Chapter 4 (Exam Two) Flashcards
1
Q
The cellular level of organization. A detailed study of the cell in what year? This is a (blank) concept in biology
A
1830’s; unifying
2
Q
Detailed studies of the cell originated from the works of biologists (blank) and (blank) in what years?
A
Schleiden and Schwann in 1838-1839
3
Q
In the cell theory, what two scientists came up the concept that organisms are composed of cells? (country, type of scientist)
A
German botanist; Matthias Schneiden
German zoologist Theodor Schwann
4
Q
In the cell theory, what scientist came up with the concept all cells come only from preexisting cells because
cells are self-reproducing? (country, type of scientist)
A
German physician Rudolph Virchow
5
Q
Cells range in size from what to what in diameter?
A
one millimeter (mm) down to one micrometer (μm) in diameter.
6
Q
Cells need a large surface area of plasma membrane to
A
to adequately exchange materials.
7
Q
What does the surface-area-to-volume ratio require?
A
that cells be small
8
Q
What is the surface-area-to-volume ratio in large cells?
A
surface area relative to volume decreases which also decreases the efficiency of transporting materials in and out of the cell
9
Q
What is the surface-area-to-volume ratio in small cells?
A
Small cells – larger surface-area-to-volume ratio is advantageous for exchanging molecules
10
Q
How do we see through a compound light microscope?
A
Light is passed through the specimen. Then it is focused by a series of glass lenses. It forms an image on the human retina.
11
Q
In a compound light microscope, the maximum magnification is about
A
1000X
12
Q
The compound light microscope resolves objects separated by (blank) μm,. How much better is this than the human eye?
A
0.2, 500X better than the human eye (Assuming the resolving power of the human eye is 1.0)
13
Q
How do we see through a Transmission Electron Microscope? (3 steps)
A
- Electrons are passed through specimen and then they are focused by a set of magnetic lenses.
- An image is formed on a fluorescent screen similar
to a TV screen. - The image is then photographed.
14
Q
What provides greater magnification, a compound light microscope or a TEM microscope?
A
TEM
15
Q
TEM microscope resolves objects separated by (blank) μm,. How much better is this than the human eye?
A
0.0002, 100,000X better than human eye.
16
Q
How do we see through a Scanning Electron Microscope? 6 steps
A
- The specimen is sprayed with a thin coat of metal.
- Then an electron beam is scanned across the surface of the specimen.
- The surface metal emits secondary electrons.
- The emitted electrons are detected and focused by magnetic lenses.
- A 3-dimensional image is formed on a fluorescent screen similar to a TV screen.
- Image is then photographed
17
Q
Magnification is the ratio between?
A
the size of an image and its actual size.
18
Q
Resolution in a microscope?
A
the minimum distance between two objects that allows them to be seen as two separate objects.
19
Q
Contrast in a microscope?
A
the difference in shading of an object compared to its background.
20
Q
(blank) can be bent (refracted) and focused as they pass through glass, but (blank) can’t
A
light rays; electrons
21
Q
How are electrons seen through the glass in a microscope? 2 steps
A
- Electrons have a charge and can be focused by
electromagnetic lenses. - The electrons leaving the specimen are then directed to a screen or photographic plate, which is sensitive to electrons which can be viewed by humans.
22
Q
How does confocal microscopy work? 5 steps
A
- A narrow laser beam is scanned across a transparent specimen.
- The beam is focused on one very thin plane in the
cell. - A microscopist can “optically section” a specimen by
focusing up and down. - Sections are made at different levels.
- This allows assembly of a 3-dimensional electronic image on a computer screen that can be displayed and rotated on the screen.
23
Q
How does Video-Enhanced Contrast Microscopy work? 4 steps
A
- The microscope image can be recorded by a TV
camera. - In video-enhanced contrast microscopy, a TV camera converts the light image into an electronic image, which is entered into computer.
- The computer makes the darkest areas of the image darker and the lightest areas lighter.
- The result is a high-contrast image which can be manipulated further for greater contrast.
24
Q
Prokaryotic lack a what?
A
membrane bound nucleus
25
Prokaryotic cells are what compared to eukaryotic?
smaller and simpler
26
Prokaryotic cells are placed in what two taxonomic
| domains?
Bacteria and Archaea
27
What do prokaryotic cells in Domain Bacteria do?
Cause diseases but are also environmentally important as
decomposers
Can be useful in manufacturing products and drugs
28
What do prokaryotic cells in Domain Archaea do?
live in extreme habitats
29
How are two prokaryotic domains similar different?
structurally similar but biochemically different
30
A prokaryotic cell can come in what 3 basic shapes?
Spherical coccus
Rod-shaped bacillus
Spiral spirillum (if rigid) or spirochete (if flexible)
31
The cell envelope in a prokaryotic cell includes what 3 stuctures?
plasma membrane, cell wall, glycocalyx
32
The plasma membrane in the cell envelope in the prokaryotic cell is what?
lipid bilayer with embedded and peripheral proteins
| Can form internal pouches (mesosomes), which increase surface area
33
The cell wall in the cell envelope of a prokaryotic cell is what?
maintains the shape of the cell and is strengthened by
| peptidoglycan
34
The glycocalyx in the cell envelope of a prokaryotic cell is what?
layer of polysaccharides on the outside of the cell wall
| Well organized and resistant to removal (capsule)
35
Name prokaryotic cytoplasm (4) and external structures (3)
Cytoplasm, Nucleoids, Plasmids, Ribosomes
| External structure: flagella, fimbriae, conjugation pili
36
Describe cytoplasm in a prokaryotic cell
Semifluid solution
Encased by plasma membrane
Contains water, inorganic and organic molecules, and enzymes
37
Describe nucleoids in a prokaryotic cell
a region that contains the single, circular DNA molecule.
38
Describe plasmids in a prokaryotic cell
small accessory (extrachromosomal) rings of DNA.
39
Describe ribosomes in a prokaryotic cell
tiny structures in the cytoplasm that synthesize proteins.
40
Describe flagella on a prokaryotic cell
they provide motility
41
Describe fimbriae on a prokaryotic cell
small, bristle-like fibers that sprout from the cell surface
42
Describe conjugation pili on a prokaryotic cell
rigid tubular structures used to pass DNA from cell to cell (singular pilius)
43
Eukaryotic cells contain what? What distinguishes it from a prokaryotic cell?
Membrane-bound nucleus that houses DNA
Specialized organelles
Plasma membrane
The first two distinguish eukaryotic from prokaryotic cells
44
What does the plasma membrane do in a eukaryotic cell? (3)
separates cell contents from environment
regulates passage of materials in and out
is composed of a phospholipid bilayer with embedded proteins
45
Eukaryotic cells are compartmentalized. What does this mean?
Eukaryotic cells are compartmentalized.
They contain small structures called organelles which perform specific functions and isolate reactions from other reactions
46
The fossil record suggest that the first cells were
prokaryotes.
47
Biochemical data shows eukaryotes are more closely related to what than what?
archaea than bacteria.
48
The nucleus is believed to have evolved by
invagination of the plasma membrane.
49
The invagination process also explains origins of what two things?
endoplasmic reticulum and Golgi.
50
Energy organelles, mitochondria and chloroplasts, may
| have originated when. What is this theory called?
a eukaryotic cell engulfed smaller prokaryotic cells. Eukaryotic cell would have benefitted the from ability to utilize oxygen or synthesize organic food.
Endosymbiotic theory
51
two classes of organelles?
Endomembrane system and Energy-related organelles
52
What type of organelles are in the endomembrane system?
Organelles that communicate with one another
Via membrane channels
Via small vesicles
53
What type of organelles are in the energy-related organelles?
Mitochondria and chloroplasts
| Independent and self-sufficient
54
The cell is a system of interconnected (blank) that work together.
organelles
55
Production of specific molecules takes place in or
| on organelles by
enzymes in membranes
56
Products are transported around cell by
vesicles
57
What are vesicles?
Sacs made of membrane material
58
Vesicles move around using
cytoskeletal network.
59
Plant cells, fungi, and many protists have this organelle
cell wall
60
Plant cell walls contain
cellulose, a structural polysaccharide
61
The nucleus is the
command center of cell, usually near center
62
The nucleus is separated from cytoplasm by
nuclear envelope
63
The nuclear envelope consists of
double layer of membrane
64
in the nuclear envelope, (blank) permit exchange between nucleoplasm and cytoplasm
nuclear pores
65
The nucleus contains (blank) in semifluid (blank)
chromatin; nucleoplasm
66
Chromatin contains (2)
proteins and nucleic acids
67
chromatin condenses to form
chromosomes
68
chromosomes are formed during (blank) and are carriers of (blank)
cell division; genetic information
69
The nucleus has a dark nucleolus composed of
rRNA
70
Ribosomes are composed of
rRNA
71
rRNA consist of
a large subunit and a small subunit.
| Subunits are made in nucleolus.
72
Ribosomes may be located:
on the endoplasmic reticulum (thereby making it “rough”), or free in the cytoplasm, either singly or in groups, called polyribosomes.
73
Ribosomes are the site of
protein synthesis in the cell
74
In the process of transcription and translation information for the gene is copied into (blank) which is exported into the (blank)
mRNA; cytoplasm
75
(blank) receive the mRNA with a coded message from DNA with the correct sequence of amino acids to make a protein.
ribosomes
76
proteins synthesized by cytoplasmic ribosomes stay in (blank) ; those by attached ribosomes end up in (blank)
cytoplasm; ER
77
The central dogma of molecular biology is
the DNA-mRNA-protein sequence of events
78
The Endomembrane System is a series of
intracellular membranes that compartmentalize the cell
79
The Endomembrane System restrict
enzymatic reactions to specific compartments within cell
80
The Endomembrane System consists of (4)
Nuclear envelope
Membranes of endoplasmic reticulum
Golgi apparatus
Vesicles
81
The Endoplasmic Reticulum is a system of
membrane channels and saccules (flattened vesicles) continuous with the outer membrane of the nuclear envelope
82
The Rough ER is studded with
ribosomes on cytoplasmic side
83
The Rough ER is the site of (blank) which what?
Protein anabolism
84
Protein anabolism synthesizes, modifies and processes (blank)
Adds (blank) to proteins
Results in (blank)
proteins; sugar; glycoproteins
85
The Rough ER forms
transport vesicles
86
the Smooth ER has no
ribosomes
87
The Smooth ER contains the synthesis of
lipids
88
The Smooth ER is the site of
arious synthetic processes, detoxification, and storage
89
Like the Rough ER, the Smooth ER forms
transport vesicles
90
The Golgi Apparatus is named for
Camillo Golgi
91
The Golgi Apparatus consists of
flattened, curved saccules
92
The Golgi Apparatus modifies (blank) and (blank) with what?
proteins and lipids with “signal” sequences
93
The Golgi Apparatus receives (blank) from what?
vesicles from ER on cis (or inner) face
94
After modification, the Golgi Apparatus prepares for “shipment” and packages (blank) in (blank) that leave Golgi from (blank) (or outer) face
proteins and lipids; vesicles; trans
95
After modification, prepares for “shipment” and packages proteins and lipids in vesicles that leave Golgi from trans (or outer) face. What happens to them? (3)
Some transported to locations within cell
Some exported from cell (secretion, exocytosis)
Others returned to ER or merged with plasma membrane
96
Lysosomes are not found in
plants
97
Lysosomes are (blank) vesicles
membrane-bound
98
Lysosomes are produced by
the Golgi apparatus
99
Lysosomes contain (blank) that are highly (blank)
digestive enzymes ; acidic
100
Lysosomes digest (blank) into (blank)
large molecules into simpler subunits
101
lysosomes recycle
cellular resources
102
Lysosomes, In white blood cells
engulf pathogens
103
Lysosomal storage diseases are caused by (blank)
| example
defect in lysosomal enzyme
| Tay-Sachs
104
Endomembrane System: (blank) produced in rough ER and (blank) from smooth ER are carried in (blank) to the (blank) which modifies these products and then sorts and packages them into vesicles that go to various cell destinations. (blank) vesicles carry products to the membrane where (blank) produces secretions. (blank) fuse with incoming vesicles and digest (blank)
proteins; lipids; vesicles; Golgi Apparatus; secretory; exocytosis. Lysosomes; macromolecules
105
(blank) contain specialized enzymes to perform special metabolic functions. Example?
microbodies; peroxisomes
106
Peroxisomes are similar to
lysosomes
107
peroxisomes are (blank) vesicles
membrane-bound
108
Peroxisomes enclose
enzymes
109
Lack of peroxisomal membrane protein results in
ALD
110
Peroxisomes are active in
lipid metabolism
111
Peroxisomes catalyze reactions that produce (blank) which is broken down to water and oxygen by (blank)
hydrogen peroxide; catalase
112
What are vacuoles?
Membranous sacs that are larger than vesicles
113
Vacuoles (blank) materials that occur in excess
store
114
Plants cells typically have a (blank) vacuole
central
115
The central vacuole functions in the storage of what? (4)
water, nutrients, pigments, and waste products
116
Central vacuole functions in the development of
turgor pressure
117
Central vacuole functions in (blank) used for protection by some herbivores
toxic substances
118
Central vacuoles perform some functions normally done by (blank) for other eukaryotes
lysosomes
119
Chloroplasts are bounded by a
double membrane
120
In Chloroplasts, the inner membrane is
infolded
121
The inner membrane in chloroplasts form disc-like (blank) which are stacked to form (blank). It is suspended in semi-fluid (blank)
thylakoids, grana, stroma
122
The chloroplast is green due to
chlorophyll
123
what is chlorophyll? where is it?
Green photosynthetic pigment; Found ONLY in inner membranes of chloroplast
124
Chloroplasts are a type of
plastid
125
Chloroplasts serve as the site of
photosynthesis
126
Chloroplasts captures (blank) to drive cellular machinery
light energy
127
In photosynthesis, synthesizes (blank) from (blank)
carbohydrates from carbon dioxide and water
128
In photosynthesis, food is made using
carbon dioxide
129
formula for photosynthesis (words)
solar energy + carbon dioxide + water ---> carbohydrate + oxygen
130
chlorophyll is located in the (blank)
thylakoid membrane
131
enzymes that synthesize carbohydrates in photosynthesis are located in the
fluid stroma
132
Only (blank) are capable of conducting photosynthesis
plants, algae, and certain bacteria
133
(blank) theory describes eukaryotic cell engulfing photosynthetic (blank)
Endosymbiotic; bacterium
134
Contained by nearly all eukaryotic cells and all plant, algae, and animal cells
Smaller than chloroplast
mitochondria
135
Numbers of mitochondria vary with
metabolic activities and energy requirements of cells
136
Mitochondria contain (blank) (2)
ribosomes; dna
137
Mitochondria are surrounded by a
double membrane.
138
Inner membrane of a mitochondria surrounds the (blank) and is convoluted (folded) to form (blank)
matrix; cristae
139
What is a matrix?
Inner semifluid substance containing respiratory enzymes
140
The matrix breaks down
carbohydrates
141
How is the mitochondria involved in cellular respiration
oxygen used and carbon dioxide given off
142
Mitochondria produce most of the (blank) utilized by the cell
ATP
143
The cytoskeleton maintains
cell shape
144
The cytoskeleton assists in
movement of cell and organelles
145
the cytoskeleton makes (blank) possible
internal transport
146
Three types of macromolecular fibers in cytoskeleton
Actin filaments
Intermediate filaments
Microtubules
147
Assemble and disassemble as needed
cytoskeleton
148
how does the cytoskeleton compare to bones and muscle of animal
Is dynamic; responds to environmental changes
149
Extremely thin filaments, like pearl necklace
actin filaments
150
Actin filament is a dense web just under (blank) maintains (blank)
plasma membrane; cell shape
151
Actin filaments provide support for (blank) in intestinal cells
microvilli
152
What do actin filaments do in intracellular traffic control?
For moving stuff around within cell
| Cytoplasmic streaming
153
Actin filaments function in (blank) of amoeboid cells
pseudopods
154
Actin filaments are important components in (2)
muscle contraction and animal cell division
155
Intermediate in size between actin filaments and microtubules
intermediate filaments
156
intermediate filaments are a rope-like assembly of
fibrous polypeptides
157
Intermediate filaments support
nuclear envelope
158
intermediate filaments function in (blank) junctions
cell-cell
159
Protein (blank) provides mechanical strength to skin cells
keratin
160
Hollow cylinders made of two globular proteins called α and β tubulin
microtubules
161
in microtubules, Spontaneous pairings of α and β tubulin molecules form structures called (blank) which then arrange themselves into tubular spirals of 13 dimers around
dimers
162
Assembly of microtubules is under control of
Microtubule Organizing Center (MTOC)
163
Most important MTOC is
centrosome
164
Microtubules interact with “motor” molecules (blank and blank) to cause movement of organelles
kinesin and dynein
165
(blank) distributes chromosomes during cell division
Mitotic “spindle”
166
Short, hollow cylinders
Composed of 27 microtubules
Microtubules arranged into 9 overlapping triplets
centrioles
167
how many centrioles are in an animal cell
one per animal cell
168
where are centrioles located
Located in centrosome of animal cells only
169
Centrioles are located at (blank) to each other
right angles
170
Centrioles separate during (blank) to determine plane of d(blank)
mitosis; divison
171
Centrioles may give rise to basal bodies of
cilia and flagella
