Bio 110 Chapter 4 Flashcards
1
Q
cells are the simplest collection of
A
matter that can live.
2
Q
cells were first observed by
A
Robert Hooke in 1665 in cork.
3
Q
Antoni van Leeuwenhoek
A
worked with more refined lenses and later described blood, sperm, and organisms in pond water.
4
Q
The cell theory states
A
all living things are composed of cells, and all cells come from other cells.
5
Q
Cell size must be large enough to
A
house DNA, proteins and structures needed to survive, but small enough to allow for a surface to volume ratio that will allow adequate exchange with the environment.
6
Q
light microscope (LM)
A
most commonly used
light passes through a specimen, then through glass lenses, and then to the viewer’s eye.
7
Q
With a light microscope specimens can be magnified up to
A
1,000 times the actual size of the specimen.
8
Q
magnification
A
to increase the apparent size of an object
9
Q
resolution
A
a measure of the clarity of an image. (the ability to show 2 close objects as separate)
10
Q
since the human eye and the microscope have limits on resolution (the ability to distinguish between small objects),
A
light microscopes cannot provide the details of a small cell’s structure.
11
Q
using light microscopes, scientists studied
A
microorganisms, animal and plant cells, and some structures within the cells.
12
Q
In the 1950’s scientists started using a powerful microscope to view the ultrastructure of cells called the
A
Electron microscope (EM)
13
Q
Electron microscopes can
A
resolve biological structures as small as 2nm
14
Q
with an EM specimens can be magnified up to
A
100,000 times.`
15
Q
most cells are between
A
1 and 100 micrometers (um) in diameter.
16
Q
LMs can’t resolve detail finer than
A
about 0.2 micrometers (um)
17
Q
Instead of light EM uses
A
a beam of electrons.
18
Q
the EM has a
A
100-fold improvement over the light microscope in resolution.
19
Q
Scanning electron microscopes (SEM) study
A
the detailed architecture of cell surfaces.
20
Q
Using SEM the sample is
A
coated in gold and an electron beam excites surface electrons, and these electrons are detected by a device that translates their pattern to a video screen.
21
Q
Transmission Electron microscopes (TEM) study
A
the details of internal cell structure.
22
Q
The TEM aims
A
electron beam through a thin section of the specimen with is stained with heavy metal atoms, binding more in some places than others.
23
Q
TEM lenses are
A
electromagnets.
24
Q
Electron microscopes can’t be used to study
A
living specimens, because the ways to prepare the samples kill the cells.
25
Differential interference light microscopes
amplify differences in density so that structure of living cells appear almost 3D
26
fluorescent microscopy
a type of light microscopy.
27
Bacteria and archaea are
prokaryotic cells
28
prokaryotic and eukaryotic cells have in common
```
a plasma membrane
one of more chromosomes
ribosomes
DNA
cytoplasm
```
29
Chromosomes carry
genes made of DNA
30
Ribosomes make
proteins according to gene instructions
31
all the material inside the plasma membrane and outside the DNA containing region
cytoplasm
32
the fluid portion of the cytoplasm is made of
water, salts, and organic molecules
33
Eukaryotic cells have (prokaryotic cells don't)
membrane-bound nucleus
| number of other organelles
34
Prokaryotic cells have (eukaryotic cells don't)
```
nucleoid
no true organelles
smaller and slightly different ribosomes
cell wall and plasma membrane
capsule/slime layer
pili/fimbriae (some)
flagella
```
35
the cell wall and plasma membrane maintain
call shape and protection
36
capsule
sticky outer coat around the cell wall of some prokaryotic cells, helping to glue it to surfaces.
37
flagella
propel prokaryotic cells though its liquid environment.
38
organelles
little organs, perform specific functions of the cell. Each organelle is bounded by a membrane with a lipid and protein composition that suits its function.
39
four basic functions of organelles and structures in a cell:
NUCLEUS and ribosomes are involved in genetic control of the the cell
ER, golgi, lysosomes, vacuoles and peroxisomes manufacture distribute and breakdown molecules
MITOCHONDRIA in all cells and chloroplasts in plants cells are involved in energy processing.
CYTOSKELETON plasma membrane and cell wall function as structural support, movement and communication between cells.
40
The internal membranes of eukaryotic cells
partition it into compartments.
41
cellular metabolism
occurs withing organelles
42
Present in animal cells, but not in plant cells are:
lysosomes and centrioles
43
present in plant cells but not in animal cells
cell wall (cellulose)
chloroplasts (photosynthesis)
central vacuole
plasmodesma (plasmodesmata)
44
plasma membrane
forms a flexible boundary between the living cell and it's surroundings
45
phospholipids form a 2 layer sheet
called the phospholipid bilayer.
46
membrane proteins are either
attached to the membrane surface or embedded into the phospholipid bilayer.
47
phospholipid bilayer is the main component of
cell membranes
48
some proteins form channels or tunnels that
shield ions and other hydrophilic molecules as they pass through the hydrophobic center of the membrane.
49
some proteins serve as
pumps, using energy to actively transport molecules into or out of the cell.
50
membranes are composed of:
a bilayer of phospholipids with embedded and attached proteins in a structure called a fluid mosaic.
51
plasmodesmata
cytoplasmic channels through cell walls that connect adjacent cells
52
central vacuole
a compartment that stores water and a variety of chemicals.
53
The nucleus
contains most of the cell's DNA and controls the cells activities by directing protein synthesis by making mRNA.
54
DNA is associated with many proteins in structures called
chromosomes
55
Proteins help
organize and coil the DNA to fit into the nucleus
56
DNA + proteins in non-dividing cell
is chromatin
57
upon division DNA + protein
thicken and form "tubes" known as chromosomes
58
the nuclear envelope is a
double membrane of separate phospholipid bilayers that encloses the nucleus
59
the nuclear envelope has
pores that allow material to flow in and out of the nucleus
60
the nuclear envelope is attached to a network of
cellular membranes called the ER.
61
the nucleolus is
a prominent structure in the nucleus and the site of ribosomal RNA synthesis, and directs protein synthesis by making mRNA.
62
rRNA is synthesized according to
instructions in the DNA. assembled with proteins to from ribosome subunits, then exit into cytoplasm where they join to form functional ribosomes.
63
Ribosomes are involved in
the cell's protein synthesis
64
cells that must synthesize large amounts of proteins have
a large number of ribosomes
65
2 locations of ribosomes
free ribosomes while others are bound
66
free ribosomes are
suspended in cytoplasm and involved in making proteins that function within the cytoplasm.
67
bound ribosomes are
attached to the ER and associated with proteins packed in certain organelles or exported from the cell
68
free and bound ribosomes are
structurally identical and can alternate places.
69
the endomembrane system is
unique to eukaryotic cells
70
some of the membranes in the endomembrane system are
physically connected and some are related by the transfer of membrane segments by tiny vesicles (sacs made of membrane)
71
the endomembrane system includes
nuclear envelope, ER, golgi apparatus, lysosomes, vacuoles, and the plasma membrane (indirectly)
72
many organelles in the endomembrane system work together in
the synthesis, distribution, storage and export of molecules
73
Smooth ER
lacks attached ribosomes
74
Rough ER
has ribosomes attached and lines the outer surface of membranes
75
Although Smooth ER and rough ER are physically interconnected,
they differ in structure and function
76
Smooth ER is involved in
a variety of diverse metabolic processes
- produces enzymes important to the synthesis of lipids oils, phospholipids, and steroids
- enzymes in the smooth ER help process harmful substances
- stores calcium ions for muscle contraction
77
rough ER makes
more membrane for itself, then creates vesicles and transfers portions of itself
produce proteins that will be inserted into the growing ER membrane, transported to other organelles or secreted by the cell.
78
Discovered the golgi apparatus
Camillo Golgi
79
the golgi apparatus serves as a
molecular warehouse and finishing factory for products manufactured by the ER
80
The golgi apparatus isn't
connected to the ER
81
the number of stacks of a golgi
correlates with how active the cell is in protein secretion.
82
products travel in transport vesicles from the
ER to the golgi apparatus
83
one side of the golgi functions as a
receiving dock and the other as the shipping dock.
84
products are modified as they go from one side
of the golgi to the other
85
a membranous sac containing digestive enzymes
lysosome
86
the enzymes and membranes of lysosomes are made by
rough ER and processed in the golgi apparatus
87
the membrane of a lysosome serves
to safely isolate potent enzymes from the rest of the cell
88
lysosomes help digest food particles engulfed by a cell in that
a food vacuole binds with a lysosome
the enzymes in the lysosome digest the food
the nutrients are then released into the cell
89
lysosomes help remove or recycle damaged parts of a cell by
the damaged organelle is first enclosed in a membrane vesicle
then a lysosome fuses with the vesicle
dismantles it's contents
and breaks down the damaged organelle.
90
large vesicles that have a variety of functions
vacuoles
91
some protists have contractile vacuoles that help
to eliminate water from protists
92
in plants, vacuoles may
have digestive functions
contain pigments
contain poison that protect the plant.
93
peroxisomes
metabolic compartments that do not originate form the endomembrane system. Some break down fatty acids and detoxify harmful compounds.
94
organelles that carry out cellular respiration in nearly all eukaryotic cells
mitochondria
95
cellular respiration converts the chemical energy in foods to
chemical energy in ATP (adenosine triphosphate)
96
ATP
main E source for cellular work
97
two internal compartments of mitochondria
```
intermembrane space (narrow region between the inner & outer membranes)
mitochondrial matrix (enclosed by inner membrane)
```
98
cristae
increase surface area.
99
the mitochondrial matrix includes
cristae,
embedded proteins (that function in ATP synthesis)
mitochondrial DNA
Ribosomes
enzymes that catalyze some of the reactions of cellular respiration.
100
photosynthesizing organelles of all photosynthetic eukaryotes
chloroplasts
101
the conversion of light energy from the sun to chemical energy of sugar molecules.
photosynthesis.
102
chloroplasts have an
inner and outer membrane, between which is an intermembrane space
103
inside the inner membrane of a chloroplast is
stroma
thylakoids
granum
104
stroma is
thick fluid that contains chloroplast DNA, ribosomes, and enzymes.
105
thylakoids
interconnected sacs in a chloroplast
106
granum
a stack of thylakoids, where chlorophyll molecules trap solar energy
107
mitochondria and chloroplasts have
DNA and ribosomes
108
endosymbiont theory
mitochondria and chloroplasts were formerly small prokaryotes and they began living within larger cells.
109
cells contain a network of protein fibers which function in structural support and motility called
cytoskeleton
110
motility and cellular regulation result when the
cytoskeleton interacts with proteins called motor proteins
111
3 kinds of fibers in the cytoskeleton
microfiliments
intermediate filaments
microtubules
112
microfilaments
actin filaments that support the cell's shape and are involved in motility; thinnest filaments;arranged in twisted double chain
myosin and muscle contraction or amoeboid movement
113
intermediate filaments
reinforce cell shape and anchor organelles; various fibrous proteins supercoiled into thicker cables.
more permanent cell fixtures
114
microtubules
made of tublin, give the cell rigidity and act as tracks for organelle movement; thickest filaments; straight hollow tubes shape and support the cell
In Cilia and flagella
115
important in locomotion in some protists
flagella and cilia
116
multicellular organisms have flagella and cilia in
cells that sweep mucus out of lungs, or sperm
117
flagellum
longer that cilia, propels a cell by a whiplike motion.
118
cilia
work like oars of a crew boat
119
flagella and cilia have a common
structure and mechanism of movement
120
both flagella and cilia are made of
microtubules wrapped in and extension of the plasma membrane
121
9 + 2 pattern
a ring of 9 microtubule doublets surrounds a central pair of microtubules
122
a basal body
anchors the 9 + 2 pattern; nine microtubule triplets arranged in a ring
123
cilia and flagella move by
bending motor proteins called dynein feet
124
dynein proteins are
attached to an adjacent doublet and exert a sliding force attaching and reattaching (walking) causing microtubules to bend
125
in developed countries over the last 50 years,
sperm quality has declined
126
causes of sperm decline may be
environmental chemicals or genetic disorders that interfere with the movement of sperm
127
PCD
primary cilary dyskinesia; a rare disease that causes recurrent infections of the respiratory tract and immobile sperm
128
Animal cells synthesize and secrete an elaborate
extracellular matrix (ECM)
129
ECM (function)
helps hold cells together in tissues and protects and supports the plasma membrane.
130
The ECM may attach to a cell through
glycoproteins that then bind to integrins
131
integrins
membrane proteins that span the plasma membrane and connect to microfilaments of the cytoskeleton.
132
most abundant glycoprotein is
collagen
133
3 types of cell junctions found in animal tissues
tight junctions
anchoring junctions (desmosomes)
gap junctions
134
through specialized junctions between adjacent cells, cells can
communicate, interact, and adhere.
135
tight junctions
prevent leakage of extracellular fluid across a layer of epithelial cells
136
anchoring junctions
fasten cells together in sheets. (heart muscle and skin)
137
gap junctions
channels that allow molecules to flow between cells. (communication junctions)
138
cell wall
only in plants; protects and provides skeletal support, keeps plant upright against gravity; composed primarily of cellulose
