The Cellular Level of Organization Flashcards
1
Q
active transport
A
form of transport across the cell membrane that requires input of cellular energy
2
Q
unipotent
A
describes the condition of being committed to a single specialized cell type
3
Q
vesicle
A
membrane-bound structure that contains materials within or outside of the cell
4
Q
triplet
A
consecutive sequence of three nucleotides on a DNA molecule that, when transcribed into an mRNA codon,
corresponds to a particular amino acid
5
Q
totipotent
A
embryonic cells that have the ability to differentiate into any type of cell and organ in the body
6
Q
transcription
A
process of producing an mRNA molecule that is complementary to a particular gene of DNA
7
Q
transcription factor
A
one of the proteins that regulate the transcription of genes
8
Q
transfer RNA (tRNA)
A
molecules of RNA that serve to bring amino acids to a growing polypeptide strand and properly
place them into the sequence
9
Q
translation
A
process of producing a protein from the nucleotide sequence code of an mRNA transcript
10
Q
osmosis
A
diffusion of water molecules down their concentration gradient across a selectively permeable membrane
11
Q
passive transport
A
form of transport across the cell membrane that does not require input of cellular energy
12
Q
peripheral protein
A
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
13
Q
peroxisome
A
membrane-bound organelle that contains enzymes primarily responsible for detoxifying harmful
substances
14
Q
phagocytosis
A
endocytosis of large particles
15
Q
pinocytosis
A
endocytosis of fluid
16
Q
pluripotent
A
describes the condition of being able to differentiate into a large variety of cell types
17
Q
telophase
A
final stage of mitosis (and meiosis), preceding cytokinesis, characterized by the formation of two new
daughter nuclei
18
Q
polypeptide
A
chain of amino acids linked by peptide bonds
19
Q
polyribosome
A
simultaneous translation of a single mRNA transcript by multiple ribosomes
20
Q
promoter
A
region of DNA that signals transcription to begin at that site within the gene
21
Q
prophase
A
first stage of mitosis (and meiosis), characterized by breakdown of the nuclear envelope and condensing of
the chromatin to form chromosomes
22
Q
spliceosome
A
complex of enzymes that serves to splice out the introns of a pre-mRNA transcript
23
Q
splicing
A
the process of modifying a pre-mRNA transcript by removing certain, typically non-coding, regions
24
Q
sodium-potassium pump
A
(also, Na+/K+ ATP-ase) membrane-embedded protein pump that uses ATP to move Na+
out of a cell and K+ into the cell
25
stem cell
cell that is oligo-, multi-, or pleuripotent that has the ability to produce additional stem cells rather than
becoming further specialized
26
all cells of the body excluding gamete cells
somatic cell
27
full complement of proteins produced by a cell (determined by the cell’s specific gene expression)
proteome
28
a group of extremely reactive peroxides and oxygen-containing radicals that may
contribute to cellular damage
reactive oxygen species (ROS)
29
protein molecule that contains a binding site for another specific molecule (called a ligand)
receptor
30
receptor-mediated endocytosis
endocytosis of ligands attached to membrane-bound receptors
31
feature of any barrier that allows certain substances to cross but excludes others
selective permeability
32
one of a pair of identical chromosomes, formed during DNA replication
sister chromatid
33
stage of the cell cycle during which DNA replication occurs
S phase
34
enzyme that unwinds DNA and then adds new nucleotides to a growing strand of RNA for the
transcription phase of protein synthesis
RNA polymerase
35
RNA that makes up the subunits of a ribosome
ribosomal RNA (rRNA)
36
ribosome
cellular organelle that functions in protein synthesis
37
describes a molecule that exhibits a difference in polarity between its two ends, resulting in a difference in
water solubility
amphipathic
38
third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of
a dividing cell
anaphase
39
consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on
an mRNA molecule
anticodon
40
breakdown of cells by their own enzymatic action
autolysis
41
lysosomal breakdown of a cell’s own components
autophagy
42
life cycle of a single cell, from its birth until its division into two new daughter cells
cell cycle
43
concentration gradient
difference in the concentration of a substance between two regions
44
cyclin
one of a group of proteins that function in the progression of the cell cycle
45
cyclin-dependent kinase (CDK)
one of a group of enzymes associated with cyclins that help them perform their
functions
46
cytokinesis
final stage in cell division, where the cytoplasm divides to form two separate daughter cells
47
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
48
cytoskeleton
“skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other
functions, locomotive abilities
49
cytosol
clear, semi-fluid medium of the cytoplasm, made up mostly of water
50
membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various
molecules; also known as plasma membrane
cell membrane
51
small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell
division
centriole
52
region of attachment for two sister chromatids
centromere
53
cellular structure that organizes microtubules during cell division
centrosome
54
membrane-spanning protein that has an inner pore which allows the passage of one or more
substances
channel protein
55
progress point in the cell cycle during which certain conditions must be met in order for the cell to proceed
to a subsequence phase
checkpoint
56
substance consisting of DNA and associated proteins
chromatin
57
condensed version of chromatin
chromosome
58
contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves
cleavage furrow
59
consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid
codon
60
small appendage on certain cells formed by microtubules and modified for movement of materials across the
cellular surface
cilia
61
movement of a substance from an area of higher concentration to one of lower concentration
diffusion
62
condition marked by the presence of a double complement of genetic material (two sets of chromosomes, one
set inherited from each of two parents)
diploid
63
enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA
replication
DNA polymerase
64
process of duplicating a molecule of DNA
DNA replication
65
difference in the electrical charge (potential) between two regions
electrical gradient
66
import of material into the cell by formation of a membrane-bound vesicle
endocytosis
67
unit of chromatin consisting of a DNA strand wrapped around histone proteins
nucleosome
68
cell’s central organelle; contains the cell’s DNA
nucleus
69
describes the condition of being more specialized than multipotency; the condition of being able to
differentiate into one of a few possible cell types
oligopotent
70
any of several different types of membrane-enclosed specialized structures in the cell that perform specific
organelle
71
small region of the nucleus that functions in ribosome synthesis
nucleolus
72
one of the small, protein-lined openings found scattered throughout the nuclear envelope
nuclear pore
73
membrane that surrounds the nucleus; consisting of a double lipid-bilayer
nuclear envelope
74
cellular organelle that consists of interconnected membrane-bound tubules, which may
or may not be associated with ribosomes (rough type or smooth type, respectively)
endoplasmic reticulum (ER)
75
export of a substance out of a cell by formation of a membrane-bound vesicle
exocytosis
76
one of the coding regions of an mRNA molecule that remain after splicing
exon
77
fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluid found in other
reservoirs in the body
extracellular fluid (ECF)
78
diffusion of a substance with the aid of a membrane protein
facilitated diffusion
79
appendage on certain cells formed by microtubules and modified for movement
flagellum
80
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
G0 phase
81
first phase of the cell cycle, after a new cell is born
G1 phase
82
change in the nucleotide sequence in a gene within a cell’s DNA
mutation
83
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
multipotent
84
network of microtubules, originating from centrioles, that arranges and pulls apart chromosomes
during mitosis
mitotic spindle
85
phase of the cell cycle in which a cell undergoes mitosis
mitotic phase
86
third phase of the cell cycle, after the DNA synthesis phase
G2 phase
87
functional length of DNA that provides the genetic information necessary to build a protein
gene
88
active interpretation of the information coded in a gene to produce a functional gene product
gene expression
89
entire complement of an organism’s DNA; found within virtually every cell
genome
90
coating of sugar molecules that surrounds the cell membrane
glycocalyx
91
the thickest of the cytoskeletal filaments, composed of tubulin subunits that function in cellular movement
and structural support
microtubule
92
one of the cellular organelles bound by a double lipid bilayer that function primarily in the production
of cellular energy (ATP)
mitochondrion
93
division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei
are formed
mitosis
94
the thinnest of the cytoskeletal filaments; composed of actin subunits that function in muscle
contraction and cellular structural support
microfilament
95
linear alignment of sister chromatids in the center of the cell, which takes place during metaphase
metaphase plate
96
second stage of mitosis (and meiosis), characterized by the linear alignment of sister chromatids in the
center of the cell
metaphase
97
protein that has one or more carbohydrates attached
| t
glycoprotein
98
cellular organelle formed by a series of flattened, membrane-bound sacs that functions in protein
modification, tagging, packaging, and transpor
Golgi apparatus
99
membrane-bound cellular organelle originating from the Golgi apparatus and containing digestive enzymes
lysosome
100
molecule that binds with specificity to a specific receptor molecule
ligand
101
region of a centromere where microtubules attach to a pair of sister chromatids
kinetochore
102
describes a solution concentration that is the same as a reference concentration
isotonic
103
nucleotide molecule that serves as an intermediate in the genetic code between DNA and
protein
messenger RNA (mRNA)
104
enzyme that functions to separate the two DNA strands of a double helix during DNA replication
helicase
105
family of proteins that associate with DNA in the nucleus to form chromatin
histone
106
describes two copies of the same chromosome (not identical), one inherited from each parent
homologous
107
describes a substance or structure attracted to water
hydrophilic
108
describes a substance or structure repelled by water
hydrophobic
109
describes a solution concentration that is higher than a reference concentration
hypertonic
110
entire life cycle of a cell, excluding mitosis
interphase
111
fluid in the cytosol of cells
intracellular fluid (ICF)
112
non-coding regions of a pre-mRNA transcript that may be removed during splicing
intron
113
fluid in the small spaces between cells not contained within blood vessels
interstitial fluid (IF)
114
type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and
playing a role in resisting cellular tension
intermediate filament
115
membrane-associated protein that spans the entire width of the lipid bilayer
integral protein
116
describes a solution concentration that is lower than a reference concentration
hypotonic
