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Chapter 2Chapter 2The Nature of LifeThe Nature of Life
Composed of one or more cells Composed of one or more cells Possess inherited information (DNA)Possess inherited information (DNA)ReproduceReproduceDevelop Develop respond to the environment respond to the environment Assimilate and use energyAssimilate and use energyMaintain a relatively constant internal Maintain a relatively constant internal environment (homeostasis)environment (homeostasis)EvolveEvolve
What is life?What is life?
All living things are made of cellsAll living things are made of cells Possess inherited information (DNA)Possess inherited information (DNA)
ReproductionReproduction
Figure 1.3cx Growth and developmentFigure 1.3cx Growth and development
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Living things sense their environmentLiving things sense their environmentFigure 1.3dx Energy utilizationFigure 1.3dx Energy utilization
ORGANIC MOLECULES
OTHER ORGANISMS(CHEMICAL ENERGY)
Heterotrophs- consumers- decomposers
CO2SUNAutotrophs
Carbon sourceEnergy source
Energy flows though Biological Systems
Complexity and organizationComplexity and organization�� HomeostasisHomeostasis
Living things evolveLiving things evolve
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The Chemistry of LifeThe Chemistry of Life
MatterMatter
ElementsElements�� AtomsAtoms
Table 2.1Table 2.1
Figure 2.10 Electron configurations of the first 18 elementsFigure 2.10 Electron configurations of the first 18 elements
Fig. 2.1Fig. 2.1
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MoleculesMolecules
MoleculeMolecule
CompoundCompound
Covalent bondsCovalent bonds�� NonNon--polarpolar�� polarpolar
Chemical BondsChemical Bonds
02.09 Table Salt, an Ionically Bonded MoleculeSlide number: 2
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
17p18n
11p12n
Na Cl+
02.09 Table Salt, an Ionically Bonded MoleculeSlide number: 3
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
17p18n
11p12n
Na Cl+
02.09 Table Salt, an Ionically Bonded MoleculeSlide number: 4
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
17p18n
11p12n
Na Cl+
02.09 Table Salt, an Ionically Bonded MoleculeSlide number: 5
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
17p18n
11p12n
Na Cl+
5
02.09 Table Salt, an Ionically Bonded MoleculeSlide number: 6
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
17p18n
11p12n
Na Cl+
(+) (–)
02.09 Table Salt, an Ionically Bonded MoleculeSlide number: 7
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
NaCl
11p12n
(+)
17p18n
(–)
Hydrogen BondsHydrogen BondsFigure 3.9 The pH of some aqueous solutionsFigure 3.9 The pH of some aqueous solutions
Water will dissociate Water will dissociate into ionsinto ions
Acids Acids –– more Hmore H++
than OHthan OH--
Bases Bases –– more OHmore OH--
than Hthan H++
Neutral HNeutral H++ = OH= OH--
pH can play a significant role in pH can play a significant role in plant growthplant growth
ENERGYENERGY
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Kinetic energy is Kinetic energy is energy that is actually energy that is actually doing workdoing work
Potential energy is Potential energy is stored energystored energy
Potential andPotential and
kinetic energykinetic energy
First law ofFirst law of ThermodynamicsThermodynamics
1) Energy cannot be created or destroyed, 1) Energy cannot be created or destroyed, only changed in form.only changed in form.
Heat
(out)
Chemical energy
(IN)
Sound
(out)
Kinetic(out)
Second Law of ThermodynamicsSecond Law of Thermodynamics
When energy is transformed, the When energy is transformed, the amount of useful energy decreases amount of useful energy decreases (heat is the most useless form of (heat is the most useless form of energy)energy)
****(Quality changes not quantity)***** ****(Quality changes not quantity)*****
+ 6 O=O
C6H12O6 + 6 O2 6 CO2 and 6 H 20 + energy
O=C=O
O=C=OO=C=O
O=C=O
O=C=O O=C=O
O=C=O
H-O-HH-O-H
H-O-H
H-O-H
H-O-H
H-O-H
Solarenergy
Wasteheat
Chemicalenergy
(photosynthesis)
Wasteheat
Wasteheat
Wasteheat
Chemicalenergy(food)
Mechanicalenergy(moving,thinking,
living)
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Organic MoleculesOrganic Molecules
Some important termsSome important terms
MacromoleculeMacromolecule-- a large molecule made a large molecule made up of smaller molecules (building blocks or up of smaller molecules (building blocks or subunits)subunits)
PolymerPolymer-- a long molecule consisting of a long molecule consisting of many similar or identical monomersmany similar or identical monomers
MonomerMonomer-- building block (subunit) of a building block (subunit) of a polymerpolymer
PolymerPolymerMonomerMonomerClassClass
polynucleotidepolynucleotideNucleotidesNucleotidesNucleic acidsNucleic acids
polypeptidepolypeptideAmino acidsAmino acidsProteinsProteins
NoneNoneNoneNoneLipidsLipids
polysaccharidepolysaccharideMonosaccharidesMonosaccharides
e.g. glucosee.g. glucoseCarbohydratesCarbohydrates
The synthesis and breakdown of polymersThe synthesis and breakdown of polymers
The structure and classification of some monosaccharidesThe structure and classification of some monosaccharides 03_21 Formation of sucroseSlide number: 4
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
+HO
CH2OH
OH
OH
OH
O
Glucose
HO
CH2OH
OH
HO
O
CH2OH
Fructose
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03_21 Formation of sucroseSlide number: 5
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
+HO
CH2OH
OH
OH
OH
O
Glucose
HO
CH2OH
OH
HO
O
CH2OH
Fructose
03_21 Formation of sucroseSlide number: 7
Copyright © The McGraw-Hill Companies, Inc. Permiss ion required for reproduction or display.
+
H2OHO
CH2OH
OH
OH
OH
O
Glucose
HO
CH2OH
OH
HO
O
CH2OH
Fructose
CH2OHHOOH
CH2OH
OH
O
O
CH2OHO
OH
HO
Sucrose
Storage polysaccharidesStorage polysaccharides The arrangement of cellulose in plant cell wallsThe arrangement of cellulose in plant cell walls
LipidsLipids
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Figure 3.8C
Saturated and unsaturated fatty acids
Examples of saturated and unsaturated fats and fatty acidsExamples of saturated and unsaturated fats and fatty acids
The structure of a phospholipidThe structure of a phospholipid
amino group
H
H
H
N C C
O
OHR
side-chain
carboxyl group
H
H
H
N C C
O
OH
H
H
H
N C C
O
OH
CH2
OH
CH2
C
OH2N
tyrosine
glutamine
Proteins are Proteins are made of amino made of amino acidsacids�� 20 different 20 different
typestypes
ala
leu
ser
glu
glu ala
his gln
ile
ser
tyr
ala
ser
glu
gluFOUR LEVELS OF
STRUCTURE IN
PROTEIN
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
pleated sheet random coil
folded polypeptide chain
two or more polypeptide chains
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Fig.
2.14
b
a
DNAdouble helix
NUCLEOTIDE
nitrogenousbase
O
O
O
O
sugar(deoxyribose)
phosphate group
P
P
P
P
P
P
P
P
P
P
P
P
P
P
CG
T A
G c
A T
G c
T A
AT
O
O
O
O
O
O
O
O
O
O
Genes are segments ofDNA that contain
instructions to makeproteins—the building
blocks of life. The genesin each cell are coded bysequences of nucleotidesIn their DNA molecules.
G T A C
C A T G
Thechromosomes
are filledwith tightly
coiledstrandsof DNA.
Onechromosome
of everypair
is fromeach
parent.
Eachnucleus
contains 46chromosomes,
arrangedin 23pairs.
There is anucleusinsideeach
human cell(except red
blood cells).
Thehumanbody
containsabout 100
trillioncells.