Medical biology

medical biology first course  2017– 2018
define biology science
biology ( bios : life , logia : science ) is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.

q- who can you recognize between live and a live cells
q - what are biology recognize
biology generally recognizes that
cell as the basic unit of life,
genes as the basic unit of heredity,
evolution as the engine that propels the synthesis and creation of new species, also that all organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable and vital condition.
biology branches:
cell biology
microbiology
genetics
immunology
parasitology
histology

1- cell biology

cell biology is a branch of biology deals with the study of cells from morphology, structure, function and biochemical point of views, the idea and concept of cell biology evolved during 19th century as a result of gradual advancement in the field of microscopy and biochemistry. the cell is a smallest unites with complex physiochemical organization working in coordinate system to perform all life processes.


cell is the smallest unites with complex physiochemical organization working in coordinate system to perform all life processes.
cell theory concept
history
the term "cell" was first introduced by the english scientist , robert hooke, in 1665 while he cut a slice of cork and examined under a simple microscope, he observed several honey comb like structures in the cork he gave the term cell (l. cella = compartment or small room) for each compartment.

anton van leeuwenhoek was the first examine a droping of pond water under the microscope, he observed many tiny, motile organisms he called them "animalcules" meaning little animals. leeuwenhoek, was also the first describing various forms of bacteria.
in 1831 robert brown noticed a spherical body in the cell he gave it the name "nucleus”
in 1838, the german botanist schleiden reported that all plant tissues were composed of cells and he was considered to be the founder of the cell theory, then after one year 1839
the german zoologist schwann extended the finding of schleiden to animal tissues and both proposed the basis of cell theory
cell theory states
“the body of all living organisms is composed of cells, cell products and new cells are produced by the division of the pre – existing ones".
q- what are the ideas included in cell theory concept
the cells are the building block of structures in living things
the new cell is derived from other cells by division
the cell contains information that is used as instructions for growth, development and functioning
the cell is the functioning unit of life and the chemical reactions of life take place within cells.

types of compound microscope
the bright – field microscope
dark – field microscope
fluorescence microscope
phase- contrast microscope
the electron microscope
q- make a comparison between light and electron microscope.
electron m. light m.
1- can examine minute details of cell 1- examine the external shape

2- uses tv. screen to show the specimen 2- examine by lenses with variable sizes

3- magnification power of em. varies more
then 500 thousands times 3- magnification power of lm. is 1000x

4-used beam of electrons as a source of light 4- use light photons as a source of light

eukaryote and prokaryote cells
eukaryotic cells (eu: true, karyon : nucleus) have both true nucleus and complex organelles e.g., mitochondria, endoplasmic reticulum, centrioles, lysosomes, golgi complexes etc. , while prokaryotic cells ( pro : before , karyon : nucleus ) lack a true nucleus and complex membrane-bound organelles
eukaryote and prokaryote cells
question of lecture
although there are many differences between euk. and prok. but there are some similarities between them what are they?



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