonds.
ENANTIOMERS
Enantiomers are molecules containing an assymetric carbon,
which are mirror images of each other.
What type of isomer?
ENANTIOMER
Structure
FUNCTION
Ex. Thalidomide
Drug prescribed in the 50’s
And early 60’s to prevent
Morning sickness for thousands
Of women.
One enantiomer caused severe
Birth defects.
II. FUNCTIONAL GROUPS
• Structures involved in reactions and in
defining the molecule’s properties.
• Picture a hydrocarbon… replace a
hydrogen with one of these “clusters” of
atoms.
• Can have different “properties”.
• Most important in chemistry of life:
Hydroxyl, carbonyl, carboxyl, amino,
sulfhydral, and phosphate… All are polar
(hydrophilic).
Figure 4.8 A comparison of functional groups of female (estradiol) and male
(testosterone) sex hormones
Figure 4.8x1 Estrone and testosterone
Figure 4.8x2 Male and female mallards
Figure 4.8x3 Male and female peacocks
FUNCTIONAL GROUPS
• HYDROXYL (alcohol)
• names end in “ol” (C-OH HO-C)
– polar
– molecules can dissolve in water
• CARBONYL carbon double bonded to oxygen…
– 1. Aldehyde - terminal carbon bond H-C=O
– 2. Ketone - inner carbon bond -C=O
– polar
FUNCTIONAL GROUPS
• SULFHYDRYL = sulfur and hydrogen
–
–
–
–
stabilize protein structure
disulfide bridges
-SH
ex. # & position in hair proteins determine if curly or straight
polar
• PHOSPHATE = OPO3 2– transfer of energy between organic
– molecules
– polar
FUNCTIONAL GROUPS
• AMINO nitrogen & 2
hydrogen, called “amine”
– tends to pick up protons in
solution,
– making it a base
– -NH2 +H+ --> -NH3+
– Polar
• CARBOXYL (-COOH)
organic acids HO-C=O
– tends to dissociate in
water, gives H+ (makes it
an acid)
– Polar
– Hint: Carbonyl + Hydroxyl
= Carboxyl 
FUNCTIONAL GROUPS
• METHYL 1 CARBON bonded to 3 HYDROGENS
– Addition of a METHYL GROUP to DNA, or to molecules
bound to DNA, effects the expression of genes.
– Epigenetics means “Beyond the Genome” and studies how
an organism’s environment
– Effects methlyation of the
– DNA
Big Idea 4: Biological systems interact,
and these systems and their
interactions possess complex
properties.
• At the molecular level, the subcomponents of a biological
polymer determine the properties of that polymer.
• 4.A: Interactions within biological systems lead to complex
properties.
4.A.1: The subcomponents of biological molecules and their
sequence determine the properties of that molecule.
•
• a. Structure and function of polymers are derived from
the way their monomers are assembled.