CELL BIOCHEMISTRY Flashcards
(133 cards)
1
Q
smallest unit that is capable of performing life functions
A
cell
2
Q
cell theory states that:
A
All living things are made up of cells.
- All cells come from pre-existing cells through
cell division
2
Q
basic types of cells (2)
A
prokaryotes
eukaryotes
2
Q
cells without a nucleus or membranebound organelles.
- Includes bacteria and archaebacteria
A
prokaryotes
3
Q
cells with nucleus and membrane-bound
organelles.
- Includes cells from plants, animals, fungi, and
protists
A
eukaryotes
4
Q
common cellular structures of prokaryotes
A
plasma membrane
cytoplasm
ribosomes
nucleoid
5
Q
The genetic material in bacteria
A
nucleoid
6
Q
genophore
A
bacterial DNA
7
Q
irregular aggregate of genophore or
bacterial DNA and nucleoid-associated proteins
A
nucleoid
8
Q
___ is made-up of circular, doublestranded piece of DNA.
A
bacterial DNA
9
Q
small circular,
double-stranded DNA that is physically separate from
the nucleoid
A
plasmids
10
Q
replicated independently of
the genophore and may contain genes that enhance the survival of bacteria such as antibiotic resistance genes
A
plasmids
11
Q
bacterial cell wall is made up of
A
peptidoglycan
12
Q
these are polysaccharides and protein aggregates
A
peptidoglycan
13
Q
made-up of phospholipid
bilayer with embedded proteins which delineates and protects the cell as well as regulating the passage of materials into and out of the cell
A
plasma membrane
14
Q
large polysaccharide structure that forms the outermost envelope and contains water which prevents the bacteria from drying out. It may also serve as protection from phagocytosis or being eaten by immune cell
thereby increasing the virulence or disease-causing ability of such bacteria
A
capsule
15
Q
Many bacteria have _____ which helps in environmental interaction such as pili, fimbriae,
and flagellum
A
proteinaceous appendages
16
Q
hair-like in appearance and utilized for surface
attachment or DNA exchange of DNA with another bacterium
A
pili
17
Q
also hair-like but are
shorter and more numerous
A
fimbriae
18
Q
whip-like structure
that can propel a bacterium for movement.
A
flagellum
19
Q
chromosomes in prokaryotes are usually ___ rather than linear
A
circular
20
Q
bacteria reproduce through ___
A
binary fission
21
Q
larger cells five times the size of a prokaryotic cell with an average size of about 50
micrometers
A
eukaryotic cells
22
Q
have membrane-bound nucleus and other
membrane-bound organelles unlike prokaryotic cells
A
eukaryotes
23
Plant cells are unique from animal cells due to the presence of ____ and __ cell wall.
chloroplast
cellulosic
24
Fungi cells also have cell walls but are made up of ___
chitin
25
N-acetylated form of cellulose
chitin
26
made up of cellulose, a
homopolysaccharide of the simple sugar glucose
cell wall
27
plant's cell wall which is made up of ____ that are
cross-linked with ___
cellulose microfibrils
pectin
28
pectin is a heteropolysaccharide of the sugars ____ and ____
galactose
galacturonic acid
29
has gel-like characteristics which binds the cellulose microfibrils together.
pectin
30
During ___, the cell membrane loses water and
its contents shrink up into a ball, while the outer cell
wall remains intact
plasmolysis
31
Shrubs and trees have a thickened secondary cell wall
which contains ___
lignin
32
a brown phenolic polymer that
imparts great strength and hardness to wood
lignin
33
provides structural support to plant cells and prevents the plant cells from bursting under high
turgor pressure
cell wall
34
who cretted the fluid mosaic model
singer
nicolson
35
describes the structure of the
plasma membrane as composed of a phospholipid bilayer with embedded proteins
fluid mosaic model
36
are complex of polar phosphate head and non-polar hydrocarbon (lipid) tails which is amphipathic in nature
phospholipids
37
has dual polarity
amphiphatic
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proteins that are embedded in the phospholipid layer can be
integral membrane protein
peripheral membrane protein
39
proteins that are embedded through the bilayer
IMP
40
proteins that are embedded only at one side of the bilayer
PMP
41
___ are IMP with associated sugar moieties or chain that serve as cell surface receptors for cell
recognition, membrane transport, or cell communication
glycoproteins
42
___ are lipid with sugar moieties that function more for cell recognition
glycolipids
43
organelles with phospholipid bilayer (some)
vacuoles
nucelus
mitochondria
chloroplasts
44
delineates the cell from its
environment, protects the cell, and regulates the passage of materials into and out of the cell.
plasma membrane
45
Ions pass through the plasma membrane via ____ by ___ and ____
which requires ___
carrier molecules
active transport
facilitated diffusion
ATP
46
made up of various protein
scaffolds inside the cytoplasm which provides structural
support to the cell and aid in cellular movement
cytoskeleton
47
(3) classifications of cytoskeleton
microtubules
intermediate filaments
microfilaments
48
thickest of the cytoskeleton
structures with an average diameter of 25 nanometer
microtubules
49
are rigid hollow cylinders which are polymers of ___ and ____
alpha
beta tubulin protein
50
The two forms of tubulin form ___ or ___ which come together to form the hollow cylinders which is the characteristic form of the microtubules
pairs
dimers
51
They maintain cell shape and hold organelles in place and allow them to move around inside the cell. They
prominently form the ____ during cell division
which moves the chromosomes
microtubules
mitotic spindle
52
microtubules are also the protein component of the cell appendages such as
cilia
flagella
53
numerous hair-like cell surface projections
cilia
54
longer whip-like structure for locomotion
flagella
55
have an average diameter of 10
nanometer and have different composition depending
on the cell type
intermediate filament
56
example of intermediate filaments
keratin
vimentin
desmin
neurofilment
lamin
57
provide support and
mechanical strength to the associated cellular parts and
components
intermediate filament
58
are the thinnest of the cytoskeleton
with an average diameter of 7 nanometer
microfilaments
59
microfilament is made of
two thin actin chains that are twisted around one
another to form a ___
helical configuration
60
___ and __ are responsible for muscular contraction
actin
myosin
61
Microfilaments also form ____
cytoplasmic extension
62
cytoplasmic extension;
numerous microscopic fingerlike projections of the small intestine which increases its
surface area for nutrient absorption
microvilli
63
cytoplasmic extensions
temporary arm-like extension of the plasma membrane
for movement of certain cells or organisms
pseudopods
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(2) cytoplasmic extension
microvilli
pseudopods
65
gel-like aqueous region
between the cell membrane and nuclear membrane
cytoplasm
66
polar solutes that are dissolvved in the cytoplasm
sugars
amino acids
peptides
ions
insoluble cellular inclusions
67
responsible for production of
adenosine triphosphate (ATP), the energy currency of
the cell
mitochondria
68
shape of mitochondria
ovoid
elongated
69
The ___ of mitochondria is convoluted to increase its
surface area for ATP production by electron transport chain and oxidative phosphorylation (ETC-OP).
inner membrane
70
mitochondria have their own small genome which is ___ inherited
maternally
71
organelle that consists of an interconnected network of flattened
membranous sacs, called ____
endoplasmic reticulum
cisternae
72
made up of tubular sacs without studded ribosomes
sER
73
ER that is involved in lipid and carbohydrate biosynthesis
sER
74
also involved in the storage and release of calcium ions in cells and in the detoxification of drugs
and toxicants such as in the liver cells (hepatocytes)
sER
75
is studded with ribosomes and have a flattened appearance
rER
76
involved in the manufacture of various proteins in the cell on the ribosomes that studs its
surface. (ER)
rER
77
rER also modifies proteins by ____ or attachment of sugar moieties and in the ____ of proteins into its proper shape or conformation
glycosylation
proper folding
78
are ribonucleoproteins (RNA +
protein) particles that serve as the site for protein synthesis in the cell in the process called ____
ribosomes
translation
79
ribosomes may appear in clusters called ____
polyribosomes
80
Ribosomes may appear in clusters, or as single free-floating miniscule body in the cytoplasm or attached at the cytoplasmic side of
the plasma membrane, rER, or the nucleus. (t/f)
true
81
ribosomes are made up of ___
two subunits
82
ribosomal large subunit
60S eukaryotes
50S prokaryotes
83
ribosomal small subunit
40S eukaryotes
30S prokaryotes
84
modifies, packages, and "tags" proteinsthat were received from the rER for transportation to
their destined location in the cells.
golgi apparatus
85
GA is made up of highly-folded flattened sacs called
cisternae
86
Present mostly in animal cells and largely absent in plant cells and acts as the cell’s “garbage
disposal organelle.”
lysosomes
87
lysosomes contain various ____ that break proteins, polysaccharides, lipids, nucleic acids, and even
worn-out cellular organelles
acidic hydrolytic enzymes
88
These enzymes are active at ___ the cytoplasm (lysosomes)
pH below
89
enzymes in the lysosomes are are ____ in the lysosomes to protect the other cell parts from degradation by these digesting enzymes
compartmentalized
90
are small, spherical organelles
enclosed by single membrane layer instead of a double layer for most organelles.
peroxisomes
91
peroxisomes carry out ___ reactions
redox
92
redox reactions in peroxisomes
oxidative breakdown of fatty acids and amino acids
93
are also crucial in degrading toxic substances inside the cell such as hydrogen peroxide, H2O2, which
would be damaging to cells as it triggers free radical
damage
peroxisomes
94
Hydrogen peroxide is broken down by the enzyme called ___ which facilitates its conversion to oxygen
gas and water.
catalase
95
specialized peroxisomes in plants which converts stored
fatty acids into sugars particularly in germinating seeds
glyoxysomes
96
membrane-bound
sacs for storage and transport of materials within the
cell. (2)
vacuoles
vesicles
97
larger than vesicles and they do
not fuse with the membranes of other cell organelles
vacuoles
98
Plants cells typically have ___ that can occupy as much as 80% of the cell's volume. They serve to maintain water balance in plants and also for the storage and degradation of polar waste products.
large central vacuole
99
are smaller in size and can fuse with other vesicles or cell organelles. They can store materials inside or transport them outside the cell
vesicles
100
pair of cylindrical
proteinaceous organelles just outside the nucleus of
animal cells
centrioles
101
Each centriole is made up of ___ of microtubules that are arranged in a ___ around a central hollow region (___)
nine triplets
cartwheen fashion
9+0 pattern
102
The centrioles form the ___ during cell division that move the chromosome across the cell.
spindle fibers
103
unique plant cell
organelles that carry out photosynthesis through the
green pigments that it contains, the ____
chloroplasts
chlorophhyll
104
chloroplasts also has its own
DNA and ribosomes and can therefore independently
carry out the replication and expression of its genetic
materials (t/f)
chloroplasts
105
houses the DNA that directs the synthesis of ribosomes and proteins in the cell
nucleus
106
is a membranebound distinct organelle which is darkly stained for
microscopic visualization
nucleus
107
__ is the DNA of the nucleus that is associated with nuclear proteins called ___
chromatin
histones
108
the ___ has condensed chromatin
and serves as the site for ribosome synthesis in the process called ____
nucleolus
transcription
109
the boundary of the nucleus which has a similar stucture to the plasma membrane except for the presence of the ___
nuclear envelope
nuclear pore complex
110
the nuclear pore complex (NPC) which allows the passage of relatively large molecules such as
__ and __ across the membrane
RNA
proteins
111
The ___ is continuous with the endoplasmic reticulum where proteins are packaged
and transported.
nuclear membrane
112
how can you best describe cytoplasm
It is polar, viscous environment
It is delineated by the phospholipid
bilayer of the nucleus and the cell
membrane.
113
characteristics of the
bacterial appendages
✓ They aid in locomotion, conjugation,
and cell surface attachment
✓ They are made up of amino acids
114
How does the fluid mosaic model represents the
structure of the plasma membrane?
✓ The primary component is the
phospholipid bilayer with the
hydrophobic hydrocarbon tail at the
core.
✓ The proteins are embedded which can be located at one side of the lipid bilayer or passing through it.
115
Insulin is a protein produced by the pancreas and released into the bloodstream for lowering
blood glucose level. Which organelles are directly involved in the synthesis and eventual
release of insulin?
✓ Golgi apparatus and vesicles
✓ Ribosomes and rER
116
What are Gram-positive bacteria?
✓ They retain crystal violet dye and thus are stained purple.
✓ They have a cell wall made-up of a thick layer of peptidoglycan.
117
If asked about the mitochondria, how will you best describe such organelles?
✓ They metabolize sugars, amino acids, and fatty acids through a series of reactions that yield energy in the form of ATP.
✓ They have two membranes and the inner membrane has distinct infoldings
118
organelles (2) unique in animal cells
lysosomes
centrioles
119
cell parts/organelles (2) present in both prokaryotic and eukaryotic cells
ribosomes
plasma membrane
120
Which organelles are involved in protein synthesis, modification, and/or transport?
✓ Ribosomes and rER
✓ Golgi apparatus and vesicles
121
Among the given organelles, which ones are present or prominent in plant cells but not in
animal cells?
✓ Vacuoles (central)
✓ Chloroplasts
122
Among the given statements, which ones do not describe the centrioles?
✓ They are active at all times in the cell
✓ They are prominent in all eukaryotic cells
123
Which of the following are true for
cytoskeleton?
✓ They are filamentous in shape and function for support and movement
✓ They are made-up of amino acids
polymers
124
cell organelles (2) that are not enclosed by a phospholipid bilayer
ribosomes
peroxisomes
125
What distinguishes prokaryotes from eukaryotes?
✓ The absence of membrane-bound organelles
✓ The absence of membrane-bound nucleus
126
Which cell organelles have “house cleaning” functions in the cell?
✓ Vacuoles and peroxisomes
✓ Lysosomes and sER
127
Which of the following are not features of the nucleus?
✓ Its nuclear envelope is fundamentally different from the plasma membrane.
✓ It is directly involved in protein
synthesis
128
Which of the following is wrong about the chloroplasts?
✓ It can release energy in the form of ATP just like mitochondria
✓ The stroma contains the green
photosynthetic pigments
129
Which of the following are descriptive of the bacterial DNA?
✓ It is made up of circular doublestranded DNA
✓ There is an extrachromosomal DNA in bacteria which replicates independently
130
Among the given statements, which are characteristics of cell wall?
✓ The plant cell wall is made up of glucose polymers that are cemented by pectin or lignified.
✓ Cell wall is present in bacteria, plants, and fungi
131
Which of the following are true for bacterial capsules?
✓ They are made up of hydrated
carbohydrate complex
✓ They help the bacteria in evading our immune system
