Common Organic Compounds:
•Hydrocarbons (Fats and Oils)
-cell membranes
-energy storage
Chapter 4
Introduction to fundamentals of life,
organisms, and taxonomy
•Carbohydrates (Sugars,
Starches Cellulose,)
-energy source
• Proteins (Muscles & Enzymes)
-cell structure, function
-catalyze reactions (tools)
Living things! Hooray
• Nucleic acids (building blocks
of DNA and RNA)
-genetic info
-protein synthesis
Photosynthesis
• The synthesis of organic compounds (sugars) from
simple inorganic compounds (CO2 and H2O) in the
presence of chlorophyll using light energy from
the sun.
– General Formula for PS
– The Organs of Photosynthesis - Leaves and
Chloroplasts
– Chloroplast Structure and Photosynthesis
– Photosynthetic Pigments and the
Electromagnetic Energy Spectrum
Chloroplast
6CO2 + 6H2O +
= C6H12O6 + 6O2
1
6H2O + 6CO2 + Solar energy
chlorophyll
C6H12O6 (sugar) + 6O2
Chemical Energy to Work
Photosynthesis:
• Most organisms ultimately
depend on sunlight to
capture energy
• Can you think of exceptions?
Chemosynthesis:
• Hydrothermal vents (hot)
•H2S
• Methane seeps (cold)
•CH4
Note* energy is captured by
photosynthesis/chemosynthesis
AND released by respiration!
The missing terms are:
6H2O + 6CO2 + Solar energy = C6H12O6 + 6O2
A.
B.
C.
D.
C6O2 ; C6H12O6
6O2 ; C6H6O12
C6O2 ; C12H6O12
6CO2 ; C6H12O6
Surface Area to Volume Ratios
Why are cells so small?
i.e. What are the
determinants of cell
size?
1- Surface area to
volume ratio
Don’t Say
I didn’t warn
you!
2- Diffusion rates
2
Diffusion and Osmosis
• Hypotonic
• Isotonic
• Hypertonic
A fresh water fish would:
A.
B.
C.
D.
Gain water and excrete a lot.
Loose water and drink a lot.
Gain water and excrete little.
Loose water and drink little.
Taxonomy and Systematics:
a broader classification system that
also shows evolutionary relationships
• A hierarchical system:
species
Genus Family
Class
Order
Kingdom
Phylum
• 2 Kingdom system: K. Plantae = autotrophs and K. Animalia = heterotrophs
• 5 Kingdom system: Monera, Fungi, Protista, Animalia,
Plantae
• 3 Domain System:
Old 5 Kingdom Classification
3 Domain
Taxonomy of life
3
The connection between classification and phylogeny
What are species?
• Biological Species Concept
– Group of reproducing individuals
• Morphological S. C.
– Groups of “same” looking things
• Phylogenetic S. C.
– Group of individuals distinct in their ancestry
and descent
• Other S. C…
Adaptation
• Adaptation - Process where species acquire traits
that allow them to survive in their environments.
– Limited range of physiological modifications.
– Inheritance of specific genetic traits allowing a species
to live in a particular environment.
• Population-level phenomenon.
– Evolution
What is evolution?
• People have understood that things evolve
for 1000’s of years…but how does it
happen?
Canines- Canis familiaris
"Yo quiero
Artificial
Selection”
4
Natural Selection puts
forward two main ideas:
• The concept of evolution, meaning that
the diversity of species on the earth
today arose by decent and modification
of existing species
• That natural selection is the cause of
adaptive evolution, i.e., that the
modification of existing species results
from the interaction between an
individual’s genetic makeup and the
environment leading to differential rates
of survival and reproduction.
• Darwin’s main observations and
conclusions…
Darwin’
Darwin’s main points as published 1859 in: The
Origin of Species by Means of Natural Selection:
• Organisms arise by descent and modification
of existing species
• Natural selection acts on individuals but results in changes in
the population
• All organisms living today are the consequences of the
environmental conditions faced by their ancestors
• Organisms appear well adapted to current conditions because
these resemble the conditions in which they evolved.
• The theory does not predict perfect adaptation,
adaptation, it is not
purposeful; rather, using random variation as the raw material,
organisms evolve to match their environment by being the best
available,
available, not the best imaginable.
Darwin’s Natural Selection
• Observation 1- Overproduction
– Most populations have the potential to produce many
more offspring than the environment can support with
food, space, resources
– Therefore: There is a struggle for existence among
individuals, only a fraction survive.
• Observation 2- Individual Variation
– Individuals vary in their characteristics, much of this
variation is heritable,
– Therefore: there is differential reproduction success
between individuals. Those best suited leave a larger
share of offspring.
What was Chuck’s major contribution?
A. Populations can grow faster than their
resources can support.
B. There is a struggle for existence within
populations
C. Variation occurs within populations and is
often heritable.
D. Organisms show differential survival and
reproduction, favoring helpful traits.
Darwin’s Observations and Inferences
5