Unit 2- Rad Bio

what is number1?

lysosome

what is number 2?

centriole

what is 3?

mitochondrion

what is 4?

ribosomes

what is 5?

nucleus

what is 6?

smooth endoplasmic reticulum

what is 7?

golgi complex or golgi apparatus

what is 8?

cell membrane or plasma membrane

what is 9?

rough endoplasmic reticulum

function of smooth and rough endoplasmic reticulum

• “highways”

• communicates with outside of cell and helps with transportation

funciton of ribosomes

responsible for protein synthesis

function of mitochondria

• “power generator”/”power house” of the cell

• supply energy for cellular function

function of golgi apparatus (complex)

• transport hormones through the cell and into the blood stream

function of lysosome

• “garbage bags”

• breakdown large or unwanted molecules

function of centriole

• main organizing and regulator controls cell phases

function of cell membrane

• allows small molecules and water in and out of the cell

what will determine the degree and nature of the response

the atoms & molecules that radiation interacts with

radiation interacts at the ___ level

atomic

chain of development

atom→molecule→macromolecule→organelle→cell→tissue→organ→organ system→organism

__ interaction gives highest dose to techs, while __ gives highest dose to patients

compton; photoelectric

60% of the body is (most abundant)

hydrogen

25.7% of the body is

oxygen

the body is made primarily of

water (hydrogen & oxygen)

when radiation interacts with the body, it reacts with what element?

water

what are the 5 principal types of molecules in the body?

1. water

2. proteins

3. lipids-fats

4. carbs

5. nucleic acids

what is the simplest & most ABUDANT INORGANIC compound in the body?

water (does not contain carbon)

Roles of water in the human body (6)

1. Provides form and shape

2. Dissolves acids, bases, salts and chemical substances

3. Functions as a transport vehicle

4. Maintains body temp

5. Cushions vital organs

6. Lubricates digestive systems and joints

what are the building blocks of cells?

proteins

When are proteins formed?

when a sequence of amino acids connected by peptide bonds combine into long, chainlike molecular complexes (macromolecules)

Arrangement of amino acids determines what?

specific function & type

protein structure is

CHONT

what are proteins essential for?

• growth

• construction of new body tissues

• repair of injured or weakened tissues

what is the structural part of the cell membrane

lipids

lipids structure

CHO

Lipids are composed of

2 types of molecules:

1. glycerol

2. fatty acids

functions of lipids

• long-term stroage of energy

• insulate & protect

• support organs

• assist w/ growth & development

• lubricate joints

• assist in digestion

lipids make up what percent of cell

2%

carbs are also called

saccharides

carbs structure

CHO

carbs are

starches & sugars

function of carbs

• short-term energy storage

• cell shape & stability

simple carbs

monosaccharide

complex sugar

disaccharide

examples of monosaccharide

• glucose

• fructose

• galactose

examples of Disaccharides

• sucrose

• maltose

• lactose

2 types of nucleic acids

DNA & RNA

DNA (deoxyribonucleic acid)

• nucleus of the cell

• double stranded macromolecule

• command/control for function

what contains all the hereditary information of a cell?

DNA

what is the MOST radiosensitive target molecule

• DNA (has all info that a cell needs in order to function)

RNA (ribonucleic acid)

• cytoplasm of cell

• long, single-stranded chain of cells

what helps DNA translate information?

RNA

2 types of RNA

1. messenger RNA (mRNA)

2. transfer RNA (tRNA)

chromosomes

• Tiny rod-shaped bodies; only visible during Mitosis (cell division)

number of human somatic cells

46

number of human reproductive cells

23 pairs

__ composes chromosomes

DNA

__ compose DNA

genes

__ compose genes

bases

what have unique sequence of bases – info responsible for cell activity and development and all hereditary information

genes

mature cells are ___

highly specialized

cells need what 3 things?

1. source of energy

2. oxygen to break down food

3. water to transport substances

living contents of a cell surrounding by plasma membrane

Protoplasm

bulk of cell; structure, mass, & support

cytoplasm

center of cell; contains DNA

nucleus

__ is much more sensitive than cytoplasm

nucleus

what are the 2 most abundant atoms in the body?

hydrogen is #1, oxygen is #2

cell proliferation (division)

act of a single cell or group of cells reproducing & muliplying in number (cell division)

somatic cells go through what cell division

mitosis (46 chromosomes)

genetic (sperm & ova) go through what cell division

meiosis (2 pairs of 23 chromosomes)

somatic cells overview

• all cells except sperm & ova

• damage affects ONLY exposed individual

genetic cells overview

• sperm & ova ONLY

• damage can affect offspring

what are the 4 steps of cellular life? (interphase)

1. G1 phase

2. S phase

3. G2 phase

4. M phase

*period of growth between cell division

G1 phase

pre DNA; cell growth

S phase

DNA replication/synthesis (2 identical daughter molecules are formed)

G2 phase

post DNA synthesis/prepare for mitosis- production of RNA & proteins

M phase

mitosis & cytokinesis

what is the longest phase & period of growth?

interphase

least radiosensitive time (phase)

S

most radiosensitive time (division) & more susceptible to damage

mitosis (M phase)

Prophase (mitosis)

• Nucleus enlarges

• DNA more prominent/noticeable & takes structural form

• Centrioles migrate to opposite side of cell & form mitotic spindle

• Nuclear membrane disappears

metaphase (mitosis)

• Mitotic spindle forms between centrioles

• Chromosomes appear & line along the equator of the nucleus

• Critical time for damage

Mitosis can be stopped ONLY during what phase?

METAPHASE (chromosomes can be studied for radiation induced damage)

map of chromosomes

karotype

Anaphase (mitosis)

• Each chromosome splits at center

• The halves of the chromosomes migrate towards spindles

Telophase (mitosis)

• Chromosomes disappear into a mass of DNA

• cytokinesis occurs

cytokinesis

nuclear membrane and cytoplasm both divide into two

• Cell division is now complete

• two daughter cells appear as parent and contain exact genetic material

Meiosis

• cell division that reduces the chromosome number by half, creating four genetically unique haploid gametes (sperm and egg cells)

• reproduction!!!

instant death

• massive influx of energy into cells (disrupting form & structure of DNA)

• DNA then breaks up & cell proteins coagulate, killing the cell

apoptosis (interphase death)

• cells die during interphase w/o attempting division

mitotic (genetic) death

• Reproductive Death

• Permanent loss of ability to reproduce

• Cell continues to synthesize proteins, death then occurs

• Damage not able to be transmitted to future generations

mitotic delay (division delay)

• Cell doesn’t divide on time

• Disrupts ratio of those normally dividing and those not

• Cells recover from delay and proceed (more will be in mitosis at one time)

• Cause unknown

interference of function 2 types:

1. improper function= serious impairment

2. cease of function= cell death

reproductive death

• Doses of x-rays about 1 – 10Gy

• Permanent loss of ability to reproduce

• Cell continues to synthesize proteins

• Damage not able to be transmitted to future generations

interference of funcion

• affects the ability to divide, normal cell function and be impaired

• Repair enzymes can fix damage, cell continues to function

5 outcomes after irradiation

1. instant death

2. apoptosis (interphase death)

3. mitotic (genetic) death

4. mitotic delay (division delay)

5. interference function

molecular damage IS reversable!!

can be mended through repair enzymes & regeneration of cells & tissues

5 Factors that molecular repair depends on:

1. dose

2. dose rate

3. cell sensitivity

4. cell age

5. mitosis

sensitivity of a cell to radiation is determined by__

• maturity

• function role

immature cells are called

undifferentiated, precursor, or stem cells

law of bergonie & tribondeau

cells are most sensitive when they are immature, undifferentiated, & rapidly dividing