1. 2 figure 4.1 3 4 carbon has four valence electrons and may form single, double, triple, or...
TRANSCRIPT
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2Figure 4.1
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Carbon has four valence electrons and may form single, double, triple, or quadruple bonds
Carbon compounds range from simple molecules to complex ones
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(a) Methane
(b) Ethane
(c) Ethene (ethylene)
Molecular Formula
Structural Formula
Ball-and-Stick Model
Space-Filling Model
H
H
H
H
H
H
H
H
H
H
H H
HH
C
C C
C C
CH4
C2H
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C2H4
Name and Comments
Figure 4.3 A-C
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H O N C
Hydrogen
(valence = 1)
Oxygen
(valence = 2)
Nitrogen
(valence = 3)
Carbon
(valence = 4)
Figure 4.4
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H
HH
H
H
H H H
H
H
H
H H H
H H H
H H
H
H
H
H
H
H
H
H
H
H H H H
H H
H H
H H H H
H H
H H
HH
HH
H
H
H
C C C C C
C C C C C C C
CCCCCCCC
C
C
C
C
C
C
C
CC
C
C
C
H
H
H
HH
H
H
(a) Length
(b) Branching
(c) Double bonds
(d) Rings
Ethane Propane
Butane isobutane
1-Butene 2-Butene
Cyclohexane Benzene
H H H HH
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(a) A fat molecule (b) Mammalian adipose cells100 µm
Fat droplets (stained red)
Figure 4.6 A, B
C4H10
The molecular formula does not necessarily tell you the structural formula…explain.
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• Molecules with the same molecular formula, but there atoms are connected differently (Different connectivity) • Resulting in different structural formula. • Structure = function, therefore structural isomers function or behave differently
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AIM: How does carbon lead to the diversity of life?
Chapter 4 – Carbon and the Molecular Diversity of Life
• Differ in their spatial arrangement about a double bonded carbon
Cis Trans
Cis-2-butene
Trans-2-butene
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This can happen only when there is an asymmetric carbon = a carbon with four DIFFERENT groups attached to it.
Asymmetric carbon
mirror
Thalidomide, an extreme example of isomers behaving differently
The birth defects caused by thalidomide, which was inadvertently taken with R-thalidomide to treat morning sickness symptoms
ConclusionJust because two molecules have the same molecular formula and may even have the same connectivity, if they can’t be overlaid on top of each other, they aren’t the same.
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L-Dopa
(effective against Parkinson’s disease)
D-Dopa
(biologically inactive)Figure 4.8
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CH3
OH
HO
O
CH3
CH3
OH
Estradiol
Testosterone
Female lion
Male lionFigure 4.9
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•There are six functional groups that concern us in biology:
•Hydroxyl group (-OH)
•Carbonyl group (>C=O)
•Carboxyl group (-COOH)
•Amino group (-NH2)
•Sulfhydryl group (-SH)
•Phosphate group (-OPO32-)
•These functional groups are hydrophilic and increase the solubility of organic compounds in water.
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•Structure – a hydrogen atom bonded to an oxygen atom which is then bonded to the carbon skeleton of the organic molecule (-OH). (This is not the same thing as an hydroxide ion (OH-)).
•Name of Compounds – alcohols (names usually end in –ol).
•Example – ethanol – the alcohol found in beer and wine.
•Properties:
•Polar as a result of the electronegative oxygen drawing electrons toward itself.
•Attracts water molecules
•Helps dissolve organic compounds such as sugars.
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1. It is composed of a ribose sugar, three negative phosphates, and an adenine base2. It’s an RNA nucleotide3. Primary energy carrying molecule of the cell – fuel for proteins to do work / accelerate matter
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FUNCTIONALGROUP
STRUCTURE
(may be written HO )
HYDROXYL CARBONYL CARBOXYL
OH
In a hydroxyl group (—OH), a hydrogen atom is bonded to an oxygen atom, which in turn is bonded to the carbon skeleton of the organic molecule. (Do not confuse this functional group with the hydroxide ion, OH–.)
When an oxygen atom is double-bonded to a carbon atom that is also bonded to a hydroxyl group, the entire assembly of atoms is called a carboxyl group (—COOH).
C
O O
C
OH
Figure 4.10
The carbonyl group ( CO) consists of a carbon atom joined to an oxygen atom by a double bond.
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Acetic acid, which gives
vinegar its sour tatste
NAME OF
COMPOUNDS
Alcohols (their
specific names usually
end in -ol)
Ketones if the carbonyl
group is within a carbon
skeleton
Aldehydes if the carbonyl
group is at the end of the
carbon skeleton
Carboxylic acids, or
organic acids
EXAMPLE
Propanal, an aldehyde
Acetone, the simplest ketone
Ethanol, the
alcohol present in
alcoholic
beverages
H
H
H
H H
C C OH
H
H
H
HH
H
HC C H
C
C C
C C C
O
H OH
O
H
H
H H
H O
H
Figure 4.10
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The amino group (—NH2) consists of a nitrogen atom bonded to two hydrogen atoms and to the carbon skeleton.
AMINO SULFHYDRYL PHOSPHATE
(may be written HS )
The sulfhydryl group consists of a sulfur atom bonded to an atom of hydrogen; resembles a hydroxyl group in shape.
In a phosphate group, a phosphorus atom is bonded to four oxygen atoms; one oxygen is bonded to the carbon skeleton; two oxygens carry negative charges; abbreviated P . The phosphate group (—OPO3
2–) is an ionized form of a phosphoric acid group (—OPO3H2; note the two hydrogens).
NH
H
SH
O P
O
OH
OH
Figure 4.10