Download Ch. 4: From Chemistry to Energy to Life

Chapter 4: From Chemistry to
Energy to Life
www.aw-bc.com/Withgott
Chemistry and the Environment




conservation of matter
atoms
protons (+)
neutrons
electrons (-)
Isotopes have a different number of neutrons in the atom
– some are radioactive
– half-life of minutes to millions of years
Ion is an atom that gains an electron (-) or loses one (+)
–
Ca+2 calcium which has lost 2 electrons
Compounds


Organic
have carbon (C), oxygen (O), hydrogen
(H) and nitrogen (N) in them as the core
example: CO2 carbon dioxide
Inorganic
any other compound
example: NaCl table salt
Solutions

mixture of substances
–
–
–
air is a solution of gases
tap water is a solution of liquids
human blood
pH




0 - 14
0-7 acid
7 is neutral
7-14 base
www.aw-bc.com/Withgottt
Macromolecules



building blocks of life
large in size compared to other simple
molecules like water and sugar
proteins, carbohydrates, lipids, nucleic acids
Synthetic Polymers






plastics
man-made
not present in nature
derived from hydrocarbons
resist chemical breakdown
can create problems in wildlife
Compartmentalization of
Macromolecules



natural macromolecules make up cells, the
unit of life, from the simple bacteria to more
complex organisms like you and I.
Prokaryotes
Eukaryotes
Energy



potential energy: energy present in a
molecule
kinetic energy: energy produced by the
movement of a molecule
chemical energy: energy held in the bonds of
a molecule
Thermodynamics: Energy
conservation

First Law: energy is not created nor
destroyed, its only transformed.
–

energy in food
Second Law: nature of energy will change
from more ordered one to a more chaotic
one.
–
decomposition of a dead organism
Light Energy Produces Food

autotrophs: produce their own food with the
use of solar energy known as
photosynthesis. Example→plants which
become the primary producers
6CO2 + 6H2O → C6H12O6 +  6O2
carbon water glucose oxygen
dioxide

Cellular Respiration Releases
Chemical Energy

heterotrophs: consume autotrophs to obtain
energy. example→animals which become the
primary consumers

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
www.aw-bc.com/Withgott
Chemosysthesis



chemical-bond energy of hydrogen sulfide
(H2S) to transform inorganic carbon into
organic compounds.
Present in bacteria found in the hydrothermal
vents at the bottom of the ocean
6CO2 + 6H2O → C6H12O6 + 3H2SO4
Origin of Life



Primordial soup: simple inorganic
compounds under special conditions formed
the first organic compounds.
Panspermia hypothesis: microbes from outer
space came to contact with earth and
evolved.
Chemoautotrophic theory: proposed the
bacteria from the hydrothermal vents came
first.
Evolution through the Fossil records


comparison of genes
Prokaryotes
–
–

history of life bacteria
Archaea
Eukaryotes
protists
– plants
– fungi
– animals
THE END
–
www.aw-bc.com/Withgott