1- CELLS
7 processes of life
1) Metabolism: chemical reac ons that convert energy from one form into another.
- Catabolism → large molecules into smaller units, releases energy.
- Anabolism → smaller units into larger molecules, requires energy.
2) Reproduc on: hereditary molecules that can be passed from parent to o spring.
- Sexual → needs 2 parents and gametes.
- Asexual → no need for gametes, only 1 parent needed.
3) Homeostasis: the maintenance of a constant internal environment.
4) Growth: the development of an organism.
5) Response: reac on to s muli in the environment needed for survival.
6) Excre on: the release of toxic or waste chemical compounds of the metabolic process.
7) Nutri on: the ability of an organism to nd or make a substrate for respira on.
Cell theory
● → all organisms are made of cells, cells are the smallest independent (can do all 7 processes of
life) unit of life, and all cells come from preexis ng cells.
● Pasteur’s experiment → he boiled a nutrient broth to sterilize it by killing all microorganisms
present, and then displayed the broth in 3 di erent asks. One was open, one sealed and one
curved (which prevents outside air from entering). A er an incuba on period, he observed that
bacteria was only present in the open ask’s broth.
● This experiment was essen al because it proved one of the principles of cell theory: all cells
come from preexis ng cells. Pasteur showed that living cells cannot spontaneously appear in a
sterile environment. It’s possible for them to appear only a er an exposure to preexis ng cells.
Microscopes
● Light microscope → magni es the image of an object using light.
● Uses convex lenses.
● Objects smaller than light’s wavelength (700 nanometers) cannot be seen
● 1 nanometer = 1/1000000 mm
● The solu on to this limita on → electron microscope.
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, Di erences between eukaryo c and prokaryo c cells
Eukaryotes Prokaryotes
Mul cellular organisms Unicellular organism
Membrane-bound nucleus and organelles No membrane around nucleus and organelles, has
a nucleoid instead of a nucleus
Mitochondria present No mitochondria
Cytoskeleton present No cytoskeleton
No agellum Flagellum
No cell wall, no pilus Has cell wall and pilus
Reproduc on through cell division Reproduc on through binary ssion
Prokaryo c cells
● Bacteria and cyanobacteria
● No nucleus
● No membrane-bound organelles
● Single cells or cluster of cells
● Cell wall NOT made of cellulose, instead
made of pep doglycan (murein)
● Circular DNA → plasmid
● 70S ribosomes (we have 80S)
Eukaryo c cells
● “Eu-kario” → proper nucleus
● Contain membrane-bound organelles →
mitochondria, chloroplasts, golgi, RER and
SER, lysosomes, ribosomes.
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7 processes of life
1) Metabolism: chemical reac ons that convert energy from one form into another.
- Catabolism → large molecules into smaller units, releases energy.
- Anabolism → smaller units into larger molecules, requires energy.
2) Reproduc on: hereditary molecules that can be passed from parent to o spring.
- Sexual → needs 2 parents and gametes.
- Asexual → no need for gametes, only 1 parent needed.
3) Homeostasis: the maintenance of a constant internal environment.
4) Growth: the development of an organism.
5) Response: reac on to s muli in the environment needed for survival.
6) Excre on: the release of toxic or waste chemical compounds of the metabolic process.
7) Nutri on: the ability of an organism to nd or make a substrate for respira on.
Cell theory
● → all organisms are made of cells, cells are the smallest independent (can do all 7 processes of
life) unit of life, and all cells come from preexis ng cells.
● Pasteur’s experiment → he boiled a nutrient broth to sterilize it by killing all microorganisms
present, and then displayed the broth in 3 di erent asks. One was open, one sealed and one
curved (which prevents outside air from entering). A er an incuba on period, he observed that
bacteria was only present in the open ask’s broth.
● This experiment was essen al because it proved one of the principles of cell theory: all cells
come from preexis ng cells. Pasteur showed that living cells cannot spontaneously appear in a
sterile environment. It’s possible for them to appear only a er an exposure to preexis ng cells.
Microscopes
● Light microscope → magni es the image of an object using light.
● Uses convex lenses.
● Objects smaller than light’s wavelength (700 nanometers) cannot be seen
● 1 nanometer = 1/1000000 mm
● The solu on to this limita on → electron microscope.
ti titi ti ti ti tifiti flfi ff ti flft ft ti ff ti ti
, Di erences between eukaryo c and prokaryo c cells
Eukaryotes Prokaryotes
Mul cellular organisms Unicellular organism
Membrane-bound nucleus and organelles No membrane around nucleus and organelles, has
a nucleoid instead of a nucleus
Mitochondria present No mitochondria
Cytoskeleton present No cytoskeleton
No agellum Flagellum
No cell wall, no pilus Has cell wall and pilus
Reproduc on through cell division Reproduc on through binary ssion
Prokaryo c cells
● Bacteria and cyanobacteria
● No nucleus
● No membrane-bound organelles
● Single cells or cluster of cells
● Cell wall NOT made of cellulose, instead
made of pep doglycan (murein)
● Circular DNA → plasmid
● 70S ribosomes (we have 80S)
Eukaryo c cells
● “Eu-kario” → proper nucleus
● Contain membrane-bound organelles →
mitochondria, chloroplasts, golgi, RER and
SER, lysosomes, ribosomes.
ffflti tititi ti fiti ti
