Chapter 4: The Tour of a Cell Flashcards
(161 cards)
1
Q
Cells were discovered by
A
Robert Hooke in 1665
2
Q
Who proposed the cell theory?
A
Schleiden and Schwann
3
Q
Cells arise only from…
A
pre-existing cells
4
Q
all cells represent a…
A
a continuous line of descent from the first living cells
5
Q
limitation of cell size relies on the
A
diffusion of substances in and out of cells
6
Q
rate of diffusion is affected by…
A
- surface area available
- temperature
- concentration gradient
- distance
7
Q
as cell size _____ its volume _____ more rapidly than its _____ _____.
A
increases
increases
surface area
8
Q
How can an organism have an advantage over another organism?
A
by being made up of many small cells
9
Q
some cells overcome limitation by…
A
being long and skinny (ex: neurons)
10
Q
Structural similarities in cells are…
A
- nucleoid or nucleus
- cytoplasm
- ribosomes
- plasma membrane
11
Q
cytoplasm is a
A
semifluid matrix of organelles and cytosol
12
Q
ribosomes
A
synthesize proteins
13
Q
plasma membrane is a
A
selective phospholipid bilayer that allows passage of oxygen, nutrients, and waste products
14
Q
prokaryotic cells
A
- simplest organisms
- lack a membrane-bound nucleus
- cell wall outside of plasma membrane
- contain ribosomes
- no membrane-bound organelles
15
Q
The two sub-domains of prokaryotes are…
A
archaea and bacteria
16
Q
most bacterial cells have a ____ ____ ____ composed of _____.
A
strong cell wall
peptidoglycan
17
Q
cell walls….
A
- protects the cell
- maintains its shape
- prevents excessive uptake or loss of water
18
Q
archaea do NOT have
A
a cell wall
19
Q
susceptibility of bacteria to antibiotics depends on…
A
the structure of their cell walls
20
Q
Flagella is NOT an
A
organelle
21
Q
Flagella is a
A
naked thread of protein
22
Q
Flagella is present in
A
some prokaryotic cells; sometimes more than one is present
23
Q
A flagella is used for
A
locomotion
24
Q
eukaryotic cells are…
A
larger than protists
25
eukaryotic cells have...
1. internal membranes that compartmentalize their functions
2. membrane-bound nucleus
3. cytoskeleton
26
Most proteins are ____ which allows _____.
polar
membrane proteins to stay in membrane
27
eukaryotic cell's genetic material is carries out by
ribosomes
28
what is the nucleolus?
a region where ribosomal RNA synthesis takes place
29
the nuclear envelope is made up of...
- 2 phospholipid bilayers
| - nuclear pores
30
nuclear pores control
passage of molecules in and out
31
nuclear lamina...
- is made of strong cable-like proteins
| - holds shape; supporting structure
32
cytoplasmic filament
filters the products that enter nucleus
33
fully assembled ribosomes move to
the outside of the RER
34
DNA combines with proteins to form
chromatin
35
before cell division chromatin aggregates to form
chromosomes
36
ribosomes are cell's
protein synthesizing machines
37
ribosomes are found in...
all cell types in all three domains
38
ribosomal RNA (rRNA) is a
protein complex
39
protein synthesis also requires...
messenger RNA (mRNA) and transfer RNA (tRNA)
40
Ribosomes within the cell are found in
cytoplasm or associated w/ internal membranes
41
The endomembrane system...
regulates protein traffic and metabolic functions
42
the endomembrane consists of
- nuclear envelope
- endoplasmic reticulum
- Golgi apparatus
- lysosomes
- vacuoles (in plants)
- plasma membrane
43
vesicles..
fuse or connect endomembrane organelles via transfer; either directly or indirectly
44
What two organelles from the endomembrane system are NOT physically connected?
1. nuclear envelope
| 2. endoplasmic reticulum
45
the rough endoplasmic reticulum is...
physically connected to the smooth endoplasmic reticulum
46
the rough endoplasmic reticulum is..
physically connected to the smooth endoplasmic reticulum
47
Three characteristics of the endomembrane are...
1. its a series of membranes throughout the cytoplasm
2. it divides cell into compartments where different cellular functions occur
3. its a fundamental distinction between eukaryotes and prokaryotes
48
The endomembrane system is how...
traffic is coordinated
49
rough endoplasmic reticulum (RER) has ___ attached to its membrane?
ribosomes
50
the RER makes sure...
proteins are folded correctly
51
What synthesizes proteins?
ribosomes
52
in the RER proteins are secreted and sent to
lysosomes or the plasma membrane
53
the smooth endoplasmic reticulum is NOT where..
protein folding occurs
54
The SER functions are..
- lipid synthesis
- CA2+ storage
- detoxification
- carbohydrate metabolism
- making cell membrane for RER
55
the SER is a ____ ____ for ____, which is critical in reducing high _____ ______.
holding
tank
calcium
calcium concentration
56
The SER acting as a holding tank is critical in not having a...
high calcium concentration
57
the Golgi Apparatus is a...
flattened stack of interconnected membranes
58
golgi apparatus is made of the...
cis and trans faces
59
in the golgi apparatus cargo vessels travel to the...
cis face
60
functions of golgi apparatus is...
- clip pieces of proteins
- add sugars to proteins
- modify and sort molecules that are synthesized in one location and used at another
- uses vesicles to transport molecules to their destination
61
the golgi apparatus is known as the
"UPS" center
62
lysosomes are membrane-bound...
digestive enzymes
63
lysosomes arise from...
golgi and endosomes
64
lysosome's enzymes...
catalyze the breakdown of macromolecules transported into the cell
65
lysosomes function is to...
destroy cells or foreign matter that the cell has engulfed by phagocytosis
66
proteins are delivered to...
lysosomes
67
phagocytosis is when a...
lysosome is digesting food
68
autophagy is when a...
lysosome breaks down damaged organelles
69
autophagy is highly accelerated during...
physical activity, used as a energy source
70
Organelles outside the endomembrane include...
-peroxisomes
-vacuoles
-mitochondria
chloroplasts
71
peroxisomes contain...
enzymes involved in oxidation of fatty acids
72
What is produced as a byproduct of peroxisomes breaking down molecules?
H2O2 (hydrogen peroxide)
73
What is the enzyme that peroxisomes produce and what is its function?
enzyme: catalase
breaks down toxic materials making it harmless
74
description words for peroxisomes are...
- unusual
- metabolic organelles
- break down
75
vacuoles are...
membrane-bound structures in plants
76
vacuoles have various functions depending on..
the type of cell
77
vacuoles are formed by the..
endoplasmic reticulum
78
What are the three different types of vacuoles?
- central vacuole in plant cells
- contractile vacuole of some protists
- storage vacuoles
79
are vacuoles found in eukaryotic cells?
yes but very few
80
vacuoles are found in..
amoeba and some protists
81
mitochondria is found in...
all types of eukaryotic cells
82
mitochondria have their own..
DNA
83
mitochondria is the site of...
extracellular respiration (ATP production site)
84
ALL cells MUST have?
mitochondria
85
mitochondrial DNA is present in the ____ and comes from the _____.
egg
mother
86
mitochondria is the ONLY organelle in animal cells that have..
2 membranes
87
increased membrane leads to
increased energy
88
on the surface of the Cell and embedded within it are...
proteins that carry out oxidative metabolism
89
Chloroplasts are ONLY found in _____ and some _______ ___ and ____
plants
photosynthetic algae and bacteria
90
chloroplasts have their OWN
DNA
91
chloroplasts are found in
leaves, other green organs of plants and algae
92
chloroplasts have...
two membranes
93
chloroplasts expand to..
maximize photosynthesis
94
chloroplasts contain?
- chlorophyll
- enzymes
- other molecules that function in photosynthesis
95
Thylakoids are
membranous sacs within the inner membrane of chloroplasts
96
Grana are
stacks of thylakoids
97
Similarities between mitochondria and chloroplasts are?
- two membranes
- have their own DNA
- involved in energy transformation
- both support endosymbiosis theory
98
endosymbiosis states that..
one cell was engulfed by and became part of another cell, which was the precursor of modern eukaryotes
99
endosymbiosis proposes that...
some eukaryotic organelles evolved by a symbiosis arising between two cells that were each free-living
100
the cytoskeleton is a
extracellular matrix made of a network of fibers
101
the cytoskeleton organizes...
cell's structures and activities
102
the cytoskeleton anchors
many organelles
103
The cytoskeleton is composed of what three types of structures?
1. microtubules
2. microfilaments
3. intermediate filaments
104
microfilaments are two
intertwined actin filaments
105
microfilaments are the smallest
of the three cytoskeleton proteins
106
microfilaments are known as..
dynamic proteins
107
microfilaments are chains of
singular globular proteins
108
microfilaments form
cell surface projections
109
microfilaments movements include...
- contraction
- crawling
- "pinching"
110
intermediate filaments are the ____ of the cytoskeleton proteins
middle-sized
111
intermediate filaments are...
very stable and usually not broken down
112
intermediate filaments are important in the
skin and nervous system
113
intermediate filaments are known as _____ bc they form _____ _____ _____.
"cellular glue"
strong cellular connections
114
intermediate filaments are not composed of
a string of beads
115
intermediate filaments are found in the
skin and organs; giving it elasticity
116
intermediate filaments are composed of
several different proteins
117
microfilaments are about ____ long.
7 nm
118
intermediate filaments are between _____ long.
8-12 nm
119
microfilaments are important in changes in cell shape when it comes to
division of animal cells
120
intermediate filaments are important to the
- anchorage of the nucleus and other organelles
| - formation of nuclear lamina
121
microtubules are the ___ of the cytoskeleton elements
largest
122
microtubules form
hollow cylinders
123
microtubules are made of
alpha and beta tubulin subunits
124
microtubules facilitate movement of
cell and materials within cell
125
microtubules are important in
- cell division
- cell movement
- delivery of cargo vessels
126
microtubules are between ____ long.
25 w/ 15 nm lumen
127
microfilaments and intermediate filaments maintain cell shape bc they are?
tension-bearing elements
128
microtubules maintain cell shape bc they are?
compression-resisting elements
129
microtubules facilitate cell motility by..
- chromosomal movements in cell division
| - organelle movement
130
centrioles are a
pair of cylindrical organelles
131
centrioles are found in...
animal cells and most protists
132
centrioles are absent in..
plants and fungi
133
centrioles are oriented
perpendicular to one another
134
two centrioles oriented perpendicular to each other compose a
centrosome
135
centrosomes is the
region surrounding centrioles in almost ALL animal cells
136
centrosomes are known as the
microtubule-organizing center
| can begin the assembly of microtubles
137
centrosomes are involved in the..
mitotic spindle
138
cell movement is possible by the movement of ____ _____ , __________, or both.
actin filaments
microtubules
139
some cells crawl using..
actin microfilaments
140
eukaryotic protists use _____ and ____ for movement.
flagella
cilia
(not like prokaryotic flagella)
141
cilia in eukaryotic protists are..
shorter and more numerous
142
flagella is made from
microtubules
143
an example of a eukaryotic cell that uses flagella and cilia for cell movement is?
sperm cells
144
what causes cilia to bend?
sliding microtubules that extend into the basal body (identical to centrioles) in the cytoplasm
145
cell walls are composed of...
cellulose and chitin
146
eukaryotic cells walls are found in...
plants, fungi, and other protists
147
eukaryotic cell walls are...
different from prokaryotes
148
plants and protists have a cell wall composed of...
cellulose
149
fungi have a cell wall composed of...
chitin
150
the extracellular matrix (ECM)
- forms a protective layer
| - integrins link matrix to the inner cytoskeleton
151
collagen and elastin are abundant in the
ECM
152
animal cells DO NOT have a
cell wall
153
cells secrete ________ into the external space
glycoproteins
154
collagen and elastin are
intermediate filaments that keep region hydrated
155
the ECM is a barrier for
bacterial invasions
156
The ECM has sugars bonded to the proteins..where did this happen?
in the ER
157
What are the three types of cell connections?
1. tight junction
2. anchoring junction
3. communicating junctions
158
a tight junction...
connects the plasma membranes of adjacent cells in a sheet
no leakage
159
anchoring junctions mechanically
attaches cytoskeletons of neighboring cells (desmosomes)
160
anchoring junctions leave more room for....
hydration and elasticity
161
communicating junctions have...
chemical or electrical signals passing directly from one cell to an adjacent one
(gap junction, plasmodesmata)
