Rad Bio - Unit 2

composition of the body

the atoms & molecules that radiation interacts w/ will determine the degree & nature of the reponse

hydrogen

what is the most adubant atomic composition of the body?

water

what is the body mostly made of?

60%

what is the atomic composition of hydrogen in the body?

25.7%

what is the atomic composition of oxygen in the body?

10,7%

what is the atomic composition of carbon in the body?

2.4%

what is the atomic composition of nitrogen in the body?

water

what is the simplest & most abundant inorganic compound in the body?

80-85%

what is the molecular composition of water in the body?

provides form & shape

dissolves acids, bases, salts & chemical substances

functions as a transport vehicle

cushion vital organs

what are the roles water gives to the body?

15%

what is the molecular composition of protein in the body?

building blocks of cells

essential for growth, concentration of new body tissue, & repair of injured/weakened tissues

what are the roles of proteins in the body?

when a sequence of amino acids are connected by peptide bonds

combine into long, chainlike molecular complexes

how are proteins formed?

2%

what is the molecular composition of lipids/fats in the body?

structural part of the cell membrane (oxygen, hydrogen, carbon)

composed of 2 types of molecules

lipids/fats

long-term energy

insulate & protect

support organs

assit w/ gorwth & devleopment

lubricate joints

what are the functions of lipids/fats in the body?

glycerol & fatty acids

what two composed types of molecules make up lipids?

1%

what is the molecular composition of carbonhydrates in the body?

saccharides

what is another name for carbonhydrates?

structure → oxygen, carbon, hydrogen

starches & various sugars

carbonhyrdates

short-term energy storage

cell shape & stability

what are the carbonhydrates functions?

nucleus of the cell

double-stranded macromolecule

critical target molecule

DNA (deoxyribonucleic)

command/control molecule for cell function

contains ALL hereditary info. representing cell

what are the functions of DNA?

cytoplasm of the cell

long, single-stranded chain of cells

RNA (ribonucleic acid)

helps DNA translate info

what is the function of RNA?

messenger (mRNA) & transfer (tRNA)

what are the types of RNA?

tiny rod-shaped bodies

chromosomes

only during mitosis (cell division)

when are chromosomes visble?

46

how many stomatic cells are there?

23

how many human reproductive “germ” cells are there?

DNA

what composes chromosomes?

genes

what composes DNA?

bases

what composes genes?

a source of energy

oxygen to break down food

water to transport substances

what do cells need?

maintain homeostatsis

what is the function of a cell?

living contents of a cell surrounding by plasma membrane

protoplasm

bulk of the cell

mainly made up of water

structure, mass, support

cytoplasm

center of the cell

contains DNA
more sensitive to radiation

nucleus

the act of a single cell or group of cells reproducing & multiplying in numbers (cell division)

mitosis & meiosis

cell proliferation

stomatic cell division

46 chromosomes

mitosis

only the individual

what does raidation/damage to stomatic cells affect?

G1 phase, S phase, G2 phase

what are the subphases in Interphase of mitosis?

G1 phase

cell growth

pre-DNA synthesis

S phase

DNA replication

DNA synthesis

G2 phase

preparation for mitosis

post-DNA synthesis

prophase

nucleus enlarges

DNA becomes more prominent → takes structure

centrioles migrate to the opposite side of cell

begin to form mitosis spindle

metaphase

mitotic spindles forms between centrioles

chromosomes appear & line along equator of nucleus

critical time for damage

can be stopped to study chromosome damage

what can be done in the metaphase of mitosis?

karotype

map of chromsomes

each chromsome can be seen distinctly

anaphase

each chromsome split at center

halves of chromsomes migrate toward spindles

telophase

chrosomes disappear into a mass of DNA

cytokinesis

completion of cell division → two daughter calls appear as parent & conatin genetic material

cytokinesis

nuclear membrane & cytoplasm both divide into two

meiosis

genetic cells → sperm & ova ONLY

23 chromsomes

offspring

what does raidation/damage to genetic cells affect?

outcomes after irradiation

damage to DNA in nucleus can result in change w/ possible death or significant damage

improper function = serious impairment

cease to function = cell death

instant death

occurs w/ x-ray/gamma ray dose of 1,000 Gy w/in seconds or minutes

massive influx of energy = gross disruption of cell form & structure

reproductive death/mitotic (genetic) death

doses of x-ray about 1-10 Gy

permanent loss of ability to reproduce

cell continues to synthesis proteins

damage not able to be transmitted to future generations

apoptosis (interphase) death

cell die during the interphase w/out attempting division

doses of 1-serveral hundred Gy

occurs spontaneously in normal tissues & tumors

mitotic delay (division delay)

can be caused by as little as 0.01 Gy

cell doesn’t divide on time

disrupts ratio of those normally dividing & those not

cause unknown

inference of function

occurs from various doses

beside affecting ability to divide, normal cell function & be impaired

repair enzymes can fix damage

molecular repair

molecule damage is reversable

can be mended by repair enzymes

tissues & cells can regenerate

dose

dose rate

cell sensitivity

cell age

mitosis

what does molecule repair depend on?

tissues & organs

radiation ionizes atoms

effects appearance at whole body level

undifferentiated precursor or stem cells

what is another name for immature cells?

its maturity & functional role

what is the sensitivity of a cell depend on?

law of Bergonie & tribondeau

age & metabolic rate of tissue being irradiated determines the radiosensitivity of the tissue

radiosensitive

stems cells (in bone marrow) =

radioresistant

mature cells =

increase radiosensitivity

high proliferation rate & high gorwth rate =

immature

undifferentated

rapidly dividing

cells are most sensitive when

lymphocytes

what is the most radiosensitive cell?

divides rapidly

why are epitheial tissue & sperm cells radiosensitive?

blast

immature → still developing

not fully specialized

rapidly dividing/multiplying

cyte

mature → fully developed

specialized

NOT rapidly dividing/multiplying

lymphocytes

erthroblasts

intestinal epitheial cells

what are cells types that repsonse to high raidation?

spermatogonia

epitheial cells

osteoblast

fibroblast

what are cells types that repsonse to intermediate raidation?

muscle cells

adult nerve cells

what are cells types that repsonse to low raidation?

lymphoid tissue

bone marrow

what are tissue & organ types that repsonse to high raidation? (2-10Gy)

skin, breast, lung, GI tract, lens of the eyes, gorwing bone, liver, thyroid, gonads

what are tissue & organ types that repsonse to intermediate raidation? (10-50Gy)

kidney

muscle

brain

what are tissue & organ types that repsonse to low raidation?