Unit 1 Intro to Radiobiology

the branch of science concerned with the effects of ionizing radiation on living systems

list the four components of the cell theory

smallest unit of protoplasm capable of independent existence.
the basic unit of any living organism.

group of cells with the same function

groups of tissues that work together to perform a specialized function

group of organs that work together to perform a common function

systems grouped together

any member of a large class of chemical compounds whose molecules contain carbon

four major classes of organic compounds

basic building blocks of cells
ex. insulin, albumin, hemoglobin, enzymes
composed of amino acids

provide energy necessary for cellular functions
ex. starch, glycogen, lactose, sucrose
composed of carbon, hydrogen, oxygen

contains genetic materials
controls cell division and multiplication and biochemical reactions that occur within the living cell
composed of sugar, phosphate, nitrogenous bases, hydrogen

role in protein synthesis
composed of sugar, phosphate, nitrogenous bases

structural parts of cell membranes.
act as reservoirs for long term storage of energy
insulate and guard the body against the environment
support and protect organs
provide essential substances necessary for growth and development
lubricate the joints
assist in the digestive process

the protoplasm that exists outside the cells nucleus. makes up the majority of the cell and contains large amounts of all the cells molecular components with the exception of DNA

building up

breaking down

contains genetic information
directs all cellular functions

specialized structures within the cell performing specific functions

monitors exchanges between cell and environment
location: cytoplasm

enables the cell to communicate with the extra cellular environment and transfer food and molecules from one part of the cell to another
-located in cytoplasm

rough ER contains

controls protein synthesis
contains uracil
location:cytoplasm and nucleus

carries a code of DNA to a ribosome where it is transferred to tRNA

searches the cytoplasm for the amino acid and carries it to the ribosome for protein synthesis

exists only in ribosomes
assist in the linking of mRNA to the ribosome
to facilitate protein synthesis

manufacture the various proteins that cells require using the blueprints provided by mRNA
location:cytoplasm

produce energy by oxidizing carbohydrates and lipids
major energy production center; aerobic respiration
location: cytoplasm

a protein that encourages a biochemical reaction

contains enzymes capable of breaking down proteins and carbohydrates and destroying the cell
location: cytoplasm

concentration and segregation of products for secretion; carbohydrate synthesis
location: cytoplasm

separation of nucleus and cytoplasm. permits selective passage of molecules from nucleus to cytoplasm and vice versa
location:nucleus

manufactures and holds large amounts of RNA

directs all cellular activity 
contains genetic info in code form
contains nitrogenous bases
location: nucleus

Four nitrogenous bases

bases bond to each other through

bases bond to sugar molecules on

a structural component or building block of DNA and RNA
consists of a base + a molecule of sugar+ phosphoric acid

directs cellular activities
contains DNA
functional and physical unit of heredity passed from parent to offspring
location: nucleus

directs cellular activities
contains genes
location:nucleus

the number of chromosomes in somatic cells

the number of chromosomes in a normal somatic cells for a given species

human somatic cells have how many pairs of chromosomes

the number of chromosomes in a sperm of egg cell

refers to the number of chromosomes in a normal germ cell for a specific species

two types of cellular division

multiplication process where one cell divides and forms two or more cells

a parent cell divides to form two daughter cells identical to the parent cell

period of cell growth that occurs before mitosis
contains three intervals: G1, S, G2.

the first phase of cell division
nucleus enlarges
DNA complex coils up tightly
chromatids become visible attached at the centromere
spindle fibers appear

Nucleolus and nucleus membrane disappear
spindle fibers attach to chromatid
chromatids align on the equatorial plate

centromeres migrate in opposite directions
furrow appears

nuclear membrane and both nuclei appear
chromatids uncoil
cytoplasm and organelles divide equally
cell division is complete

cell division that reduces the number of chromosomes in each daughter cell to half the number of chromosomes in the parent cell

doubling the amount of genetic material

a mature reproductive cell capable of function in fertilization or conjugation

oogonium

spermatogonium

does not include chromosomal replication

in general, cell are most            in late M and G2 phases, and most               in late S

invented the diode tube with a partial vacuum, which Roentgen was using when he discovered xray.

produced the first radiography. this was a shadow of coins on a photographic plate. he did not know what had caused the shadow

discovered xrays

found that uranium emitted rays that passes through paper and darkened photographic film

announced the discovery of radium, which also emitted penetrating rays.             applied the term radioactivity to the behavior of these materials

noticed a skin reaction induced by radium he had been carrying in a tube in his vest pocket

deliberately exposed a small area of skin to radium and observed effects

began experimental radiobiology by exposing rabbits testes to xrays and documenting efffects

the radiosensitivity of cells is directly proportional to their reproductive activity and inversely proportional to the differntiation

Laid the groundwork for modern radiotherapy by placing the principle of fractionation on a firm clinical basis

invented the cyclotron, a machine capable of accelerating charged particles to very high speeds. these charged particles were used as bullets and shot into the nuclei of target atoms to study the nuclear structure. used today to produce nucleotides for nuclear medicine studies.

studied indirect effects of ionizing radiation

discovered that oxygen increases the effects of ionzing radiation on living matter (oxygen effect)

studied both indirect effect and oxygen effect on radiation

produced the first successful culture of mammalian cells in artifical media (hela cells). exposed these cells to radiation in vitro and plotted cell survival curve

showed that cells can sometimes recover from sublethal doses of radiation

chemical building materials for all living things
metabolism
reception and processing of food and oxygen
elimination of waste products

compounds that do not contain carbon
most important are                

molecule consisting of large number of atoms