Cell Biology Lecture Notes
Introduction:
A. Definition of a cell: fundamental structural and functional unit of all living organisms
B. Characteristics of cells:
1) Contain highly organized molecular and biochemical systems and are used to store information
2) Use energy
3) Capable of movement
4) Sense environmental changes
5) Can duplicate (transfer genetic information to offspring)
6) Capable of self-regulation
-Most cells are microscopic (invisible to the naked eye) and thus, a microscope is needed to view most cells.
C) History:
-Discovery of the cell followed by the development of the microscope
A. 1665-Robert Hooke- observed cells from the fruiting bodies of fungi
B. Anton van Leewenhoek- observed a variety of cells and called them "animalcules"
C. 1830’s-Theodor Schwann and Matthias Schleiden developed the cell theory
-Cell Theory states:
1. All living organisms are composed of cells
2. Cells are the functional units of living organisms
3. Cells arise from preexisting cells via division
D) Louis Pasteur-developed the theory of spontaneous generation that is that cells could develop from non-living
matter
-Also worked on problem associated with the fermentation of French wine
-1857-developed a partial sterilization process called pasteurization- involves heating at a
moderate temperatures to reduce the number of living microorganisms
E) 1865-Mendel-demonstrated that cellular traits (phenotypes) were inherited
- Seed shape and color in garden peas
- Named "Father of Genetics"
F) 1871-Johan Freidrick Miescher-isolated nucleic acids from cells "nuclein"
,G) 1889-R.Altman-purified nucleic acids
H) 1944-Oswald Avery, Colin MacLeod, and MacLyn McCarty-
-Demonstrated that DNA was the heredity molecule
-DNA could transform bacterial cells
I) 1952-Alfred Hershey and Martha Chase-also demonstrated that DNA was the heredity molecule
-Radioactive DNA from a virus was able to infect and transform bacterial cells
J) 1953-James Watson and Francis Crick-developed the 3-D structure of DNA
K) 1958-Mattew Meselson and Frank Stahl-demonstrated that DNA replicated by a semi conservative method
L) 1961-Brenner, Jacob, Meselson-discovered RNA
M) 1966-Nirenberg and Khorana-elucidated the chemical nature of the genetic code
N) 1972-1973-Berg, Boyer, and Cohen- discovered gene cloning
O) 1975-Gilbert and Sanger-developed chemical techniques to rapidly sequence DNA
Cell Structure:
I. Most cells are microscopic and cannot be seen by the naked eye.
II. Microscopes were developed to visualize cells.
III. Resolution is the minimum distance where 2 objects can be visually separated
-Unresolved
-Partially resolved
-Resolved
-Depends on:
a. Wavelength of light
b. Refractive index of the medium
c. Of the light
-The naked eye can resolve two separate objects separated by 200 um
Metric system:
-1 meter = 3.3 feet, 1 km = 103 m, 1cm = 10-2 m, 1mm = 10-3 m, 1um = 10-6 m, 1nm = 10-9 m, 1 A = 10-10 m, 1pm =
10-12 m
,IV. Light microscope:
-Can resolve two objects 100-200 nm apart (including cells and large sub cellular organelles)
-Uses different light sources and patterns of image formation
a. Bright field d) differential interference
b. Dark field e) fluorescence c) phase contrast
V. Electron Microscope:
-Uses a beam of electrons (e-) rather than light as an illumination source
A. Transmission Electron Microscope (TEM)
-Electrons forming the image focused through the specimen
-Short wavelength of e- beam improves the resolution of TEM to 5 A (.5nm)
-Can resolve small sub cellular organelles and large proteins
B. Scanning Electron Microscope (SEM)
-Used to examine surfaces of cells or isolated cellular structures
-e- beam "scans" the specimen
-Resolution 5 to 10 nm
Prokaryotic Cells- small and primitive bacteria and blue-green algae (cyanobacteria)
Greek: Pro=before karyon=nucleus
-Lacks specialized internal membrane-bound compartments known as organelles
-Cell membrane- functions in transport, the movement of substances in and out of the cell, and in
energy production (breakdown of large molecules, photosynthesis)
-Cell wall- gives structural strength (rigidity) to the cell
-Capsule- jelly-like substance which protects the cell wall from environmental damage
-Nucleiod- contains a single circular molecule of DNA (stores genetic information)
-Cytoplasm- region surrounding the nucleiod and within the cell membrane
-Contains ribosomes and RNA (site of protein synthesis)
-Vacuole (vesicles)(blue-green algae)-site of photosynthesis (storage)
-Flagellum- protein fiber the functions in movement
, Eukaryotic Cell- (eu=true karyon=nucleus)
1. Possesses a complex membrane system
2. Has a true nucleus
3. Distinct membrane-bound intracellular compartments called organelles
-Nucleus- dark-staining body within the cell by enclosed an intracellular membrane called the
nuclear envelope
-Nuclear envelope contains pores, which are filled with a ring of proteins called annulus
-Contains DNA in the form of chromatin fibers
-DNA is linear (linear DNA + proteins = chromosome)
-Nucleolus- a cell organelle in the nucleus that disappears during part of cell division. Contains rRNA genes
-Nucleus also contains RNA (mRNA, rRNA, and tRNA)
-Transcription- conversion of genetic information from DNA to RNA occurs in the nucleus
-DNA replication-duplication of genetic material
-Cytoplasm: major portion of the protoplasmic substance within the cell membrane
a. Ribosomes-a cytoplasmic particle that contains RNA and protein and is involved in the process of
protein synthesis
-Translocation-process which takes place in the cytoplasm and converts genetic information in RNA into
proteins
-Ribosomes can either be freely suspended in the cytoplasm or attached to intracellular
membranes
a. Endoplasmic reticulum (ER)- a network of intracellular membranes where secreting proteins are
synthesized
-Rough
ER- the
ER +
ribosom
es
-Smooth
ER- the
ER
without
ribosom
es
-
Function
Introduction:
A. Definition of a cell: fundamental structural and functional unit of all living organisms
B. Characteristics of cells:
1) Contain highly organized molecular and biochemical systems and are used to store information
2) Use energy
3) Capable of movement
4) Sense environmental changes
5) Can duplicate (transfer genetic information to offspring)
6) Capable of self-regulation
-Most cells are microscopic (invisible to the naked eye) and thus, a microscope is needed to view most cells.
C) History:
-Discovery of the cell followed by the development of the microscope
A. 1665-Robert Hooke- observed cells from the fruiting bodies of fungi
B. Anton van Leewenhoek- observed a variety of cells and called them "animalcules"
C. 1830’s-Theodor Schwann and Matthias Schleiden developed the cell theory
-Cell Theory states:
1. All living organisms are composed of cells
2. Cells are the functional units of living organisms
3. Cells arise from preexisting cells via division
D) Louis Pasteur-developed the theory of spontaneous generation that is that cells could develop from non-living
matter
-Also worked on problem associated with the fermentation of French wine
-1857-developed a partial sterilization process called pasteurization- involves heating at a
moderate temperatures to reduce the number of living microorganisms
E) 1865-Mendel-demonstrated that cellular traits (phenotypes) were inherited
- Seed shape and color in garden peas
- Named "Father of Genetics"
F) 1871-Johan Freidrick Miescher-isolated nucleic acids from cells "nuclein"
,G) 1889-R.Altman-purified nucleic acids
H) 1944-Oswald Avery, Colin MacLeod, and MacLyn McCarty-
-Demonstrated that DNA was the heredity molecule
-DNA could transform bacterial cells
I) 1952-Alfred Hershey and Martha Chase-also demonstrated that DNA was the heredity molecule
-Radioactive DNA from a virus was able to infect and transform bacterial cells
J) 1953-James Watson and Francis Crick-developed the 3-D structure of DNA
K) 1958-Mattew Meselson and Frank Stahl-demonstrated that DNA replicated by a semi conservative method
L) 1961-Brenner, Jacob, Meselson-discovered RNA
M) 1966-Nirenberg and Khorana-elucidated the chemical nature of the genetic code
N) 1972-1973-Berg, Boyer, and Cohen- discovered gene cloning
O) 1975-Gilbert and Sanger-developed chemical techniques to rapidly sequence DNA
Cell Structure:
I. Most cells are microscopic and cannot be seen by the naked eye.
II. Microscopes were developed to visualize cells.
III. Resolution is the minimum distance where 2 objects can be visually separated
-Unresolved
-Partially resolved
-Resolved
-Depends on:
a. Wavelength of light
b. Refractive index of the medium
c. Of the light
-The naked eye can resolve two separate objects separated by 200 um
Metric system:
-1 meter = 3.3 feet, 1 km = 103 m, 1cm = 10-2 m, 1mm = 10-3 m, 1um = 10-6 m, 1nm = 10-9 m, 1 A = 10-10 m, 1pm =
10-12 m
,IV. Light microscope:
-Can resolve two objects 100-200 nm apart (including cells and large sub cellular organelles)
-Uses different light sources and patterns of image formation
a. Bright field d) differential interference
b. Dark field e) fluorescence c) phase contrast
V. Electron Microscope:
-Uses a beam of electrons (e-) rather than light as an illumination source
A. Transmission Electron Microscope (TEM)
-Electrons forming the image focused through the specimen
-Short wavelength of e- beam improves the resolution of TEM to 5 A (.5nm)
-Can resolve small sub cellular organelles and large proteins
B. Scanning Electron Microscope (SEM)
-Used to examine surfaces of cells or isolated cellular structures
-e- beam "scans" the specimen
-Resolution 5 to 10 nm
Prokaryotic Cells- small and primitive bacteria and blue-green algae (cyanobacteria)
Greek: Pro=before karyon=nucleus
-Lacks specialized internal membrane-bound compartments known as organelles
-Cell membrane- functions in transport, the movement of substances in and out of the cell, and in
energy production (breakdown of large molecules, photosynthesis)
-Cell wall- gives structural strength (rigidity) to the cell
-Capsule- jelly-like substance which protects the cell wall from environmental damage
-Nucleiod- contains a single circular molecule of DNA (stores genetic information)
-Cytoplasm- region surrounding the nucleiod and within the cell membrane
-Contains ribosomes and RNA (site of protein synthesis)
-Vacuole (vesicles)(blue-green algae)-site of photosynthesis (storage)
-Flagellum- protein fiber the functions in movement
, Eukaryotic Cell- (eu=true karyon=nucleus)
1. Possesses a complex membrane system
2. Has a true nucleus
3. Distinct membrane-bound intracellular compartments called organelles
-Nucleus- dark-staining body within the cell by enclosed an intracellular membrane called the
nuclear envelope
-Nuclear envelope contains pores, which are filled with a ring of proteins called annulus
-Contains DNA in the form of chromatin fibers
-DNA is linear (linear DNA + proteins = chromosome)
-Nucleolus- a cell organelle in the nucleus that disappears during part of cell division. Contains rRNA genes
-Nucleus also contains RNA (mRNA, rRNA, and tRNA)
-Transcription- conversion of genetic information from DNA to RNA occurs in the nucleus
-DNA replication-duplication of genetic material
-Cytoplasm: major portion of the protoplasmic substance within the cell membrane
a. Ribosomes-a cytoplasmic particle that contains RNA and protein and is involved in the process of
protein synthesis
-Translocation-process which takes place in the cytoplasm and converts genetic information in RNA into
proteins
-Ribosomes can either be freely suspended in the cytoplasm or attached to intracellular
membranes
a. Endoplasmic reticulum (ER)- a network of intracellular membranes where secreting proteins are
synthesized
-Rough
ER- the
ER +
ribosom
es
-Smooth
ER- the
ER
without
ribosom
es
-
Function
