Module 1
The cell, the unit of life
• Life is the natural phenomenon that distinguish all organisms from inanimate objects.
o Recall: 7 Properties of Life depict what is living and what is not (ie. Virus are
infectious particles vs. Bacteria are living organisms)
§ Viruses have no cellular organization, internal metabolism (depends on
host) and does not grow or develop. They cannot replicate outside of a
cell. Have an RNA or DNA genome surrounded by a protein coat (capsid)
or membranous envelope.
§ Prions are infectious agents that result from a misfold of a cellular
protein. Convert other proteins into prions (degenerative disease of the
nervous system)
§ Viroids are small infectious circular RNA molecules that replicate using
the replication machinery of their plant host cell. Do not code any protein
but can be transmitted between cells and individual plants (more popular
in plants).
•
• Cell theory
o Cell = smallest basic structural, functional and biological unit of life
o All cells derive from preexisting cells
o All organisms are made of one or more cells (uni or multicellular)
§ The number of cells an organism has depicts its size, shape and
behaviors.
• Recall there are benefits to multicellularity (reproduction,
protection, increase in surface are for diffusion - absorb nutrient
and specialization depending on what they are exposed to, longer
lifespan, specialization into cell types, tissues and organs, feeding,
more efficient locomotion)
,• Multicellularity
o Colonial Hypothesis: Colonies form through cooperation of unicellular organism
of the same species, with cells failing to separate or separate and rejoin.
Allowing specialization to occur.
• Life on Earth uses Carbon
o Highly abundant
o Small molecular weight and size
o Can bind to four other atoms to form reactive and stable molecules (ORGANIC)
o Polymerization
• C,O,H,N
o Proteins
o Carbs
o Fatty acids
o Nucleic acids
• Origin of Life
o Organic molecules necessary for the first step in the Origin of life may have been
synthesized from abiotic molecules on the early earth.
§ A lot of energy available near deep sea vents (hot, near plates).
§ Raw materials in early atm. (methane, ammonia, hydrogen, some energy
from lightening)
§ Clay as a mineral catalyst for the self-polymerization of RNA
• RNA World: RNA can self-replicate (without a protein, protein is
synthesized from RNA) and is assumed to be in the first living
cells/organisms.
o First living organism were cyanobacteria which formed
stromatolites
o
• DNA is more stable.
, • Cellular Functions
o Contain and transmit genetic material
o Acquisition and conversion of energy
o Feeding and absorption of energy
o Structure and support
o Communication and response to environmental stimuli
o Barrier and defense mechanism (biotic or abiotic, environmental stresses)
o Transport molecules
§ Osmoregulation
§ Gas Exchange
o Reproduction (gametes)
• Multicellular Organisms have cell organized in tissues and tissues organized in organs.
o More specialization (pro of multicellularity)
o Some cells are better suited for a certain function
o Cells, tissues and organs have very specific functions
• Central Dogma (proposed by Francis Crick)
o Information is transferred between nucleic acid and nucleic acid to protein but
NEVER protein to protein or protein to nucleic acid.
o
• DNA can be transferred to other DNA molecules (proposed by James Watson – does not
contradict what Crick said)
•
• 3 Domains – common ancestor was prokaryote
1. Eukarya
§ Dinoflagellates (Red Sea due to access growth from nutrients,
bioluminescent)
2. Archaea: prokaryotes, not bacteria
§ Extremophiles (acidic, not, high salinity)
§ Methanogens: use CO2 and H2 to produce methane
3. Bacteria
• Ribosomal proteins
o Critical for protein synthesis
The cell, the unit of life
• Life is the natural phenomenon that distinguish all organisms from inanimate objects.
o Recall: 7 Properties of Life depict what is living and what is not (ie. Virus are
infectious particles vs. Bacteria are living organisms)
§ Viruses have no cellular organization, internal metabolism (depends on
host) and does not grow or develop. They cannot replicate outside of a
cell. Have an RNA or DNA genome surrounded by a protein coat (capsid)
or membranous envelope.
§ Prions are infectious agents that result from a misfold of a cellular
protein. Convert other proteins into prions (degenerative disease of the
nervous system)
§ Viroids are small infectious circular RNA molecules that replicate using
the replication machinery of their plant host cell. Do not code any protein
but can be transmitted between cells and individual plants (more popular
in plants).
•
• Cell theory
o Cell = smallest basic structural, functional and biological unit of life
o All cells derive from preexisting cells
o All organisms are made of one or more cells (uni or multicellular)
§ The number of cells an organism has depicts its size, shape and
behaviors.
• Recall there are benefits to multicellularity (reproduction,
protection, increase in surface are for diffusion - absorb nutrient
and specialization depending on what they are exposed to, longer
lifespan, specialization into cell types, tissues and organs, feeding,
more efficient locomotion)
,• Multicellularity
o Colonial Hypothesis: Colonies form through cooperation of unicellular organism
of the same species, with cells failing to separate or separate and rejoin.
Allowing specialization to occur.
• Life on Earth uses Carbon
o Highly abundant
o Small molecular weight and size
o Can bind to four other atoms to form reactive and stable molecules (ORGANIC)
o Polymerization
• C,O,H,N
o Proteins
o Carbs
o Fatty acids
o Nucleic acids
• Origin of Life
o Organic molecules necessary for the first step in the Origin of life may have been
synthesized from abiotic molecules on the early earth.
§ A lot of energy available near deep sea vents (hot, near plates).
§ Raw materials in early atm. (methane, ammonia, hydrogen, some energy
from lightening)
§ Clay as a mineral catalyst for the self-polymerization of RNA
• RNA World: RNA can self-replicate (without a protein, protein is
synthesized from RNA) and is assumed to be in the first living
cells/organisms.
o First living organism were cyanobacteria which formed
stromatolites
o
• DNA is more stable.
, • Cellular Functions
o Contain and transmit genetic material
o Acquisition and conversion of energy
o Feeding and absorption of energy
o Structure and support
o Communication and response to environmental stimuli
o Barrier and defense mechanism (biotic or abiotic, environmental stresses)
o Transport molecules
§ Osmoregulation
§ Gas Exchange
o Reproduction (gametes)
• Multicellular Organisms have cell organized in tissues and tissues organized in organs.
o More specialization (pro of multicellularity)
o Some cells are better suited for a certain function
o Cells, tissues and organs have very specific functions
• Central Dogma (proposed by Francis Crick)
o Information is transferred between nucleic acid and nucleic acid to protein but
NEVER protein to protein or protein to nucleic acid.
o
• DNA can be transferred to other DNA molecules (proposed by James Watson – does not
contradict what Crick said)
•
• 3 Domains – common ancestor was prokaryote
1. Eukarya
§ Dinoflagellates (Red Sea due to access growth from nutrients,
bioluminescent)
2. Archaea: prokaryotes, not bacteria
§ Extremophiles (acidic, not, high salinity)
§ Methanogens: use CO2 and H2 to produce methane
3. Bacteria
• Ribosomal proteins
o Critical for protein synthesis
