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1

4 levels of organization of the body

Cell
Tissue
Organs
Systems

2

Basic structural unit of all organisms

Cell

3

Aggregate of similar cells and cell products forming a definite kind of structural material with a specific function in a multicellular organism

Tissue

4

Grouping of tissues into a distinct structure that performs a specialized task; ex: heart, lungs, stomach, etc.

Organs

5

Group of organs that work together and provide an organism with an advantage for survival, most complex organization in body
Ex: cardiovascular, respiratory, gastrointestinal, etc.

Systems

6

2 parts of cell composition

Protoplasm
Sodium and potassium

7

Chemical building material for all living things, 70-85% dissolved or suspended in water

Protoplasm

8

Protoplasm surrounding the cell nucleus where metabolic function takes place

Cytoplasm

9

Protoplasm inside the nucleus

Neoplasm

10

2 materials protoplasm consists of

Organic compounds
Inorganic materials

11

Compounds that contain carbon, hydrogen, and oxygen

Organic compounds

12

Compounds that don't contain carbon

Inorganic materials

13

Water helps to modulate when there's drastic ______ changes

Temperature

14

Balances osmotic pressure outside cell

Sodium

15

Balances osmotic pressure inside cell

Potassium

16

4 organic compounds

Protein
Carbohydrate (carb)
Nucleic acid
Lipid

17

Most elementary building blocks of cells that constitute about 15% of cell content, most plentiful of carbon-containing compounds

Protein

18

22 known organic compounds that are the building blocks of protein
Form protein when they combine into long, molecular chains held by peptide bonds

Amino acids

19

Covalent chemical bond linking two consecutive amino acid monomers along a peptide or protein chain

Peptide bonds

20

Molecular units that can chemically combine with other such units in a sequential manner resulting in polymers

Monomers

21

Process of reacting monomer molecules together in a chemical reaction to form polymer chains

Polymerization

22

Substance that has a molecular structure consisting chiefly or entirely of a large number of similar units bonded together

Polymers

23

Function as organic catalysts and control the cell's various physiologic activities that increase cellular activity that in turn causes biochemical reactions to occur more rapids to meed the needs of cells, proper cell functioning depends on these

Enzymes

24

Agents that affect the rate or speed of chemical reactions without being altered

Catalysts

25

Any of a large group of organic compounds occurring in foods and living tissues and including sugars, starch, and cellulose; contain hydrogen and oxygen and typically can be broken down to release energy in the body

Carbohydrates/saccharides

26

3 categories of carbohydrates

Monosaccharides
Disaccharides
Polysaccharides

27

Simple sugar, glucose

Monosaccharides

28

Two units of a simple sugar linked together

Disaccharides

29

Several or many molecules of sugar

Polysaccharides

30

2 types of nucleic acids

Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)

31

Contains all the information the cell needs to function, carries the genetic information necessary for cell respiration and regulates all cellular activity needed to direct protein synthesis
Composed of two long sugar-phosphate chains which twist around each other in a double-helix and are linked by pairs of nitrogenous organic bases

Deoxyribonucleic acid (DNA)

32

Single-stranded macromolecular structure that functions as a messenger between DNA and the ribosomes where synthesis occurs

Ribonucleic acid (RNA)

33

Structural components of cell membrane

Lipids/fats

34

3 functions of lipids

Storage of energy
Insulates and guards body
Assists with digestion

35

10 cell parts

Cell membrane
Cytoplasm
Endoplasmic reticulum (ER)
Ribosomes
Mitochondria
Lysosomes
Golgi complex
Nuclear membrane
Nucleolus
Nucleus

36

Functions as a barricade to protect cellular contents from their environment and controls the passage of water and other materials into and out of cell; semipermeable membrane for proteins, fats, and carbs

Cell membrane

37

2 metabolic functions

Catabolism
Anabolism

38

Break down organic material to produce energy

Catabolism

39

Building up cell

Anabolism

40

Extension of nucleus, vast irregular network of tubules and vesicles spreading and interconnecting in all directions throughout the cytoplasm and enables the cell to communicate and transfer food and molecules from one part of cell to another

Endoplasmic reticulum (ER)

41

2 types of ER

Rough
Smooth

42

ER with numerous ribosomes present

Rough ER

43

ER without ribosomes present

Smooth ER

44

Synthesizes proteins

Ribosomes

45

Powerhouse of cell with two membranes, inner membrane produces energy for cellular activity through oxidation

Mitochondria

46

Any chemical reaction in which an atom loses electrons

Oxidation

47

Sequence of reactions by which most living cells generate energy during the process of aerobic respiration

Krebs cycle

48

Breaks down unwanted/foreign materials that penetrate cell through microscopic channels or are drawn in by the cell membrane (ex: bacteria) and contain enzymes for digestion

Lysosomes

49

Extend from nucleus to cell membrane and consist of tubes and a tiny sac near nucleus, unites large carb molecules and combines them with proteins to form glycoprotein
When cell manufactures enzymes and hormones, this concentrates, packages, and transfers them through the cell membrane so they can exit the cell, enter the bloodstream, and be carried to the areas of the body where they're required

Golgi complex

50

Largest structure within nucleus where RNA is contained

Nucleolus

51

separation of nucleus from cytoplasm, permits selective passage of molecules from nucleus to cytoplasm and vice versa

Nuclear membrane

52

Heat of living cell separated from the other parts of the cell by a nuclear envelope/double-walled membrane
Spherical mass of neoplasm that contains the genetic material DNA and protein
Controls cell division and multiplication and the biochemical reactions that occur within the cell

Nucleus

53

Purines link with _______ only in certain specific combination

Pyrimidines

54

2 purines that link with 2 pyrimidines of DNA in certain specific combination

Adenine (A) - thymine (T)
Guanine (G) - cytosine (C)

55

Tiny rod-shaped bodies that carry genes visible during cell division joined by two arms at centromere

Chromosome

56

Region of a chromosome to which the microtubules of the spindle attach during cell division

Centromere

57

2 types of cells

Germ cells
Somatic cells

58

Reproductive cells

Germ cells

59

Mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote; have 23 chromosomes

Gametes (1n)

60

Female and male germ cells

Female: oocytes
Male: spermatozoa

61

Diploid cell resulting from the fusion of two haploid gametes

Zygotes (2n)

62

Any cell of a living organism other than the reproductive cells; diploid, 46 chromosomes

Somatic cells

63

Type of somatic cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth
Division usually no longer than one hour, when cell is most sensitive

Mitosis

64

Type of germ cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes

Meiosis

65

4 phases of mitosis

Prophase
Metaphase
Anaphase
Telophase

66

Each of the two threadlike strands into which a chromosome divides longitudinally during cell division held together by a centromere

Chromatid

67

Missing, extra, or irregular portion of chromosomal DNA before and after DNA synthesis

Before: chromosome aberration
After: chromatid aberration

68

First stage of cell division
Nucleus and chromosomes enlarge, DNA complex coils up more tightly, DNA begins to take structural form, nuclear membrane disappears, and the centrioles migrate to opposite sides of the cell and begin to regulate the formation of the mitotic spindle

Prophase

69

Chromosomes line up and form equilateral plate along middle of cell, nucleus disappears, and centromeres start duplicating and each chromatid attaches itself individually to the spindle

Metaphase

70

Chromatids repel each other and migrate to opposite ends of cell
Microtubules start shortening, pulling chromatids to respected centrioles
Cell membrane divides

Anaphase

71

Chromatids lose appearance and form strands, cytoplasm splits and cell membranes begin to form, and nuclear membrane and nucleolus reappear
Results in two identical daughter cells with same number of chromosomes

Telophase

72

Resting phase
When DNA's synthesized, doubles amount of DNA

Interphase

73

5 phases of cell cycle

Mitosis
G1
Synthesis (S)
G2
G0/resting

74

Pre-DNA synthesis phase after telophase

G1

75

DNA replication can take up to 15 hours, most radioresistant

Synthesis (S)

76

DNA not replicating, 1-5 hours

G2

77

Accounts for cells that show no evidence of progressing through cell cycle

G0/resting

78

Cells in G0 that can be pulled in cell cycle if needed for reproduction

Quiescent cell

79

Adding or removing an electron to alter cell which becomes charged

Ionization

80

Biologic damage occurs as a result of ionization of atoms on essential molecules such as DNA, RNA, proteins, and enzymes that may potentially cause these molecules to become inactive or functionally altered
High LET like alpha particles and neutrons

Direct interaction

81

2 interactions with living cells

Direct
Indirect

82

Effects produced by free radicals that are created by the interaction of radiation with water molecules because 85% of cell is water
Low LET
Interaction of radiation with water results in the formation of an ion pair, hydrogen, and hydroxyl ion (H+ or OH-) and two free radicals, a hydrogen radical and a hydroxyl radical (H* and OH*)

Indirect interaction

83

Configuration with one or more atoms having an unpaired electron but no net electrical charge, highly interactive because the unpaired electron will pair up with another electron even if it has to break a chemical bond

Free radical

84

The amount of energy deposited by radiation per unit length of travel, expressed in keV per micron (keV/um)

Linear energy transfer (LET)

85

2 types of LET

High LET
Low LET

86

Particles that possess substantial mass and charge, can produce dense ionization along its path and is therefore much more likely to interact significantly with biologic tissue
Loses energy more rapidly because they produce more ionization per unit distance travelled

High LET

87

Electromagnetic radiation causes damage to biologic tissue through indirect action or directly induce single-strand breaks in DNA
Repair enzymes can usually reverse the damage
Sparsely ionizing, low mass and no charge

Low LET

88

Describes the relative capabilities of radiation with different LETs to produce a particular biologic reaction

Relative biologic effectiveness (RBE)

89

2 units of RBE

Rem
Sievert (Sv)

90

Rad x quality factor (QF)

Rem

91

RBE formula

Orthovoltage or dose in Gy from 250 keV/dose in Gy from another radiation source delivered under the same conditions that produce the same biologic effect

92

LET of radiation

Quality factor (QF)

93

1 Sv = ___ rem
1 rem = ___ Sv
1 rem = ___ mSv

1 Sv = 100 rem
1 rem =0.01 Sv
1 rem = 10 mSv

94

Max RBE

Alpha particles = 3

95

2 target theories

Single
Multiple

96

Only one target in the cell that's associated with cell death and a single hit on this target's, usually DNA, adequate to inactivate the target (viruses and some bacteria); helps determine population survival with high LET

Single target theory

97

Over one target per cell and a single hit to any of these targets is required for cell death
Not all targets are hit, some are killed while others are damaged by low doses (mammalian cells)
Determines cell population survival with low LET, how well cell repairs

Multiple target theory

98

4 ways RT damages DNA from least to most severe

Base damage
Single strand break/point mutation
Double strand mutation
Cross-linking

99

Direct action, change in nucleic acid results in loss of general information

Base damage

100

Energy from ionizing radiation can rupture one of DNAs chemical bonds and possible sever one of the sugar-phosphate chain side rails/strands, can result in a gene abnormality
Commonly occurs with low LET radiation but repair enzymes are often capable of reversing this damage

Single strand break/point mutation

101

When high LET radiation interacts with DNA, the interactions may be so closely spaced that both strands of the DNA chain are broken
Can heal or cross-link (cell damage)

Double strand break/mutation

102

Chemical unions created between atoms by the single sharing of one or more pairs of electrons
Most severe, chan be interstrand or with another strand
Can affect cell, pass on to daughter, or have no effect

Cross-linking

103

5 chromosome/chromatid structural changes from RT

Acentric/dicentric fragment
Ring formation
Chromosome stickiness
Translocation
Inversion

104

Chromosome with none or two centromeres, loss of information because arms of chromosome break off

None: acentric fragment
Two: dicentric fragment

105

Radical figures in which chromosomes aren't obviously broken, but are linked by a tiny filament
Induced in mid to late G2, metaphase and anaphase
Result from recombinations occurring at nonrandom chromosome regions
Radiation changes protein structure in chromosome

Chromosome stickiness

106

Rearrangement of parts between nonhomologous chromosomes
Two complete chromosomes form
Affects germ cells because of meiosis

Translocation

107

Segment of a chromosome is reversed end to end
Deletion results in information loss, greater effect on germ cells
Occur when a single chromosome undergoes breakage and rearrangement within itself

Inversion

108

Chromosomes rejoin when broken, occurs 95% of time in human cells
No loss of general information

Restitution

109

Broken arms join to form a ring, while the remaining fragments join but are left without a centromere (acentric fragment)
Loss of general information and will replicate; one daughter cell has too much information and the other doesn't have enough

Ring formation

110

2 types of inversion

Paracentric
Pericentric

111

3 affects chromosome structural changes from RT can have

Fatal
Pass on mutation/change to daughter cell
No affect

112

What does the consequence of translocation and inversion depend on?

Number of bases

113

DNA effects occur during _______, chromosome effects during _______ and _______

Interphase
Meta- and anaphase

114

2 things chromosome damage is affected by

Dose rate
LET

115

Chromosome damage _______ with dose rate and LET

Increases

116

Low LET produces _______ and _______, high LET causes _______ amounts of damage

Deletions and inversions
High

117

2 groups cell cycle studies have been done on

Asynchronous
Synchronous

118

Cells in all phases of cell cycle, useful for in vivo studies

Asynchronous

119

Cells grouped in specific stages of cell cycle useful for in vitro studies

Synchronous

120

Drug that syncs cells to help determine reaction to radiation dose

Hydroxurea

121

Delay cell from division; mitotic index altered because of exposure to ionizing radiation and division is delayed, leading to a false surge in division once it resumes

Division delay

122

During radiation if cell is in _______, it will complete cycle; if in _______, division delay occurs

Mitosis, G2

123

How does RT work in the treatment of cancer (rad bio effect)

First dose of radiation syncs cells and makes them more sensitive

124

Cell death before cell divides, can happen in nondividing or rapidly dividing cells
Programmed cell death usually from chemical change

Interphase death
Apoptosis
Non-mitotic death
Non-division death

125

3 things that can happen to irradiated cell

Division delay
Interphase death
Reproductive failure

126

Ratio of the number of cells in mitosis at a given time to total number of cells in the population

Mitotic index

127

When a percent of the cell population in mitosis is artificially increased due to division delay

Mitotic overshoot

128

Interphase death dose for lymphocytes and parotids

Lymphocytes = 0.5 Gy
Parotids = 9 Gy

129

Inability of cell to undergo repeated division after irradiation

Reproductive failure

130

Cells that are alive but can't divide

Nonsurvivors/dead cells

131

Radiosensitivity of early and late G1

Early: radioresistant
Late: moderately sensitive

132

Radiosensitivity of early and late S

Early: moderately sensitive
Late: most radioresistant

133

Radiosensitivity of early and late G2

Early: second most resistant
Late: more sensitive

134

Radiosensitivity of early and later mitosis

Most sensitive

135

Graphically represents radiation effects

Cell survival curves

136

Dose of radiation, amount of radiation exposure to cell

X-axis

137

Percent of surviving cells, non-logarithmic
Higher up = more survival

Y-axis

138

Dose of radiation that's required to destroy all except 37% of cell population
Degrees of steepness/reciprocal of slope
Final/terminal portion of curve that starts approximating straight line; helps describe radiosensitivity
1/slope = 1/(rise/run)

Do/D37

139

Cellular damage proportional to radiation dose
Measures width (not shape) of shoulder region of curve; measure of cell's population to accumulate and recover from SLD
Dose at which extrapolation of terminal/lower portion of curve intersect dose axis
Measures shoulder width above 100%

Dq
Quasithreshold dose
Threshold dose

140

Number of key targets in the cells that must be struck by the radiation to produce the response the curve demonstrates, 2-10 for mammalian cells

N/extrapolation number

141

Dose range of radiation that kills mammalian cells

1-2 Gy (daily fractions)

142

Initial exponential slope before approximated straight line, shoulder

1 Do

143

Do increase = ______ survival

Increases

144

Shallow curve/broader shoulder = _______ survival

More

145

Steep curve/straighter line ______ Do and more cells die

Decreases

146

2 things that can happen to Dq

No change; if Dq same for both exposures, cells completely repaired SLD because not enough dose, too much time between dose, environment, etc.
Gets smaller/shallower because not as much repair/cells dying

147

Decrease Dq = _______ repair of SLD

Decrease

148

Value obtained by extrapolating the exponential portion of the curve to the vertical line
Bottom of curve never reaches x-axis because we never kill all cells, some survive

N number
Definition
Target number

149

High LET = _______ fractions

Decrease

150

Increase oxygen = _______ damage/less repair

Increase

151

With oxygen and high LET = _______ effect, low LET with oxygen = _______ effect

No great
Drastic

152

Damage that can be repaired by cell, passed on; has to be determined by two radiation exposures
Same shoulders = repair

Sublethal damage (SLD)

153

Type of repairable damage that can be observed after a single radiation dose dependent on cells environment
Only works for sparsely ionizing radiation (low LET)

Potentially lethal damage (PLD)

154

Oxygen = _______ environment, hypoxic = _______ environment

Good, poor

155

Does a good or poor environment help cells repair?

Poor environment after radiation exposure slows down division process and gives cells more time to repair