Chapter 3 Flashcards
1
Q
What is the cell membrane?
A
The extremely pliable structure composed primarily of back-to-back phospholipids that encloses a cell.
2
Q
What is hydrophilic?
A
Attracted to water. Polar.
3
Q
What is hydrophobic?
A
Repels and is repelled by water. Nonpolar.
4
Q
What is amphipathic?
A
A molecule that contains both a hydrophobic and hydrophilic region. Hydrophilic portion can dissolve in water and the hydrophobic region can trap oil.
5
Q
What is intracellular fluid?
A
Fluid interior of the cell
6
Q
What is extracellular fluid?
A
Fluid environment outside the enclosure of the cell membrane
7
Q
What is interstitial fluid?
A
Extracellular fluid not contained within blood vessels
8
Q
What is the phospholipid bilayer?
A
Consists of two adjacent sheets of phospholipids arranged tail to tail. Hydrophobic tails associate with one another and form the interior of the membrane. Polar heads contact the fluid outside and inside of the cell
9
Q
What is a phospholipid?
A
Molecule that consists of a polar, hydrophilic phosphate head (phosphate + glycerol) and a nonpolar hydrophobic lipid tail (unsaturated fatty acid and saturated fatty acid). Unsaturated fatty acids result in kinks in the tail.
10
Q
What is an integral protein?
A
A protein that is embedded in the cell membrane
11
Q
What is a channel protein?
A
An integral protein that selectively allows particular materials to pass in and out of the cell through the cell membrane.
12
Q
What is a glycoprotein?
A
A protein with a carbohydrate attached
13
Q
What is a glycolipid?
A
A lipid with a carbohydrate attached
14
Q
What is a peripheral membrane protein?
A
A protein that is typically found on the inner or outer surface of the lipid bilayer but can also be attached to the internal or external surface as an integral protein.
15
Q
What is selective permeability?
A
Only allows substances meeting a certain criteria to pass through a membrane unaided
16
Q
What is passive transport?
A
The movement of substances across the membrane without the expenditure of cellular energy
17
Q
What is active transport?
A
The movement of substances across the membrane using energy from ATP
18
Q
What is a concentration gradient?
A
Difference in concentration of a substance across a space
19
Q
What is diffusion?
A
The movement of particles from an area of higher concentration to an area of lower concentration - move down the concentration gradient
20
Q
What is facilitated diffusion?
A
The diffusion process used for substances that cannot cross the lipid bilayer due to their size, charge, or polarity, through specific transmembrane proteins
21
Q
What is simple diffusion?
A
The process by which molecules, atoms, or ions diffuse through a selectively permeable membrane down their concentration gradient without the assistance of transporter proteins
22
Q
What is osmosis?
A
The diffusion of water through a semipermeable membrane. Occurs when there is an imbalance of solutes outside of a cell versus inside the cell
23
Q
What is isotonic?
A
Two solutions that have the same concentration of solutes - “equal tension”
24
Q
What is hypertonic?
A
A solution that has a higher concentration of solutes than another solution. Water molecules tend to diffuse into.
25
What is hypotonic?
A solution that has a lower concentration of solutes than another solution. Water molecules tend to diffuse out of.
26
What is anaphase?
third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell
27
What is an anticodon?
consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on an mRNA molecule
28
What is autolysis?
breakdown of cells by their own enzymatic action
29
What is autophagy?
lysosomal breakdown of a cell’s own components
30
What is the cell cycle?
life cycle of a single cell, from its birth until its division into two new daughter cells
31
What is the cell membrane?
membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane
32
What is a centriole?
small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division
33
What is a centromere?
region of attachment for two sister chromatids
34
What is a centrosome?
cellular structure that organizes microtubules during cell division
35
What is a channel protein?
membrane-spanning protein that has an inner pore which allows the passage of one or more substances
36
What is a 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
37
What is chromatin?
substance consisting of DNA and associated proteins
38
What is a chromosome?
condensed version of chromatin
39
What are cilia?
small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface
40
What is the cleavage furrow?
contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves
41
What is a codon?
consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid
42
What is cyclin?
one of a group of proteins that function in the progression of the cell cycle
43
What is cyclin-dependent kinase (CDK)?
one of a group of enzymes associated with cyclins that help them perform their functions
44
What is cytokinesis?
final stage in cell division, where the cytoplasm divides to form two separate daughter cells
45
What is the 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
46
What is the cytoskeleton?
“skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other functions, locomotive abilities
47
What is cytosol?
clear, semi-fluid medium of the cytoplasm, made up mostly of water
48
What is a 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)
49
What is DNA polymerase?
enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA replication
50
What is DNA replication?
process of duplicating a molecule of DNA
51
What is the electrical gradient?
difference in electrical charge across a space.
52
What is endocytosis?
(bringing “into the cell”) is the process of a cell ingesting material by enveloping it in a portion of its cell membrane, and then pinching off that portion of membrane
53
What is the 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)
54
What is exocytosis?
(taking “out of the cell”) is the process of a cell exporting material using vesicular transport
55
What is an exon?
one of the coding regions of an mRNA molecule that remain after splicing
56
What is extracellular fluid (ECF)?
fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluid found in other reservoirs in the body
57
What is a flagellum?
appendage on certain cells formed by microtubules and modified for movement
58
What is 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
59
What is G1 phase?
first phase of the cell cycle, after a new cell is born. Cell carries out all of its necessary functions. Cell is not actively dividing
60
What is G2 phase?
third phase of the cell cycle, after the DNA synthesis phase. second gap phase, during which the cell continues to grow and makes the necessary preparations for mitosis.
61
What is a gene?
functional length of DNA that provides the genetic information necessary to build a protein
62
What is gene expression?
active interpretation of the information coded in a gene to produce a functional gene product
63
What is a genome?
entire complement of an organism’s DNA; found within virtually every cell
64
What is a glycocalyx?
coating of sugar molecules that surrounds the cell membrane
65
What is a glycoprotein?
protein that has one or more carbohydrates attached
66
What is the Golgi apparatus?
cellular organelle formed by a series of flattened, membrane-bound sacs that functions in protein modification, tagging, packaging, and transport
67
What is helicase?
enzyme that functions to separate the two DNA strands of a double helix during DNA replication
68
What is a histone?
family of proteins that associate with DNA in the nucleus to form chromatin
69
What is homologous?
describes two copies of the same chromosome (not identical), one inherited from each parent
70
What is an intermediate filament?
type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and playing a role in resisting cellular tension
71
What is interphase?
entire life cycle of a cell, excluding mitosis
72
What is interstitial fluid (IF)?
fluid in the small spaces between cells not contained within blood vessels
73
What is intracellular fluid (ICF)?
the fluid interior of the cell
74
What is an intron?
non-coding regions of a pre-mRNA transcript that may be removed during splicing
75
What is a kinetochore?
region of a centromere where microtubules attach to a pair of sister chromatids
76
What is a ligand?
molecule that binds with specificity to a specific receptor molecule
77
What is a lysosome?
membrane-bound cellular organelle originating from the Golgi apparatus and containing digestive enzymes
78
What is messenger RNA (mRNA)?
nucleotide molecule that serves as an intermediate in the genetic code between DNA and protein
79
What is metaphase?
second stage of mitosis (and meiosis), characterized by the linear alignment of sister chromatids in the center of the cell
80
What is the metaphase plate?
linear alignment of sister chromatids in the center of the cell, which takes place during metaphase
81
What is a microfilament?
the thinnest of the cytoskeletal filaments; composed of actin subunits that function in muscle contraction and cellular structural support
82
What is a microtubule?
the thickest of the cytoskeletal filaments, composed of tubulin subunits that function in cellular movement and structural support
83
What is a mitochondrion?
one of the cellular organelles bound by a double lipid bilayer that function primarily in the production of cellular energy (ATP)
84
What is mitosis?
division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed
85
What is the mitotic phase?
phase of the cell cycle in which a cell undergoes mitosis
86
What is the mitotic spindle?
network of microtubules, originating from centrioles, that arranges and pulls apart chromosomes during mitosis
87
What is 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
88
What is a mutation?
change in the nucleotide sequence in a gene within a cell’s DNA
89
What is the nuclear envelope?
membrane that surrounds the nucleus; consisting of a double lipid-bilayer
90
What is a nuclear pore?
one of the small, protein-lined openings found scattered throughout the nuclear envelope
91
What is the nucleolus?
small region of the nucleus that functions in ribosome synthesis
92
What is a nucleosome?
unit of chromatin consisting of a DNA strand wrapped around histone proteins
93
What is the nucleus?
cell’s central organelle; contains the cell’s DNA
94
What is 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
95
What is an organelle?
any of several different types of membrane-enclosed specialized structures in the cell that perform specific functions for the cell
96
What is osmosis?
diffusion of water molecules down their concentration gradient across a selectively permeable membrane
97
What is a peroxisome?
membrane-bound organelle that contains enzymes primarily responsible for detoxifying harmful substances
98
What is phagocytosis?
(“cell eating”) is the endocytosis of large particles.
99
What is pinocytosis?
(“cell drinking”) brings fluid containing dissolved substances into a cell through membrane vesicles.
100
What is pluripotent?
describes the condition of being able to differentiate into a large variety of cell types
101
What is a polypeptide?
chain of amino acids linked by peptide bonds
102
What is a polyribosome?
simultaneous translation of a single mRNA transcript by multiple ribosomes
103
What is a promoter?
region of DNA that signals transcription to begin at that site within the gene
104
What is prophase?
first stage of mitosis (and meiosis), characterized by breakdown of the nuclear envelope and condensing of the chromatin to form chromosomes.
105
What is a proteome?
full complement of proteins produced by a cell (determined by the cell’s specific gene expression)
106
What is a reactive oxygen species (ROS)?
a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage
107
What is a receptor?
protein molecule that contains a binding site for another specific molecule (called a ligand)
108
What is receptor-mediated endocytosis?
endocytosis by a portion of the cell membrane that contains many receptors that are specific for a certain substance.
109
What is ribosomal RNA (rRNA)?
RNA that makes up the subunits of a ribosome
110
What is a ribosome?
cellular organelle that functions in protein synthesis
111
What is RNA polymerase?
enzyme that unwinds DNA and then adds new nucleotides to a growing strand of RNA for the transcription phase of protein synthesis
112
What is S phase?
stage of the cell cycle during which DNA replication occurs - synthesis phase
113
What is selective permeability?
feature of any barrier that allows certain substances to cross but excludes others
114
What is a sister chromatid?
one of a pair of identical chromosomes, formed during DNA replication
115
What is the sodium-potassium pump?
transports sodium out of a cell while moving potassium into the cell. found in the membranes of many types of cells - Na+/K+ ATPase,
116
What is a somatic cell?
all cells of the body excluding gamete cells
117
What is a spliceosome?
complex of enzymes that serves to splice out the introns of a pre-mRNA transcript
118
What is splicing?
the process of modifying a pre-mRNA transcript by removing certain, typically non-coding, regions
119
What is a stem cell?
cell that is oligo-, multi-, or pleuripotent that has the ability to produce additional stem cells rather than becoming further specialized
120
What is telophase?
final stage of mitosis (and meiosis), preceding cytokinesis, characterized by the formation of two new daughter nuclei
121
What is totipotent?
embryonic cells that have the ability to differentiate into any type of cell and organ in the body
122
What is transcription?
process of producing an mRNA molecule that is complementary to a particular gene of DNA
123
What is a transcription factor?
one of the proteins that regulate the transcription of genes
124
What is transfer RNA (tRNA)?
molecules of RNA that serve to bring amino acids to a growing polypeptide strand and properly place them into the sequence
125
What is translation?
process of producing a protein from the nucleotide sequence code of an mRNA transcript
126
What is a triplet?
consecutive sequence of three nucleotides on a DNA molecule that, when transcribed into an mRNA codon, corresponds to a particular amino acid
127
What is unipotent?
describes the condition of being committed to a single specialized cell type
128
What is a vesicle?
membranous sac—a spherical and hollow organelle bounded by a lipid bilayer membrane.
