| Question | Answer |
| the study of effects of radiation on humans | radiobiology |
| suggests that low levels of radiation(<50 mGy or 5 rad)provides a protective effect by simulating molecular repair mechanisms | radiation hormesis |
| at what level do all effects of radiation begin | at the atomic level of a structure |
| what are the three catagories of human response to radiation | *early *late(chronic/delayed) *embryo-fetal |
| what are some symptoms of early effects of radiation | *acute radiation syndrome *local tissue damage *hematologic damage(drops blood count) *cytogenic(cellular change) |
| what are some symptoms of late/delayed effects of radiation | *cancer
*local tissue damage
*life span shortening
*genetic effects |
| what is a point lesion | change in genetic code |
| what does prodrome mean | early symptom |
| what is something if it is latent | dormant |
| what are the three stages of radiation effects | *prodrome
*latency
*manifest |
| what is something if it is acute | sudden onset |
| what are the dose effects discussed | *250 mSv= drop in cell count
*1500 mSv= erythema adn NVD
*3000 mSv= lethal dose, 50% of exposed population will die within 30 days(LD 50/30) |
| how many levels of cellular composition are there | 7 |
| what is the 1st level of cellular composition | chemical or atomic |
| what happens at level 1(chemical or atomic) | interactions between elements to combine into molecules |
| what is a large molecule with a major function | macromolecule |
| what is homeostasis | constancy of internal environment |
| what is catabolism | breakdown of molecules |
| what is anabolism | building up of molecules |
| what is metabolism | process of building up and breaking down of molecules (catabolism and anabolism working together) |
| what is the composition of a macromolecule | *80% water
*15% proteins
*2% lipids
*1% carbohydrates
*1% RNA
*1% DNA |
| what is the importance of water within a cell | *provides form and cell shape
*maintains temperature
*enters into biochemical reactions |
| what is the only non-organic molecule in the body | water |
| what role does protein play within a cell | *chain of 22 amino acids connected by peptide chain
*provides structure and support |
| what do enzymes do | allow biochemical reactions |
| what do hormones do | regulate and control body functions |
| what are antibodies | primary defense against antigens |
| antigen | foreign substance that causes body to produce antibodies, when introduced to body |
| what role do lipids play within the cell | *structural component of cell membrane
*thermal insulator
*provide energy storage and fuel |
| what role do carbohydrates play within the cell | *fuel for cell metabolism
*provide shape and stability for cells/tissues
*poly or monosaccharides |
| what is the role of RNA within a cell | *Single strand(helix)
*found in nucleus and cytoplasm
*messanger and transfer RNA
*protein synthesis |
| what is the role of DNA within a cell | *found only in nucleus
*double helix
*hold nitrogenous bases
*contain 5-carbon sugar(pentose, which is a monosaccharide)
*phosphoric acid bonds
*contains all hereditary info
*found on chromosome
*most radiosensitive MM
*contains codon |
| what makes up the side rails of DNA ladder | alternating sugar and phosphate molecules |
| what makes up rungs of DNA ladder | pairs of nitrogenous bases(one purine and one pyrimidine) |
| a series of 3 adjacent bases in one polynucleotide chain of a DNA or RNA molecule, which codes for a specific amino acid | codon |
| basic unit of matter, consists of nucleus and surrounded by negatively charged electrons | atom |
| (A#) number of protons and neutrons in a nucleus | atomic mass |
| (Z#) number of protons in a nucleus | atomic number |
| two atoms that have same number of protons but different number of neutrons/same atomic number different atomic mass | isotope |
| group of 8 e- in outermost shell, cannot chemically combine | octet |
| determines the chemical binding ability of an atom | valence |
| constancy of internal environment | homeostasis |
| what is the second level of cellular composition | organelles |
| what is an organelle | small organ within a cell with specific functions |
| what are the different types of organelles within a cell | *endoplasmic reticulum
*golgi aparatus
*lysosomes
*mitochondria
*ribosomes |
| organelle found within the cytoplasm that functions as channels whereby nucleus communicates with cytoplasm | endoplasmic reticulum |
| organelle that concentrates and packages secretion products (mailman) | golgi apparatus |
| organelle that contains enzymes capable of digesting cellular fragments and sometimes the cell itself | lysosomes |
| where macromolecules are digested to produce cellular energy, known as the workhorse or engine of the cell | mitochodria |
| small organelle, which is the site of protein synthesis | ribosomes |
| what is the third level of cellular composition | the cell |
| what is a cell | basic living subunit, within any living organism |
| has single helix strand, found in and outside of nucleus, and comes in messanger, and transfer varieties | ribonulceic acid(RNA) |
| the most radiosensitive of all macromolecules, since it contains genetic info. found inside of nucleus and controls cell function | deoxyribonucleic acid(DNA) |
| this part of the cell is made of lipid-protein that selectively allows small molecules and water to diffuse and provide structure and form | cell membrane |
| outside of nucleus but within plasma membrane, contains organelles and all living things within a cell, made of 70%-90% water | cytoplasm/protoplasm |
| what are the basic functions of the cell membrane | *protein synthesis- genetic code contained in DNA tells which protein to be produced
*code transfers to mRNA within nucleus, mRNA leaves via ER on way to ribosome, where it is tranferred to tRNA. tRNA searches cytoplasm for the coded amino acid. |
| what is the next step after tRNA finds the amino acid that matches the code it carries | it attaches to the amino acid and carries it to the ribosome, where it joins other amino acids in sequence by peptide bonds to form protein molecule. |
| what happens if there is any interference with any of the sequences of protein synthesis | could result in damage to the cell |
| all cells of the body except the oogonium and the spermatogonium | somatic cells |
| what type of cells are oogonium(ovum) and spermatogonium(sperm) | genetic cells |
| which type of cells undergo mitosis | somatic cells |
| what are the phases of mitosis | *prophase
*Metaphase
*anaphase
*telophase |
| *genetic material forms strands in nucleus, the 1st sign of chromosome formation
*nucleus and chromosomes enlarge
*membrane begins to break down
*chromosomes move toward equatorial plate | prophase |
| *chromosomes at equatorial plate
*membrane completely broken down
*chromatids attach to spindle fibers by centromere
*duplication | metaphase |
| *splitting of each chromosome at centromere, so that a centromere and two chromatids are attached to a spindle fiber, which is attached to a spindle or pole
*newly formed chromosomes migrate to opposite poles or spindles | anaphase |
| *structural chromosomes disappear into mass of DNA
*nuclear membrane is pinched in middle and two new nuclei are formed | telophase |
| *towards the end of telophase
*cytoplasm is divided into two equal parts(daughter cells), each one keeping one of the nuclei
*not a part of mitosis, but a seperate part of proliferation | cytokinesis |
| what is the life cycle of a cell | *gap 1-preperation for synthesis(part of interphase)
*DNA is synthesized(part of interphase)
*gap 2-preperation for mitosis(part of interphase)
*mitosis |
| genetic cells undergo what type of proliferation | meiosis- reduction division*chromosomes are reduced from 46 to 23 after to cycles(mother cells divide into two daughter cells, which are then each divided into two grandaughter cells, each with 23 chromosomes) |
| *exchange of chromosomal material between chromatids, resulting in changes to genetic make-up and inherited traits*happens in second cycle of meiosis | crossing over |
| what happens in level 4 of cellular organization | groups of similar cells form tissues |
| what happens in level 5 of cellular organization | two or more tissues with common function form organs |
| what happens in level 6 of cellular organization | groups of organs form the 10 body systems |
| what are the 10 body systems | *immune
*skeletal
*nervous
*digestive
*cardiovascular
*integumentary
*respiratory
*endocrine
*reproductive
*excretory |
| what happens at level 7 of cellular organization | living organism |
| what are the most radiosensitive cells in the body | *lymphocytes
*spermatogonia
*erythroblasts |
| what are the most radioresistant cells in the body | *muscle cells
*nerve cells
*chondrocytes
*erythrocytes |
| *the part of the cell cycle between one mitotic phase and the next, from the end of cytokinesis to the beginning of the next prophase
*period of growth of the cell, between divisions | interphase |
| what is RBE | relative biologic effectiveness- dose of radiation necessary to produce an effect vs. dose of a different type of radiation to produce same effect |
| what are the embryo/fetal radiation dose effects during 1st two weeks of pregnancy | no known effects |
| what are the embryo/fetal radiation dose effects during weeks 2 to 10 | congenital abnormalities, such as mental retardation or most commonly skeletal deformities |
| what are the embryo/fetal radiation dose effects during 2nd and 3rd trimesters | malignant childhood disease, most commonly leukemia |
| which two nitrogenous bases are purines | adenine and guanine |
| which two nitrogenous bases are pyrimidines | thymine and cytosine |
| a unit formed from a nitrogenous base, a five carbon sugar molecule, and a phosphate molecule | nucleotide |
