Levels of Organization Flashcards
1
Q
chromatin
A
substance consisting of DNA and associated proteins
2
Q
chromosome
A
condensed version of chromatin
3
Q
DNA polymerase
A
enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA replication
4
Q
DNA replication
A
process of duplicating a molecule of DNA
5
Q
genome
A
entire complement of an organism’s DNA; found within virtually every cell
6
Q
helicase
A
enzyme that functions to separate the two DNA strands of a double helix during DNA replication
7
Q
histone
A
family of proteins that associate with DNA in the nucleus to form chromatin
8
Q
nuclear envelope
A
membrane that surrounds the nucleus; consisting of a double lipid-bilayer
9
Q
nuclear pore
A
one of the small, protein-lined openings found scattered throughout the nuclear envelope
10
Q
nucleolus
A
small region of the nucleus that functions in ribosome synthesis
11
Q
nucleosome
A
unit of chromatin consisting of a DNA strand wrapped around histone proteins
12
Q
anatomy
A
science that studies the form and composition of the body’s structures
13
Q
gross anatomy
A
study of the larger structures of the body, typically with the unaided eye; also referred to macroscopic anatomy
14
Q
homeostasis
A
steady state of body systems that living organisms maintain
15
Q
microscopic anatomy
A
study of very small structures of the body using magnification
16
Q
physiology
A
science that studies the chemistry, biochemistry, and physics of the body’s functions
17
Q
regional anatomy
A
study of the structures that contribute to specific body regions
18
Q
systemic anatomy
A
study of the structures that contribute to specific body systems
19
Q
cell
A
smallest independently functioning unit of all organisms; in animals, a cell contains cytoplasm, composed of fluid and organelles
20
Q
organ
A
functionally distinct structure composed of two or more types of tissues
21
Q
organ system
A
group of organs that work together to carry out a particular function
22
Q
organism
A
living being that has a cellular structure and that can independently perform all physiologic functions necessary for life
23
Q
tissue
A
group of similar or closely related cells that act together to perform a specific function
24
Q
anabolism
A
assembly of more complex molecules from simpler molecules
25
catabolism
breaking down of more complex molecules into simpler molecules
26
development
changes an organism goes through during its life
27
differentiation
process by which unspecialized cells become specialized in structure and function
28
growth
process of increasing in size
29
metabolism
sum of all of the body’s chemical reactions
30
renewal
process by which worn-out cells are replaced
31
reproduction
process by which new organisms are generated
32
responsiveness
ability of an organisms or a system to adjust to changes in conditions
33
nutrient
chemical obtained from foods and beverages that is critical to human survival
34
pressure
force exerted by a substance in contact with another substance
35
control center
compares values to their normal range; deviations cause the activation of an effector
36
effector
organ that can cause a change in a value
37
negative feedback
homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed
38
normal range
range of values around the set point that do not cause a reaction by the control center
39
positive feedback
mechanism that intensifies a change in the body’s physiological condition in response to a stimulus
40
sensor/recptor
reports a monitored physiological value to the control center
41
set point
ideal value for a physiological parameter; the level or small range within which a physiological parameter such as blood pressure is stable and optimally healthful, that is, within its parameters of homeostasis
42
abdominopelvic cavity
division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera
43
anatomical position
standard reference position used for describing locations and directions on the human body
44
anterior
describes the front or direction toward the front of the body; also referred to as ventral
45
anterior cavity
larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity
46
caudal
describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as inferior
47
cranial/superior
describes a position above or higher than another part of the body proper; also referred to as superior
48
cranial cavity
division of the posterior (dorsal) cavity that houses the brain
49
deep
describes a position farther from the surface of the body
50
distal
describes a position farther from the point of attachment or the trunk of the body
51
dorsal cavity
posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity
52
frontal plane
two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions
53
inferior
describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal
54
lateral
describes the side or direction toward the side of the body
55
medial
describes the middle or direction toward the middle of the body
56
pericardium
sac that encloses the heart
57
peritoneum
serous membrane that lines the abdominopelvic cavity and covers the organs found there
58
plane
imaginary two-dimensional surface that passes through the body
59
pleura
serous membrane that lines the pleural cavity and covers the lungs
60
posterior
describes the back or direction toward the back of the body; also referred to as dorsal
61
posterior cavity
posterior body cavity that houses the brain and spinal cord; also referred to as dorsal cavity
62
prone
face down
63
proximal
describes a position nearer to the point of attachment or the trunk of the body
64
sagittal plane
two-dimensional, vertical plane that divides the body or organ into right and left sides
65
section
in anatomy, a single flat surface of a three-dimensional structure that has been cut through
66
serous membrane
membrane that covers organs and reduces friction; also referred to as serosa
67
serosa
membrane that covers organs and reduces friction; also referred to as serous membrane
68
spinal cavity
division of the dorsal cavity that houses the spinal cord; also referred to as vertebral cavity
69
superficial
describes a position nearer to the surface of the body
70
superior
describes a position above or higher than another part of the body proper; also referred to as cranial
71
supine
face up
72
thoracic cavity
division of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea
73
transverse plane
two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions
74
ventral
describes the front or direction toward the front of the body; also referred to as anterior
75
ventral cavity
larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity
76
computed tomography (CT)
medical imaging technique in which a computer-enhanced cross-sectional X-ray image is obtained
77
magnetic resonance imaging (MRI)
medical imaging technique in which a device generates a magnetic field to obtain detailed sectional images of the internal structures of the body
78
positron emission tomography (PET)
medical imaging technique in which radiopharmaceuticals are traced to reveal metabolic and physiological functions in tissues
79
ultrasonography
application of ultrasonic waves to visualize subcutaneous body structures such as tendons and organs
80
X-ray
form of high energy electromagnetic radiation with a short wavelength capable of penetrating solids and ionizing gases; used in medicine as a diagnostic aid to visualize body structures such as bones
81
atom
smallest unit of an element that retains the unique properties of that element
82
atomic number
number of protons in the nucleus of an atom
83
compound
substance composed of two or more different elements joined by chemical bonds
84
electron
subatomic particle having a negative charge and nearly no mass; found orbiting the atom’s nucleus
85
electron shell
area of space a given distance from an atom’s nucleus in which electrons are grouped
86
element
substance that cannot be created or broken down by ordinary chemical means
87
isotope
one of the variations of an element in which the number of neutrons differ from each other
88
mass number
sum of the number of protons and neutrons in the nucleus of an atom
89
matter
physical substance; that which occupies space and has mass
90
neutron
heavy subatomic particle having no electrical charge and found in the atom’s nucleus
91
proton
heavy subatomic particle having a positive charge and found in the atom’s nucleus
92
radioactive isotope
unstable, heavy isotope that gives off subatomic particles, or electromagnetic energy, as it decays; also called radioisotopes
93
valence shell
outermost electron shell of an atom
94
anion
atom with a negative charge
95
bond
electrical force linking atoms
96
cation
atom with a positive charge
97
covalent bond
chemical bond in which two atoms share electrons, thereby completing their valence shells
98
hydrogen bond
dipole-dipole bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom
99
ion
atom with an overall positive or negative charge
100
ionic bond
attraction between an anion and a cation
101
molecule
two or more atoms covalently bonded together
102
polar molecule
molecule with regions that have opposite charges resulting from uneven numbers of electrons in the nuclei of the atoms participating in the covalent bond
103
activation energy
amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed
104
catalyst
substance that increases the rate of a chemical reaction without itself being changed in the process
105
chemical energy
form of energy that is absorbed as chemical bonds form, stored as they are maintained, and released as they are broken
106
decomposition reaction
type of catabolic reaction in which one or more bonds within a larger molecule are broken, resulting in the release of smaller molecules or atoms
107
enzyme
protein or RNA that catalyzes chemical reactions
108
exchange reaction
type of chemical reaction in which bonds are both formed and broken, resulting in the transfer of components
109
reactant
one or more substances that enter into the reaction
110
product
one or more substances produced by a chemical reaction
111
synthesis reaction
type of anabolic reaction in which two or more atoms or molecules bond, resulting in the formation of a larger molecule
112
acid
compound that releases hydrogen ions (H+) in solution
113
base
compound that accepts hydrogen ions (H+) in solution
114
buffer
solution containing a weak acid or a weak base that opposes wide fluctuations in the pH of body fluids
115
colloid
liquid mixture in which the solute particles consist of clumps of molecules large enough to scatter light
116
inorganic compound
substance that does not contain both carbon and hydrogen
117
organic compound
substance that contains both carbon and hydrogen
118
pH
negative logarithm of the hydrogen ion (H+) concentration of a solution
119
solution
homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent
120
suspension
liquid mixture in which particles distributed in the liquid settle out over time
121
adenosine triphosphate (ATP)
nucleotide containing ribose and an adenine base that is essential in energy transfer
122
amino acid
building block of proteins; characterized by an amino and carboxyl functional groups and a variable side-chain
123
carbohydrate
class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio
124
denaturation
change in the structure of a molecule through physical or chemical means
125
deoxyribonucleic acid (DNA)
deoxyribose-containing nucleotide that stores genetic information
126
disaccharide
pair of carbohydrate monomers bonded by dehydration synthesis via a glycosidic bond
127
disulfide bond
covalent bond formed within a polypeptide between sulfide groups of sulfur-containing amino acids, for example, cysteine
128
functional group
group of atoms linked by strong covalent bonds that tends to behave as a distinct unit in chemical reactions with other atoms
129
lipid
class of nonpolar organic compounds built from hydrocarbons and distinguished by the fact that they are not soluble in water
130
macromolecule
large molecule formed by covalent bonding
131
monosaccharide
monomer of carbohydrate; also known as a simple sugar
132
nucleotide
class of organic compounds composed of one or more phosphate groups, a pentose sugar, and a base
133
peptide bond
covalent bond formed by dehydration synthesis between two amino acids
134
phospholipid
a lipid compound in which a phosphate group is combined with a diglyceride
135
phosphorylation
addition of one or more phosphate groups to an organic compound
136
polysaccharide
compound consisting of more than two carbohydrate monomers bonded by dehydration synthesis via glycosidic bonds
137
prostaglandin
lipid compound derived from fatty acid chains and important in regulating several body processes
138
protein
class of organic compounds that are composed of many amino acids linked together by peptide bonds
139
purine
nitrogen-containing base with a double ring structure; adenine and guanine
140
pyrimidine
nitrogen-containing base with a single ring structure; cytosine, thiamine, and uracil
141
ribonucleic acid (RNA)
ribose-containing nucleotide that helps manifest the genetic code as protein
142
steroid
(also, sterol) lipid compound composed of four hydrocarbon rings bonded to a variety of other atoms and molecules
143
substrate
reactant in an enzymatic reaction
144
triglyceride
lipid compound composed of a glycerol molecule bonded with three fatty acid chains
145
active transport
form of transport across the cell membrane that requires input of cellular energy
146
amphipathic
describes a molecule that exhibits a difference in polarity between its two ends, resulting in a difference in water solubility
147
cell membrane
membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane
148
channel protein
membrane-spanning protein that has an inner pore which allows the passage of one or more substances
149
concentration gradient
difference in the concentration of a substance between two regions
150
diffusion
movement of a substance from an area of higher concentration to one of lower concentration
151
endocytosis
import of material into the cell by formation of a membrane-bound vesicle
152
exocytosis
export of a substance out of a cell by formation of a membrane-bound vesicle
153
extracellular fluid (ECF)
fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluid found in other reservoirs in the body
154
facilitated diffusion
diffusion of a substance with the aid of a membrane protein
155
glycocalyx
coating of sugar molecules that surrounds the cell membrane
156
glycoprotein
protein that has one or more carbohydrates attached
157
hydrophilic
describes a substance or structure attracted to water
158
hydrophobic
describes a substance or structure repelled by water
159
hypertonic
describes a solution concentration that is higher than a reference concentration
160
hypotonic
describes a solution concentration that is lower than a reference concentration
161
integral protein
membrane-associated protein that spans the entire width of the lipid bilayer
162
interstitial fluid (IF)
fluid in the small spaces between cells not contained within blood vessels
163
intracellular fluid (ICF)
fluid in the cytosol of cells
164
isotonic
describes a solution concentration that is the same as a reference concentration
165
ligand
molecule that binds with specificity to a specific receptor molecule
166
osmosis
diffusion of molecules down their concentration across a selectively permeable membrane
167
passive transport
form of transport across the cell membrane that does not require input of cellular energy
168
peripheral protein
membrane-associated protein that does not span the width of the lipid bilayer, but is attached peripherally to integral proteins, membrane lipids, or other components of the membrane
169
phagocytosis
endocytosis of large particles
170
pinocytosis
endocytosis of fluid
171
receptor
protein molecule that contains a binding site for another specific molecule (called a ligand)
172
receptor-mediated endocytosis
endocytosis of ligands attached to membrane-bound receptors
173
selective permeability
feature of any barrier that allows certain substances to cross but excludes others
174
sodium-potassium pump
(also, Na+/K+ ATP-ase) membrane-embedded protein pump that uses ATP to move Na+ out of a cell and K+ into the cell
175
vesicle
membrane-bound structure that contains materials within or outside of the cell
176
autolysis
breakdown of cells by their own enzymatic action
177
autophagy
lysosomal breakdown of a cell’s own components
178
centriole
small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division
179
cilia
small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface
180
cytoplasm
internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular solute and suspended materials
181
cytoskeleton
“skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other functions, locomotive abilities
182
cytosol
clear, semi-fluid medium of the cytoplasm, made up mostly of water
183
endoplasmic reticulum (ER)
cellular organelle that consists of interconnected membrane-bound tubules, which may or may not be associated with ribosomes (rough type or smooth type, respectively)
184
flagellum
appendage on certain cells formed by microtubules and modified for movement
185
Golgi apparatus
cellular organelle formed by a series of flattened, membrane-bound sacs that functions in protein modification, tagging, packaging, and transport
186
intermediate filament
type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and playing a role in resisting cellular tension
187
lysosome
membrane-bound cellular organelle originating from the Golgi apparatus and containing digestive enzymes
188
microfilament
the thinnest of the cytoskeletal filaments; composed of actin subunits that function in muscle contraction and cellular structural support
189
microtubule
the thickest of the cytoskeletal filaments, composed of tubulin subunits that function in cellular movement and structural support
190
mitochondrion
one of the cellular organelles bound by a double lipid bilayer that function primarily in the production of cellular energy (ATP)
191
mutation
change in the nucleotide sequence in a gene within a cell’s DNA
192
nucleus
cell’s central organelle; contains the cell’s DNA
193
organelle
any of several different types of membrane-enclosed specialized structures in the cell that perform specific functions for the cell
194
peroxisome
membrane-bound organelle that contains enzymes primarily responsible for detoxifying harmful substances
195
reactive oxygen species (ROS)
a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage
196
ribosome
cellular organelle that functions in protein synthesis
197
anticodon
consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on an mRNA molecule
198
codon
consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid
199
exon
one of the coding regions of an mRNA molecule that remain after splicing
200
gene
functional length of DNA that provides the genetic information necessary to build a protein
201
gene expression
active interpretation of the information coded in a gene to produce a functional gene product
202
intron
non-coding regions of a pre-mRNA transcript that may be removed during splicing
203
messenger RNA (mRNA)
nucleotide molecule that serves as an intermediate in the genetic code between DNA and protein
204
polypeptide
chain of amino acids linked by peptide bonds
205
polyribosome
simultaneous translation of a single mRNA transcript by multiple ribosomes
206
promoter
region of DNA that signals transcription to begin at that site within the gene
207
proteome
full complement of proteins produced by a cell (determined by the cell’s specific gene expression)
208
ribosomal RNA (rRNA)
RNA that makes up the subunits of a ribosome
209
RNA polymerase
enzyme that unwinds DNA and then adds new nucleotides to a growing strand of RNA for the transcription phase of protein synthesis
210
spliceosome
complex of enzymes that serves to splice out the introns of a pre-mRNA transcript
211
splicing
the process of modifying a pre-mRNA transcript by removing certain, typically non-coding, regions
212
transcription
process of producing an mRNA molecule that is complementary to a particular gene of DNA
213
transfer RNA (tRNA)
molecules of RNA that serve to bring amino acids to a growing polypeptide strand and properly place them into the sequence
214
translation
process of producing a protein from the nucleotide sequence code of an mRNA transcript
215
triplet
consecutive sequence of three nucleotides on a DNA molecule that, when transcribed into an mRNA codon, corresponds to a particular amino acid
216
anaphase
third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell
217
cell cycle
life cycle of a single cell, from its birth until its division into two new daughter cells
218
centromere
region of attachment for two sister chromatids
219
centrosome
cellular structure that organizes microtubules during cell division
220
checkpoint
progress point in the cell cycle during which certain conditions must be met in order for the cell to proceed to a subsequence phase
221
cleavage furrow
contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves
222
cyclin
one of a group of proteins that function in the progression of the cell cycle
223
cyclin-dependent kinase (CDK)
one of a group of enzymes associated with cyclins that help them perform their functions
224
cytokinesis
final stage in cell division, where the cytoplasm divides to form two separate daughter cells
225
diploid
condition marked by the presence of a double complement of genetic material (two sets of chromosomes, one set inherited from each of two parents)
226
G0 phase
phase of the cell cycle, usually entered from the G1 phase; characterized by long or permanent periods where the cell does not move forward into the DNA synthesis phase
227
G1 phase
first phase of the cell cycle, after a new cell is born
228
G2 phase
third phase of the cell cycle, after the DNA synthesis phase
229
homologous
describes two copies of the same chromosome (not identical), one inherited from each parent
230
interphase
entire life cycle of a cell, excluding mitosis
231
kinetochore
region of a centromere where microtubules attach to a pair of sister chromatids
232
metaphase
second stage of mitosis (and meiosis), characterized by the linear alignment of sister chromatids in the center of the cell
233
metaphase plate
linear alignment of sister chromatids in the center of the cell, which takes place during metaphase
234
mitosis
division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed
235
mitotic phase
phase of the cell cycle in which a cell undergoes mitosis
236
mitotic spindle
network of microtubules, originating from centrioles, that arranges and pulls apart chromosomes during mitosis
237
prophase
first stage of mitosis (and meiosis), characterized by breakdown of the nuclear envelope and condensing of the chromatin to form chromosomes
238
S phase
stage of the cell cycle during which DNA replication occurs
239
sister chromatid
one of a pair of identical chromosomes, formed during DNA replication
240
somatic cell
all cells of the body excluding gamete cells
241
telophase
final stage of mitosis (and meiosis), preceding cytokinesis, characterized by the formation of two new daughter nuclei
242
multipotent
describes the condition of being able to differentiate into different types of cells within a given cell lineage or small number of lineages, such as a red blood cell or white blood cell
243
oligopotent
describes the condition of being more specialized than multipotency; the condition of being able to differentiate into one of a few possible cell types
244
pluripotent
describes the condition of being able to differentiate into a large variety of cell types
245
stem cell
cell that is oligo-, multi-, or pleuripotent that has the ability to produce additional stem cells rather than becoming further specialized
246
totipotent
embryonic cells that have the ability to differentiate into any type of cell and organ in the body
247
transcription factor
one of the proteins that regulate the transcription of genes
248
unipotent
describes the condition of being committed to a single specialized cell type
