ENVI HEALTH Flashcards
1
Q
Several membrane barriers
A
If the chemical has not been injected intravenously, it will cross ____
2
Q
Phospholipid bilayer
A
all membranes are consist ___
3
Q
Hydrophilic (polar) ; hydrophobic (nonpolar)
A
Phospholipid bilayer has ____ outer boundary and _____ interior
4
Q
rigid
A
polar portions of the phospholipid molecules maintain a relatively ___ outer structure
5
Q
Fluidity
A
nonpolar interiors are arranged in a formation that gives ____ of the membrane structure.
6
Q
Proteins
A
____ that are embedded throughout the phospholipid bilayer have specific functions in the crossing of a chemical.
7
Q
Passive and facilitated diffusion, and active transport
A
Chemicals can cross membranes by three principal mechanisms which are ___
8
Q
Passive transfer
A
does not involve the participation of any membrane proteins
9
Q
factors that determine the rate of passive diffusion
A
The difference between the concentrations of the chemical on the two outer sides of the membrane.
10
Q
factors that determine the rate of passive diffusion
A
The ease with which a molecule of the chemical can move through the lipophilic interior of the membrane
11
Q
Lipid solubility, molecular size, degree of ionization
A
Three major factors affect ease of passage
12
Q
Lipid solubility
A
expressed by its partition coefficient
13
Q
Partition coefficient
A
concentration of the chemical in an organic phase divided by its concentration in water at equilibrium between the two phases.
14
Q
Chloroform, hexane or heptane, or ocatanol
A
The organic phase is often ____
15
Q
Partition coefficient
A
determined by shaking the chemical with water and the organic solvent and measuring the concentration of the chemical in each phase at equilibrium.
16
Q
decreases
A
As the size of the molecule increases, with lipophilicity remaining approximately constant, rate of movement across the membrane _____
17
Q
Fictional resistance
A
The transfer of larger molecules is slowed
18
Q
Very small molecules
A
may move across the membrane more rapidly than would be predicted based on their partition coefficients alone.
19
Q
Small molecules
A
likely to be more degree of ionization water-soluble than their larger homologs.
20
Q
Small molecules
A
may be also able to move through membrane pores.
21
Q
pores
A
features of all membranes.
22
Q
4x10-4 µm
A
Cell membranes will not allow passage of water-soluble molecules larger than about ___ in diameter
23
Q
30x10-4 µm
A
Blood capillary walls allow passage of water-soluble molecules up to about ___ in diameter
24
Q
electrolytes
A
are ionized at the pH values of body fluids.
25
large
The ionized electrolytes are generally too ____ to pass through aqueous membrane pores
26
nonionized forms
Only the ____ of most electrolytes can cross membranes, except for some very small, ionized molecules.
27
Ionized electrolytes
very hydrophilic that they cannot be transferred by passive diffusion.
28
Acids and Bases
are ionizable, and they have a pH value related to the dissociation constant.
29
degree of ionization
______ in body fluids depends on the pH of the medium and on the pH acid or base.
30
strong acids
Acids having a large pKa or higher pH (weak acids) are not as fully ionized as ______ .
31
weak bases
Bases having a large pKa or higher pH (strong bases) are more fully ionized than _____
32
Weak acids and bases
largely nonionized at the intestinal surface pH of 5.3, were readily absorbed by the membrane
33
Not readily absorbed
Strong acids (pKa < 3), and ___ strong bases (pKa > 7)
34
Facilitated diffusion
requires the participation of a carrier protein molecule.
35
Carrier proteins
embedded in the membrane lipid bilayer.
36
Facilitated diffusion
can also be inhibited selectively or competitively by chemical agents that binds on the carrier protein because of the similarity on their chemical structures.
37
Relatively faster
The rate of the facilitated diffusion is ____ than of passive diffusion
38
Selectively bind
For the facilitated diffusion to work, the diffusing molecule must be able to ___ to the carrier protein which requires very specific structure or conformation.
39
Facilitated mechanism
responsible for the transport of essential nutrients across membrane barriers.
40
Example of facilitated mechanism
transport of sugars and amino acids into red blood cells and into the central nervous system
41
Active transport
process by which molecules can cross cell membranes.
42
Active transport
requires a carrier molecule and a controlled energy input.
43
Active transport
The mechanism maintains transport between concentration difference of the outer and inner cell membranes.
44
Adenosine triphosphate (ATP)
source of the energy required to maintain this concentration difference.
45
Active transport
vital to the conservation and regulation of essential nutrient in a body.
46
Excretion
important functions of the kidney and the liver which include the ____ of toxic chemicals and transforming the chemical into their metabolites.
47
Kidney, liver, placenta, intestinal wall
Different sites for active transport
48
kidney
processing water-soluble toxicants and secretion into urine
49
Liver
processing the fat-soluble toxicants and elimination into the bile
50
Human body
can be exposed to a variety of toxicants
51
air, soil, water, or food
Environmental media
52
Toxicological response
just simply being exposed to these hazardous chemicals does not necessarily translate into a ____
53
Defense mechanisms and membrane proteins
The mammalian body has several inherent ____ and ____ which tend to prevent the entry or absorption and distribution of these toxicants once an exposure event has occurred
54
Toxicant and body ’s barriers and defense mechanisms
interactions between the ___and the _____ will have an effect on toxicant movement in the body, and ultimately modulate the rate and extent of toxicant absorption and distribution to the target tissue.
55
skin
the largest organ in the human body, and one of its primary functions as a physical barrier to absorption of toxicants.
56
Respiratory and gastrointestinal tract (GIT)
The other major routes of toxicant entry into the body are through the ____ and ____ which can be seen to offer less resistance to toxicant absorption than the skin.
57
respiratory
Offers the most rapid route
58
Dermal
Least rapid
59
Membrane thickness
Difference in rapid entry is due to ___
60
Amount and saturability
overall entry depends on both the ___ present and the ___ of the transport process involved
61
Bulk transfer (bloodstream), and diffusional transfer (molecule by molecule over short distance)
Once the toxicant has been absorbed, the toxicant molecules can move around the body in two ways
62
diffusional characteristics
what distinguishes one toxicant pharmacokinetically from another is its ____
63
Diffusional characteristics
its ability to cross nonaqueous diffusional barriers (e.g., cell membranes) from an aqueous compartment.
64
phospholipids
Cell membrane consists primarily of ___
65
Fluid like
Phospholipids in the membrane are ___ they can move easily
66
Semi-permeable membrane
Will allow passage through the membrane but need to control what gets in or out
67
Semi-permeable
Membrane is ____
68
Small lipids
can slip directly through the phospholipid cell membrane.
69
diffusion
Passive transport of small molecules-high to low concentration
70
Facilitated diffusion
Passive transport of larger molecules
71
Facilitated diffusion
Through a protein channel
72
Facilitated diffusion
High to low concentration gradient
73
Active transport
Diffusion against the concentration gradient
74
Active transport
Low to high
75
Active transport
Uses a protein channel (pump)
76
Active transport
Requires ATP energy
77
Passive transport
Movement from high to low concentration
78
concentration gradient
Each substance diffuses down its own ____, independent of concentration gradients of other substances
79
osmosis
Diffusion of water
80
HIGH to LOW
Water goes from _____ concentration
81
Passive transport
osmosis
82
osmosis
No energy needed (does not require ATP)
83
High to low
Simple diffusion – which way will lipid move?
84
High to low
Facilitated diffusion – which way will sugar move?
85
Semi-permeable
Membrane needs to be ___s
86
Specific channels
Allow specific material in and out
87
Active transport
Needs atp
88
pump
Membrane proteins act as a ____ for specific molecules
89
Active transport
Cells may need molecules to move against concentration situation protein pump
90
Vesicles and vacuoles
Moving large molecules into & out of cell
91
endocytosis
Moving into cells
92
Phagocytosis
Cell eating
93
pinocytosis
Cell drinking
94
Exocytosis
Moving out
95
Membrane
collage of different proteins embedded in the fluid matrix of the lipid bilayer
96
Isotonic solution
When the concentration of water is the same inside and outside cell
97
Hypotonic solution
When there is a higher concentration of water outside cell, so water moves into cell
98
Hypertonic solution
when there is a higher concentration of water inside cell, so water moves out of cell
99
Balanced condition
No difference between cell and environment
100
Isotonic solution
Balanced conditions
101
Blood
Example of balance conditions
102
Balanced conditions
water flows across membrane equally,
103
Balanced conditions
volume of cell doesn’t change
104
Hypotonic solution
A cell in freshwater
105
paramecium
Example of hypotonic solution
106
Gains water, wells and can burst
Problem of hypotonic solution
107
Contractile vacuole – pumps water out of cells
Solution of hypotonic solution
108
A cell in saltwater
Example shellfish
109
Saltwater (hypertonic solution)
Lose water
110
Problem in hypertonic solution (saltwater)
Plasmolysis in plants
111
Problem in hypertonic solution (saltwater)
Shrinking cells
112
Solution in hypertonic solution (saltwater)
Take up water
113
Passive transport
Also called simple diffusion
114
Passive transport
movement from High to low concentration. No energy is used
115
Active transport
movement from low to high
116
Active transport
Needs energy
117
Active transport
Opposite of simple diffusion
118
Active transport
Cells may need molecules to move against concentration difference
119
Active transport
need to pump “uphill”
120
pinocytosis
cell drinking-engulfing small particles.
121
phagocytosis
Cell engulfing- ex Lysosomes fuse with a bacteria for digestion
122
Cyclosis
Movement of the cytoplasm
123
Membrane carbohydrates
Play a key role in cell-cell recognition
124
Cell – cell recognition
ability of a cell to distinguish neighboring cells from another
125
Cell – cell recognition
important in organ & tissue development
126
Risk assessment
probability that a health effect will occur after an individual has been exposed to a specified amount of a hazard
127
Risk assessment
process of gathering all available information on the toxic effects of a chemical and evaluating it to determine the possible risks associated with exposure
128
2. Hazard evaluation or Dose-Response Assessment
process of gathering and evaluating the information can be divided into:
129
Hazard identification
first step in risk assessment consists in collecting data from different sources to determine whether a substance is toxic.
130
Hazard identification
involves gathering and examining data from toxicological and epidemiological studies
131
o What is its size?
Information collected and considered when performing a risk assessment are:
132
· Other factors to consider when determining potential exposures to toxic substances include diet, lifestyle choices, and occupation.
Information collected and considered when performing a risk assessment are:
133
Hazard evaluation
If the hazard identification process produces evidence of a hazard, then a ___ is performed
134
Hazard Evaluation and Dose response assessment
The purpose of this step is to calculate, if possible, the dose at which a harmful effect will occur.
135
Exposure assessment
performed to identify the affected population and, if possible, calculate the amount, frequency, length of time, and route of exposure.
136
General information for each chemical, sources, exposure pathways and environmental fate, measured or estimated concentrations, Exposed human populations, integrated exposure analysis
Factors to consider when performing an exposure assessment include:
137
General information for each chemical
Identification of molecular formula and structure (how the chemical looks and is made) and other identifying characteristics
138
General information for each chemical
Chemical and physical properties
139
sources
Characterization of production and distribution, uses, disposal, summary of environmental releases
140
exposure pathways and environmental fate
Transport and transformation, Identification of principal pathways of exposure, Predicting environmental distribution
141
Measured or estimated concentrations
Uses of measurements and estimation of environmental concentrations
142
Exposed human populations
Size and characteristics, Location, Habits
143
Integrated exposure analysis
Calculation of exposure includes identification of the exposed population and identification of pathways of exposure
144
Risk characterization
last and final step in the risk assessment process is putting all of the information gathered from the other steps together to determine the actual risk of exposure to a specific toxic substance.
145
Risk characterization
This step relies on the expertise of the assessor in analyzing the information.
146
Risk management
Based on information obtained from the risk assessment, decisions are made about the best way to address environmental contamination and exposure.
147
Risk manager
also includes an evaluation of social, legal, economic, and policy issues to determine the best approach to address an exposure issue.
148
Irritation or exacerbation
state of inflammation or painful reaction to allergy or cell-lining damage
149
Irritant
A stimulus or agent which induces the state of irritation is an _____
150
Irritants
typically thought of as chemical agents (for example phenol and capsaicin)
151
Irritants
mechanical, thermal (heat), and radiative stimuli (for example ultraviolet light or ionising radiations) can also be ___
152
allergic response
In higher organisms, an ___ may be the cause of irritation
153
Allergen
defined distinctly from an irritant.
154
Allergy
requires a specific interaction with the immune system and is thus dependent on the (possibly unique) sensitivity of the organism involved.
155
Irritant
acts in a non-specific manner.
156
Pine processionary caterpillar, Thaumetopoea pityocampa
a serious pest causing dermatitis epidemics and eye problems
157
Urticating hairs of caterpillars of the gypsy moth
cause dermatitis and hives
158
Blister beetles (Epicauta spp.)
secrete a substance that causes blistering on contact with human skin
159
Eye irritation
Emission of various particulate and volatile substances has been suggested as specific causes.
160
Sick Building Syndrome
irritation to the eyes, skin, and upper airways, headache and fatigue is related to ____
161
eye
source of chronic irritation
162
Sjögren's syndrome
Disorders like ____ one does not make tears, can cause a dry eye sensation which feels very unpleasant
163
Sjögren's syndrome
difficult to treat and is lifelong
164
Artificial tears and drug called Restasis
What can help Sjogren’s syndrome?
165
Blepharitis
dryness and itching on the upper eyelids
166
Blepharitis
often seen in young people and can lead to reddish dry eye and scaly eyebrows
167
chronic bronchitis
Individuals who smoke or are exposed to smog or other airborne pollutants can develop a condition known as ____
168
chronic bronchitis
there is constant irritation of the breathing tubes (trachea) and the small airways
169
chronic bronchitis
The constant irritation results in excess production of mucus which makes breathing difficult.
170
chronic bronchitis
Frequently, these individuals wake up in the morning with copious amounts of foul smelling mucus and a cough which lasts all day.
171
Wheeze and heavy phlegm
Common findings in chronic bronchitis
172
chronic bronchitis
a lifelong disorder and there is no cure
173
chronic bronchitis
Eventually most people develop recurrent pneumonia, lack any type of endurance, and are unable to work productively
174
stop smoking
One of the ways to avoid chronic bronchitis is to ____
175
Eczema
simply means a dry skin which is itchy.
176
Eczema
condition usually starts at an early age and continues throughout life.
177
itchy dry skin.
major complaint of people who suffer from eczema is an ___
178
Skin rash
Sometimes, the itching will be associated with a ___
179
Eczema
affected areas are always dry, scaly, reddish and may ooze sometimes.
180
Eczema
cannot be cured, but its symptoms can be controlled
181
allergies
There are also many individuals who have ____ to a whole host of substances like nuts, hair, dander, plants and fabrics
182
Poisonous plants
can be found in woodlands and areas of dense vegetation, and can cause severe itching and irritation on the skin.
183
Poison sumac, poison ivy, poison oak
The most common poisonous plants
184
Poisonous plant (Poison sumac, poison ivy, poison oak)
can effect the skin upon contact, releasing chemicals onto the skin that burn and irritate it.
185
acne
an inflammatory skin irritation that produces pustules, papules, cysts, whiteheads and blackheads on the skin.
186
over-scrubbing
Accompanying these inflammations are areas of redness and peeling that occurs from ____ of the skin.
187
Gastritis
basically inflammation of the stomach wall lining and has many causes.
188
Gastritis
Smoking, excess alcohol consumption and use of non steroidal anti inflammatory drugs account for the majority of causes of ____.
189
Gastritis
In some cases, ____ may develop after surgery, a major burn, infection or emotional stress radiate
190
sharp abdominal pain which may radiate to the back
Symptoms of gastritis
191
may be associated with nausea, vomiting, abdominal bloating and a lack of appetite
Symptoms of gastritis
192
result in loss of blood on the stools.
Severe gastritis
193
antacids or acid neutralizing drugs, antibiotics, avoiding spicy food and alcohol.
Treatment for gastritis
194
Enzymes
proteins that serve as biological catalysts for reactions in all living organisms
195
Enzymes
increase the rate of a reaction (106 to 1012 times faster), but are unchanged themselves.
196
Enzymes
very specific – catalyzes a certain reaction or type of reaction only.
197
“ase”
The names of most enzymes end with the suffix ____
198
Peptidase, lipase, hydrolase
Example of enzymes
199
Cofactor
metal ion or an organic molecule needed for an enzyme-catalyzed reaction to occur
200
NAD+
the cofactor (coenzyme) that oxidizes lactate to pyruvate with the aid of the enzymelactate dehydrogenase:
201
enzyme
contains an active site that binds the substrate, forming an enzyme-substrate complex
202
catalyst
Once the reaction has occurred, the ___ released the product(s).
203
Lock and key model; induced-fit model
Two models have been proposed to explain the specificity of a substrate for an enzyme’s active site.
204
Lock and key model
states that the active site is a rigid cavity; to react, the substrate must exactly match the shape of the active site.
205
Induced-fit model
states that the active site has a flexible shape, which can adjust to fit a variety of substrate shapes.
206
inhibitor
bonds to the enzyme and alters or destroys the enzyme’s activity.
207
reversible or irreversible
inhibition can be_____
208
noncompetitive inhibitor
bonds to the enzyme, but not to the active site
209
Competitive inhibitor
has a shape and structure similar to the substrate, so it competes with the substrate for binding to the active site
210
Zymogens (proenzymes)
an inactive form of an enzyme that can be converted to the active form when needed.
211
higher amounts
Certain enzymes are present in ___ in particular cells.
212
Heart attack
Creatine phosphokinase
213
Liver or bone disease
Alkaline phosphatase
214
Prostate cancer
Acid phosphatase
215
Penicillin
inhibits the enzyme that forms cell walls of bacteria, destroying the bacterium
216
ACE (angiotensin-converting enzyme)
causes blood vessels to narrow, increasing blood pressure
217
ACE inhibitors
given to those with high blood pressure to prevent ACE’s synthesis from it’s zymogen.
218
HIV protease
an essential enzyme that allows the virus to make copies of itself.
219
HIV protease inhibitors
interfere with this copying, decreasing the virus population in the patient.
220
Lipid peroxidation
a metabolic process that causes oxidative deterioration of lipids by reactive oxygen species.
221
Lipid peroxidation
This process can degrade the lipids within the cell membrane leading to cell damage and eventually, cell death.
222
Lipids
heterogeneous class of naturally occurring organic compounds classified together on the basis of common solubility properties
223
Lipids
insoluble in water, but soluble in aprotic organic solvents including diethyl ether, chloroform, methylene chloride, and acetone
224
Lipids
Amphiphatic in nature
225
Open chain forms, cyclic forms
Lipids include:
226
Open chain forms
• fatty acids, triacylglycerols, sphingolipids, phosphoacylglycerols, glycolipids
227
cyclic forms
cholesterol, steroid hormones, and bile acids
228
Fatty acids
unbranched-chain carboxylic acid, most commonly of 12 - 20 carbons
229
Fatty acids
derived from hydrolysis of animal fats, vegetable oils, or phosphodiacylglycerols of biological membranes
230
Length
____ of fatty acid plays a role in its chemical character
231
unsaturated
Fatty acids that contain C=C are ____
232
saturated
If fatty acids contain only C-C bonds, they are ____
233
Cis isomer
In most unsaturated fatty acids, the ____ predominates; the trans isomer is rare
234
Trans
In most unsaturated fatty acids, the ____ is rare
235
Unsaturated fatty acids
have lower melting points than their saturated counterparts
236
Unsaturation
the greater the degree of ___, the lower the melting point
237
Triacylglycerol (triglyceride):
ester of glycerol with three fatty acids
238
Natural soaps
are prepared by boiling triglycerides (animal fats or vegetable oils) with NaOH, in a reaction called saponification (Latin, sapo, soap)
239
phosphatidic acid
When one alcohol group of glycerol is esterified by a phosphoric acid rather than by a carboxylic acid, ___ if produced
240
Phosphoacylglycerols (phosphoglycerides)
second most abundant group of naturally occurring lipids, and they are found in plant and animal membranes
241
waxes
complex mixture of esters of long-chain carboxylic acids and alcohols
242
waxes
Found as protective coatings for plants and animals
243
Sphingolipids
Contain sphingosine, a long-chain amino alcohol sphingosine
244
Sphingolipids
Found in plants and animals
245
Sphingolipids
Abundant in nervous system
246
Sphingolipids
Bares structural similarity to phospholipids
247
Glycolipid
a compound in which a carbohydrate is bound to an -OH of the lipid
248
Glucose or galactose
In most cases, sugar is either _____
249
Ceramides
many glycolipids are derived from ____
250
gangliosides
Glycolipids with complex carbohydrate moiety that contains more than 3 sugars are known as ____
251
Steroids
group of lipids that have fused-ring structure of 3 six-membered rings, and 1 five-membered ring.
252
Androgens
male sex hormones
253
Androgens
synthesized in the testes
254
Androgens
responsible for the development of male secondary sex characteristics
255
Androgens
Testosterone
256
Estrogens
female sex hormones
257
Estrogens
synthesized in the ovaries
258
Estrogens
responsible for the development of female secondary sex characteristics and control of the menstrual cycle
259
Cholesterol
The steroid of most interest in our discussion of biological membranes is ____
260
Cell membrane (plasma membrane)
Every cell has a ____
261
Eukaryotic cells
have membrane-enclosed organelles
262
Lipid components
Molecular basis of membrane structure is in ___
263
Polar head
_____ groups are in contact with the aqueous environment
264
nonpolar tails
____ are buried within bilayer
265
Hydrophobic interactions
the major force driving the formation of lipid bilayers is _____
266
Rigid; fluid
the arrangement of hydrocarbon tails in the interior can be ___ (if rich in saturated fatty acids) or ____ (if rich in unsaturated fatty acids)
267
charged groups
The polar surface of the bilayer contains ____
268
hydrophobic tails
lie in the interior of the bilayer
269
highly reactive free radical species
Causes of lipid peroxidation
270
Free radical chain reactions
occurs during lipid peroxidation as once a free radical is produced, it can react with another stable species to produce another free radical.
271
products of lipid peroxidation
useful indicators of oxidative stress in tissues and have been linked to the progression of cancer.
272
Glucose, vegetable oils, iron, pollution, chemicals, low oxidants
Top oxidizers
273
Lipid peroxidation
refers to the oxidative degradation of lipids.
274
Lipid peroxidation
process whereby free radicals "steal" electrons from the lipids in cell membranes, resulting in cell damage.
275
free radical chain reaction
This process proceeds by a ____ mechanism. It most often affects polyunsaturated fatty acids(PUFA).
276
Mutagenic and carcinogenic
end products of lipid peroxidation may be ____ and ___
277
hydroperoxides (LOOH), aldehydes such as malondialdehyde (MDA), 4-hydroxynonenal (4-HNE)
Products of lipid peroxidation
278
LOOH
primary products of lipid peroxidation produced in the propagation step.
279
LOOH
After formation, ____ can be reduced leading to inhibition of peroxidative damage or peroxidative damage induction.
280
malondialdehyde (MDA)
most mutagenic product of lipid peroxidation and is commonly used as a biomarker for oxidative deterioration in omega-3 and omega-6 fatty acids.
281
4-hydroxynonenal (4-HNE)
most toxic secondary product of lipid peroxidation, and it displays a dual role as a protective signaling molecule during gene expression and a cytotoxic promoter of pathological pathways.
282
Cancer cells
have increased levels of reactive oxygen species, indicating a connection between oxidative damage and abnormal cell growth
283
lipid peroxidation
The amount of ____ varies within cancer cells with different concentrations of 4-HNE can be found depending on the origin of tumor.
284
Consequences of lipid peroxidation
DNA damage and mutagenesis
285
cancer
leading cause of death in human beings
286
Cancer
characterized by cells that grow and divide out of control, often spreading to other tissues and causing them to become cancerous
287
Cancer cells
continue to grow and divide in situations in which normal cells do not
288
Cancer cells
cells continue to grow even when the neighboring cells send out “stop-growth” signals
289
Cancer cells
manage to keep going and avoid a “self-destruct” signal that usually occurs when DNA damage has occurred
290
Cancer cells
They can co-opt the body’s vascular system, causing the growth of new blood vessels to supply the cancerous cells with nutrients
291
Cancer cells
essentially immortal
292
metastasis
Cancer cells have the ability to break loose, travel to other parts of the body and create new tumors which make them lethal, this is called ____
293
DNA
Changes in ____cause changes to specific proteins that are responsible for controlling the cell cycle
294
Tumor suppressor, oncogene
Most mutations of DNA affect two types of genes:
295
Tumor suppressor
gene that makes a protein that restricts the cell’s ability to divide
296
oncogene
one whose protein product stimulates growth and cell division
297
Oncogene
Mutations of an ___ cause it to be permanently active
298
Tumor suppressor
inhibit transcription of genes that would cause increased replication
299
Replication and division
When a mutation occurs in any suppressor, ____and ____ become uncontrolled and tumors result
300
p53
Mutations in the ___ gene are found in more than 50% of all human cancers
301
3. Treatment with monoclonal antibodies to target specific tumors
Traditional approach to treat cancer
302
p53
More current foci include attempts to reactivate ___ in cancerous tissues when they have lost their function
303
Immortal cells, divide despite “stop growth” signals from nearby cells, spread to other parts of body
All potentially fatal cancers have several things in common
304
multiple breakdowns
The development of cancer requires _____ in normal metabolism
