Topic 1 Cellular Basis of Life, Cell Types, Techniques in Studying Cells

Cell and Molecular Biology

-Began with the invention of the microscope
-Credited with the invention of the compound microscope

Coined the term “cell”
(did this while observing cork cells)

Was not the first microscope maker, but
made some of the best early microscopes (Very high magnifications for the time – up to 300x)

Who published his observations in the book Micrographia (1665)

observed first living cells – ‘animalcules’

Who were the three scientists that their works compiled into one large idea called The Cell Theory

•  A lawyer turned botanist
• Said that all plants are made of cells and that a
plant embryo arose from a single cell(1838)

• Said that all cells are made from other cells (1855)
• Before this time it had been thought that cells could arise spontaneously from non-life

• Zoologist
• Said all animals are made of cells
• Concluded that the cells of plants and animals are similar structures (1839)

THE CELL THEORY

-Were the first human cells to be kept in culture for long periods of time and are still in use today.
-by George and Martha Gey of Johns Hopkins University in 1951

Who is the donor of HeLa cells

What are the types of cells?

What are the difference between prokaryotic and eukaryotic cell?

10 to 30 μm

1 to 5 μm

Escherechia coli

Saccharomyces cerevisiae

Arabidopsis thaliana

Caenorhabditis elegans

Drosophila melanogaster

Mus musculus

make image large

quality of image produced

difficult for nearly transparent objects

when objects are made bigger but their details do not become clearer

intact object, alive or dead, entire or a part of a large org.

thin slice; fixative (formaldehyde, alcohol, acetic acid)

The cone of light that illuminates the specimen is seen as a bright background against which the image of the specimen must be contrasted

Useful for: small, unstained specimens (e.g. living
cell), intracellular components, single cells or thin
cell layer. Optical handicap: result in loss of resolution; the image suffers from interfering halos and shading.

• a.k.a Nomarksi interference
• delivers an image that has an
apparent 3D quality

allows viewers to observe the location of certain
molecules (called fluorophores or fluorochromes)

absorb invisible, ultraviolet radiation and release a portion of the energy in the longer, visible wavelengths

charge-coupled device camera; low light, low noise (live cells)

Produces a thin plane situated within a much thicker specimen

utilizes photo switchable fluorescent proteins

atoms of the same elements
with the same number of p+ but
different number of n0

are radioactive when they contain an
unstable combination of protons and neutrons.

participate in the same reactions as nonradioactive species, but their location can be followed and the amount present can be measured.

Three main forms of radiation can be released by atoms during their disintegration.

measure amount of radioactivity

determine where a particular isotope is located

a process used to separate or concentrate materials suspended in a liquid medium.

a term for a variety of techniques in which a mixture of dissolved components is fractionated as it moves through some type of porous matrix

The separation of two proteins by DEAE- cellulose. In this case, a positively charged ion-exchange resin is used to bind the negatively charged protein

separates proteins (or nucleic acids) primarily on the basis of their effective size (hydrodynamic radius).

the first protein whose structure was determined by X-ray diffraction

took 22 years to solve the structure of hemoglobin, a task that today might take a few weeks.

the first chemically synthesized gene encoding
an average-sized protein prepared in 1981.

are molecules containing DNA sequences derived
from more than one source. can be formed
in a variety of ways or techniques.

a technique conceived by Kary Mullis of Cetus Corporation in 1983 that has become widely used to amplify specific DNA fragments without the need for bacterial cells.

are collections of cloned DNA fragments.; produced through DNA cloning.

are produced from total DNA extracted from nuclei and contain all of the DNA sequences of the species.

are derived from DNA copies of an RNA population, are typically produced from messenger RNAs present in a particular cell type and thus correspond to the genes that are active in that type of cell.

process of determining phenotype (i.e., function) based on the knowledge of genotype.

are proteins produced by lymphoid tissues in response to the presence of foreign materials, or antigens.

Used to identify and locate DNA sequences complementary to another piece of DNA called PROBE

Used to locate and identify mRNA sequences complementary to a PROBE