Chapters 2, 3, 5, 20 – Mirna Hennawy – BIOA01H3 2012
Properties of Life
1. Organized Cells How Life Formed
2. Heritable Information (for reproduction) 1. Abiotic Synthesis
3. Show Growth
4. Respond to stimuli 2. Polymerization
3. Package molecules into protobionts to separate
5. Harness/Utilize energy
6. Exhibit Homeostasis internal chemistry
4. System of storing information and guide
7. Adapt to environmental change
Theories of Abiotic Synthesis
1. All cells are derived from other cells
Earth 2. All organisms are made of one or more cells 1. Primordial Soup: there was water vapor, H-
2O, CO 2 NH 3 and CH b4t no O . 2t was
3. Cells are the basic unit of life.
formed because environment was highly
Theory of evolution reducing (more reactive as chemicals try to
bond) and eventually made O .
All organisms, past or present, trace their 2
Relate all life on 2. Deep Sea Vents: Really hot environment of
ancestry back to one common ancestor. H , H S, CO and N , and the geochemical
2 2 2 2
Diversity: gradient generated lipids, protein,
Biological evolution through natural selection 3. Extraterrestrial Origins (Panspermia): Life
because of genetic errors during replication evolved from outer space, since meteorites
Diversity allows organisms to live in different contain carbonaceous material, amino acids
environments and to adapt to changing ones. and nucleotides.
1. Cells enclosed by lipid bilayer Clay Hypothesis: it has charged layers that
2. Genestic system based on DNA polymerizes monomers and also stores potential energy
3. System of information transfer (DNA that can be used for it.
Appearance of Protobionts
4. Protein assembly system by translation and
transfer of RNA
They are a group of abiotically produced organic
5. ATP molecule of chemical energy molecules surrounded by a membrane with
6. Metabolic pathway to generate ATP
unique internal chemistry and concentration.
7. Proteins as major structural and catalytic They may be generated spontaneously.
They are capable of simple reproduction and
Tree of Life metabolism.
They are similar to lysosomes (selectively
Phylogeny of organisms (genealogical permeable lipid bilayer)
relationships among species with a single ancestral
species as the base) System to Store Information and Guide Synthesis
Ribozymes were discovered: RNA molecules
that can act as enzymes Chapters 2, 3, 5, 20 – Mirna Hennawy – BIOA01H3 2012
Very small cells
Have catalytic properties due to folding (specific 1. 2.
for substrate) 3 common shapes: Sphere (coccus), Rod
(Bacillus), Spiral (Spirillus)
Double-stranded and Single stranded with
has deoxyribose ribose sugar (less
complex) Cell Structure
More Stable Less stable
Bacterial Cell Wall: Maintain shape of cell,
Base thymine helps Base uracil instead,
with DNA repair not as effective give protection and prevents bursting when
Single-Stranded hypotonic. They contain PEPTIDOGLYCAN
Double-stranded (harder to have DNA
(cross-linked sugars). Walls that have little
repair) peptidoglycan also have lipopolysaccharides
(LPS) that aren’t easily identifiable by
Protein RNA immune system (Gram-negative: pink).
Gram-positive (purple) have more
Fast rate of catalysis 10-1000 times slower
22 different amino 4 different nucleotide peptidoglycan.
acids bases (less variant) Sticky Capsule (glycocalyx): Surrounds
outer membrane, made of polysacharrides,
Amino acids interact (bonding sticky, cannot be identified by immune
chemically arrangements are
harder) system, protects from dessication, extreme
temperatures, invading viruses, antibiotics.
Pilli and Fimbriae: hair-like structure on
surface of bacteria, aids in attachment of
bacteria to host surfaces (required for
Obtain carbon from Obtain carbon from colonization during infection and initiation
of formation of biofilm)
organic molecules inorganic molecules
Produce CO 2 Produce O 2 Flagella: sensory (sensitive to external
Anoxygenic environment) and locomotive organelle
photosynthesis or (whip-like fashion), different than
respiration or Oxygenic eukaryotic flagella.
photosynthesis Genome: singular DNA molecule packed in
reduce water O nucleoid (no nucleus) and may also have
2 smaller rings (plasmids) to provide
resistance to antibiotics which replicate
Prokaryotes Eukaryotes independently and can be transferred
Lack membrane- Have membrane horizontally.
enclosed organelles enclosed organelles Ribosomes: smaller than eukaryotic ones,
No Nucleus Nucleus but protein synthesis is similar. Bacterial
Archaea, Bacteria Plants, Animals,
Fungi, Protists ribosomes are sensitive to antibiotics, but
archaeal and eukaryotic aren’t.
Genetic Diversity in Prokaryotes
Prokaryotic Morphology 1. Conjugation: DNA transfer through sex pilli Chapters 2, 3, 5, 20 – Mirna Hennawy – BIOA01H3 2012
2. Transformation: Uptake of genetic DNA from Nitrogen (component of proteins and
environment nucleotides) goes throug