CELLS Flashcards
(112 cards)
1
Q
structural and functional unit of the human body
A
cell
2
Q
they carry out the chemical activities needed to sustain life, and they divide to form or repair tissues.
A
cell
3
Q
the human body contains __ to ___ trillion of cells.
A
50 to 100
4
Q
he coined the term “cells” through plant tissue, cork, which resembles monk’s rooms.
A
Robert Hooke
5
Q
this principle states that the activities of the cells are dictated by their structure (anatomy), which determines function (physiology).
A
Principle of Complementarity
6
Q
the continuity of life has a _________.
A
cellular basis
7
Q
loss of of cell homeostasis underlies every _______.
A
disease
8
Q
cells are made of four primary elements:
A
carbon, oxygen, hydrogen, and nitrogen
9
Q
true or false: no one cell type is exactly like all others, but cells do have the same basic parts, and there are certain functions common to all cells.
A
true
10
Q
In general, there are three main regions or parts in all cells:
A
nucleus, plasma membrane, and the cytoplasm
11
Q
is usually located near the center of the cell
A
nucleus
12
Q
nucleus is surrounded by the semifluid called _______.
A
cytosol
13
Q
forms the outer cell boundary
A
plasma membrane
14
Q
head quarters or the control center of the cell, it contains the genetic material or DNA.
A
nucleus
15
Q
blueprint that contains all the instructions needed for building the whole body.
A
Deoxyribonucleic acid
16
Q
DNA has _________, which carries the instructions for building proteins.
A
Genes
17
Q
necessary for cell production
A
DNA
18
Q
a cell that has lost or ejected its nucleus is destined to _____________.
A
self-destruct
19
Q
The nucleus has three recognizable regions or structures:
A
nuclear envelope, nucleolus, and chromatin
20
Q
is a double membrane or also called as the ___________.
A
nuclear envelope
21
Q
when two layers of the nuclear envelope fuse, it generates openings called ___________.
A
nuclear pores
22
Q
the nuclear membrane encloses a jelly-like fluid called __________, in which other nuclear elements are suspended.
A
nucleoplasm
23
Q
dark-staining, round bodies that is the site where ribosomes are assembled.
A
nucleoli (plural: nucleolus)
24
Q
true or false: most ribosomes migrate to the cytoplasm, where they serve as the actual site of protein synthesis.
A
true
25
when cells do not divide, its DNA is carefully wounded around proteins called ____________.
histones
26
loose network of "beads on a string" that is scattered throught the nucleus.
chromatin
27
when a cell is not dividing to form a two daughter cells, the chromatin threads coil and form rod-like bodies called ____________.
chromosomes
28
is a fragile, transparent barrier that contains the cell contents and separates them from surrounding environment.
plasma membrane
29
cell's surface or outer limiting membrane
plasma membrane
30
although is defines the limits of the cell, it is more than a passive envelope or "baggie."
plasma membrane
31
the structure of plasma mebrane consists of two ____________ layers arranged "tail to tail," with cholesterol and floating proteins.
phospolipid
32
sugar groups attached to phospholipids
glycolipids
33
true or false: proteins that freely move in the lipid layer form a constantly changing pattern or mosaic, hence the name of the model, "The Fluid Mosaic Model."
true
34
true or false: phospholipids are polar molecules and its charged end interacts with water, while the fatty acid chains do not.
true
35
it is the property of ____________ that makes phospholipids a good foundation for cell membranes.
Polarity
36
these are the heads or called the "hydrophilic" (water-loving), the main component of both the intra and extracellular fluids.
Polar heads
37
these are the tails that are hydrophobic (water-fearing), it avoids water and line up in the center of the membrane.
Nonpolar tails
38
the ___________ property of the phospholipids allows biological membranes to reseal themselves quickly when torn.
self-orienting
39
true or false: the hydrophobic makeup of the membrane interior makes the plasma membrane relatively impermeable to most water-soluble molecules.
true
40
the ___________ scattered in the lipid bilayer are responsible for most specialized functions of the membrane.
protein
41
true or false: some proteins are enyzmes
true
42
true or false: some proteins protruding from the cell exterior are RECEPTORS for hormones.
true
43
true or false: proteins are CHEMICAL MESSENGERS or BINDING SITES for anchoring the cell to fibers.
true
44
a medium where water and small water-soluble molecules or ions can move.
protein channels
45
other proteins act as ____________ that bind to a substance and move it through the membrane.
carriers
46
true or false: glycoproteins and glycocalyx act as an adhesive or cellular glue.
true
47
these protein determines your blood type.
glycoproteins
47
sugar proteins are also called:
glycocalyx
48
are "footloose" in the body, many other types, particularly epithelial cells, are knit into tight communities.
cell membrane junctions
48
true or false: wavy contours of the membranes of adjacent cells fit together in a tongue-and-groove fashion.
true
49
are impermeable junctions that encircles the cells and bind them together into leakproof sheets.
tight junctions
49
adjacent plasma membrane fuse together in this junction in order to prevent substances from passing through the extracellular space between cells.
tight junctions
50
true or false: one example of tight junctions is the small intestine where the junctions prevent digestive enzymes from seeping into the bloodstream.
true
51
these junctions are scattered like rivents along the sides of adjacent cells. they prevent cells from mechanical stress.
desmosomes
52
true or false: demosomes in structure are button-like thickenings of adjacent plasma membranes that are connected by fine protein filaments.
true
53
these junctions allow communication between neighboring cells. they are commonly found in the heart and embryonic cells.
gap junctions
54
true or false: the structure of gap junctions is where the neighboring cells are connected by hollow cylinders composed of proteins (connexons).
true
55
____________ are also called transmembrane proteins because they span the entire width of abutting membranes in the gap junction's structure.
connexons
56
true or false: chemical molecules such as nutrients or ions, can pass directly through the water-filled connexon channels from one cell to another.
true
57
is the cellular material outside the nucleus and inside the plasma membrane. it is the site of most cellular activities.
cytoplasm
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"factory floor" of the cell
cytoplasm
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three major components of cytoplasm:
cytosol, inclusions, and organelles
60
is the semitransparent fluid that suspends the other elements.
cytosol
61
are chemical substances that may or may not be present, depending on the specific cell type. most _____ are stored nutrients or cell products floating in the cytosol.
inclusions
62
"cellular pantry" of the cell where items are kept in hand until needed.
inclusions
63
_____________ are specialized cellular compartments that are the metabolic machinery of the cell.
organelles
64
the _________ of organelles is crucial to their ability to perform their specialized functions for the cell.
compartmentalization
65
"cellular factory" of the cell
organelles
66
___________ are usually depicted as tiny, lozenge-like or sausage-shaped organelles.
mitochondrion (plural: mitochondria)
67
true or false: the mitochondria wall consists of a double membrane, equal to two plasma membranes placed side by side.
true
68
ttue or false: the outermembrane of mitochondira is smooth and featureless.
true
69
the innermembrane of mitochondria has shelf-like protrusions called ______________.
cristae
70
true or false: when food is broken and energy is released, much of this energy escapes as heat, but some is captured and used to from ATP molecules.
true
71
what provides the energy for all cellular work?
ATP
72
"power houses" of the cell
mitochondria
73
true or false: metabolically "busy," cells, such as liver, and muscle cells, use huge amounts of ATP and have hundred of mitchondria.
true
74
_________are tiny, bilobed, dark bodies made of proteins and one variety of RNA called ribosomal RNA.
ribosomes
75
are the actual sites of protein synthesis in the cell. the ____________ that float freely in the cytoplasm manufacture proteins that function inside the cell, while others attach to membranes.
ribosomes
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_________ is a system of fluid-filled tunnels that coil and twist through the cytoplasm. it is continuous with the nuclear envelope.
ER
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"mini circulatory system" of the cell since it provides a network of channels for carrying substances from one part of the cell to another.
ER
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studded with ribosomes
rough ER
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in this ER, cellular membranes are formed either in it or on it.
rough ER
80
"cell's membrane" factory
rough ER
81
small "sacs" of membraned called ________ that carry substances around the cell.
transport vesicles
82
true or false: rough ER is especially abundant in cells that make (synthesize) and excrete (secrete) digestive enzymes to be delivered to the small intestine.
true
83
true or false: smooth ER communicates with rough variety, but it plays no role in the protein synthesis.
true
84
________ functions in detoxification of drugs and pesticides.
smooth ER
85
true or false: liver cells are full of smooth ER.
true
86
appears as stack of flatenned membranous sacs that are associated with swarms of tiny vesicles.
golgi apparatus
87
close to the ER and is the principal "traffic director" for cellular proteins.
golgi apparatus
88
the major function of this organelle is to modify, package, andd ship proteins (sent to it by the rough ER via tranport vesicles).
golgi apparatus
89
all proteins leaving the golgi apparatus accumulate in sacs called ________.
golgi vesicles
90
when proteins are tagged for export accumulate in the golgi apparatus, the sacs swell. the swollen ends then pinch off to form _____________, which travel to the plasma membrane.
secretory vesicles
91
membranous "bags" containing powerful digestive enzymes. it is capable of digesting worn-out or nonusable cell structures and foreign substances.
lysosomes
92
"stomachs" of the cell
lysosomes
93
__________ are especially abundant in white blood cells called phagocytes.
lysosomes
94
membranous sacs containing powerful oxidase enzymes that use molecular oxygen to detoxify a number of harmful or poisonous substances such as alcohol and formaldehyde.
peroxisomes
95
most important function of this ogranelle is to "disarm" dangerous free radicals.
peroxisomes
96
highly reactive chemicals with unpaired electrons that can damage the structure of proteins and nucleic acids.
free radicals
97
true or false: free radicals are normal by-products of cellular metabolism, but if allowed to accumulatem, they will have devastating effects on cells.
true
98
peroxisomes convert free radicals into ________.
hydrogen peroxide
99
the enzyme ____________ converts excess hydrogen peroxide to water.
catalase
100
they replicate themselves by pinching half, like mitochondria. most ___________ appear to bud directly from the ER.
peroxisomes
101
an elaborate network of protein structures extends throughout the cytoplasm. cell's "bones and muscles" that serve as an internal framework that determines the cell shape, supports, and acts as machinery for intracellular transport.
cytoskeleton
102
the cytoskeleton is made up of:
microfilaments, intermediate filaments, and microtubules.
103
most involved in cell motility and in producing changes in cell shape
microfilaments
104
strong, stable, rope-like ____________ are made up of fibrous subunits. they help form demosomes and provide internal guy wires to resist pulling forces on cell.
intermediate filaments
105
are made up of repeating subunits of the protein tubulin. they determine the overall shape of a cell and distribution of organelles. important during cell division.
microtubules
106
lie close to the nucleus. these are rod-shaped bodies that lie at right angles to each other. their roles is to generate microtubles and directs the formation of mitotic spindle during cell division. made up of 9 triplets of fine microtubules.
centrioles (paired: centrosomes)
107
are whiplike cellular extensions that move substances along the cell surface.
cillia
108
projection that are substantially longer than cillia that has a single propulsive flagellum called its tail.
flagella
109
