Chapter 4 Flashcards
(195 cards)
1
Q
cluster of atoms held together by chemical bonds
A
molecule
2
Q
structure within a cell that performs a specific function
A
organelle
3
Q
simplest entity that has all the properties of life; a membrane-bound unit containing DNA and cytoplasm
A
cell
4
Q
structures composed of more than one tissue type
A
organ
5
Q
related organs performing a common function
A
organ system
6
Q
an individual, independent, living entity
A
organism
7
Q
form boundaries on surfaces (outermost layer of skin, line airway and stomach), control what goes in and out, held by tight junction
A
epithelial tissue
8
Q
cells imbedded in a matrix (ex. blood: RBC surrounded by a liquid matrix called plasma & bone which has a calcified matrix collagen fibers & adipose tissue)
A
connective tissue
9
Q
skeletal, smooth (blood vessels, GI tract), cardiac
A
smooth tissue
10
Q
neurons conduct electrical signals
A
nervous
11
Q
chemical pathway from simple to complex
A
anabolism
12
Q
chemical pathway from complex to simple
A
catabolism
13
Q
Living things….
A
cellular organization, sensitivity (respond to stimuli), growth, reproduce, homeostasis
14
Q
Cell theory
A
1) all organisms are composed of cells 2) the cell is the basic building block of life = chemical reactions within 3) all cells come from preexisting cells
15
Q
Why are cells small?
A
need high/reasonable surface-to-volume ratio and big cell = diffusion distance increases = not efficient
16
Q
two atoms SHARE one, two, three electron pairs –> stable bond
A
covalent bonds
17
Q
water molecule is formed by ___ bonds between one oxygen atom and two hydrogen atoms
A
covalent
18
Q
oppositely charged ions attract each other forming an ___ bond
A
ionic
19
Q
unequal attraction of electrons by the atoms that share them in a covalent bond
A
polar molecule
20
Q
the attraction of the positive (hydrogen) end of the polar molecule to the negative end of another polar molecule is called
A
hydrogen bond
21
Q
hydrogen bonds may be weak but can be present in ____ and influence the shape of molecules (DNA double helix is held together by H bonds)
A
very large numbers
22
Q
water forces the hydrophobic groups together and this is why non polar groups tend to localize ____ of most soluble proteins
A
within the interior
23
Q
lacks a nucleus; DNA coiled into a nucleoid is in direct contact with the cytoplasm (some have more than one nucleoid)
A
prokaryotic cells
24
Q
contain a large, membrane bounded nucleus; has organelles
A
eukaryotic cells
25
All prokaryotic cells have a plasma membrane, nucleoid, and cytoplasm containing ____
ribosomes
26
Prokaryotic: located outside plasma membrane may be a ___
cell wall containing peptidoglycan
27
plasma membrane --> cell wall --> outer membrane --> ___
capsule
28
In bacteria the chlorophyll (no chloroplast) is located in
the infoldings of the plasma membrane
29
some prokaryotes swim using
flagella
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___ which projects from the surface of some bacteria is involved in mating
pili
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prokaryote flagellum is made up of
flagellin
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Eukaryotes contain an internal cytoskeleton which
maintains cell shape and moves materials
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rigid cell wall of cellulose and large central vacuole
plants
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eukaryotes's cytoskeletal protein is made up of
myosin and actin
35
ER closest to nucleus
rough (ribosomes)
36
mature RBC
blood cells originate from blood bone marrow; last bout 120 days then broken down in liver
no nucleus cuz going to lose genetic material anyways
37
DNA is contained in
mostly nucleus + mitochondria and chloroplast
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DNA + protein -->
chromatin
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when nucleus is about to divide the chromatin ___ forming chromosomes
condenses and coils tightly
40
each __ ("colored body") contains one long molecules of DNA comprising many genes
chromosomes
41
the nucleus contains (one or more) nucleolus the site of
ribosome assembly
42
fluid material within the nuclear envelope
nucleoplasm
43
viruses are made up of __, surrounded by ____
nucleic acid, protein sheath (sometimes lipid envelope)
44
viruses are not alive because
lack cell membranes, nucleus, and organelles; cannot reproduce on their own; no metabolism
45
X formation is ___ to division
prior
46
mitotic spindle is attached to each ____ and pulls them apart to the poles
sister chromatid
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all cells synthesize proteins on __
ribosomes
48
Where are ribosomes located in eukaryotes?
free in cytoplasm, attached to rough ER, in energy producing organelles (mitochondrial matrix, chloroplast stroma)
49
ribosomes consist of a type of ___ together with protein, comprising a large and small subunit which associate during protein synthesis
RNA
50
____ makes the peptide bond
ribozyme
51
A series of interrelated membranes and compartments in the eukaryotic cells
Endomembrane system = ER + Golgi
52
extensive system of folded membranes forming sacs and tubes
ER
53
cells which synthesize proteins for export contain large amounts of ____
ER
54
lack ribosomes; site for hydrolysis of glycogen; steroid synthesis
smooth ER
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contains attached ribosomes; makes proteins for export; site for addition of short sugar chains to proteins glycoproteins
rough ER
56
insulin is made and stored in ___
pancreatic beta cells (right below stomach)
57
enclosed spaces
lumen
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series of flattened membranous sacs that modifies, packages, and sorts proteins
Golgi apparatus
59
synthesizes some polysaccharids for the cell wall
Golgi apparatus
60
vesicles from the rough Er fus with the ___ region of the Golgi (near nucleus) and secretory vesicles are pinched off the the ___ region (close to cell surface)
cis, trans
61
powerhouse of cell
mitochondria
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food is converted into ATP =
energy currency of cell
63
mitochondria are small/big
small (bacteria size)
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inner membrane of mitochondria
cristae
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mitochondrial matrix contains
ribosomes and DNA
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almost all eukaryotes contain mitochondria except whose living
without oxygen
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more mitochondria are present if cells are ___ like in heart muscle
very active
68
serves for food manufacture or storage in plants and some protists (ex. chloroplast)
plastids
69
plastids are surrounded by
two unfolded membranes
70
inner membrane of chloroplast forms a stack of flattened disk-like sacs called
thylakoids
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stacks of thylakoids are called
grana
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chlorophyll is contained in
the thylakoid membrane
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___ (fluid) within inner membrane of chlorplast contains suspended grana, ribosomes, and DNA
stroma
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contains hydrolytic digestive enzymes; participate in phagocytosis
lysosomes
75
What is the pH of lysosomes
5
76
peroxisomes are found in
plants and animals
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glyoxysomes are found in ___, it stores ___ which is converted in carbs when plant is about to germinate
plant seeds, lipids
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peroxisomes are important in liver and kidney to
detoxify
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Tay Sach's disease
defect in lysosomes
80
lysosomes carry out autophagy which is
self-breakdown
81
T or F: plants have lysosomes
false
82
vacuoles are present in ___
plant cells; store waste products and provide turgor
83
maintains cell shape, facilitates cell movement, and certain fibers act as tracks for "motor proteins"
cytoskeleton
84
cell wall are present in __, ___, and some __
plants, fungi, protists (and bacteria)
85
surrounds animal cells and is composed of proteins (e.g. collagen, glycoproteins, and proteoglycan)
extracellular matrix
86
division of the nucleus
mitosis
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division of cytoplasm
cytokinesis - microfilaments form a noose around the middle of the cell it adds or subtract to change length of actin
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strands of actin, involved in movement during animal cell division and muscle contraction
microfilaments
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tough, fibrous protein molecules twisted into rope-like structures, which stabilize cell structure
intermediate filaments
90
hollow cylinders made of tubulin
microtubules
91
involved in structure and function of cilia and flagella, centrioles, and movement of cellular organelles
microtubules
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motor proteins such as __ use energy from ATP to change their shape and move things
dynein and kinesin
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cilia are formed of
microtubules
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structure of cilia
9 pairs of microtubules + 2 in the middle
95
animals don't have cell wall but may have
extracellular matrix
96
vacuoles are __ in animal cells
absent or small
97
some animal cell have flagella it's absent in plants except for
sperm in a few species
98
centrioles ___ in plants
are absent
99
all cells are bounded by a __
plasma membrane
100
plasma membrane provides __ which has the ability to transport certain molecules
permeability barrier
101
plasma membrane plays a key role in response of cells to __
external stimuli
102
membranes are involved in energy __
transduction
103
biological membranes are composed of
lipids, proteins, and carbohydrates
104
provide physical integrity of plasma membranes
lipids
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perform specific function (e.g. transport, receptors) for plasma membrane
proteins
106
serve as recognition sites on the cell surface
carbohydrates
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the basic foundation of the plasma membrane
lipid bilayer
108
phospholipids ___ form bilayer sheets in which the ___ tails point inward
spontaneously, hydrophobic
109
fluidity of a bilayer depends on __ and ___
composition and temperature
110
important component of plasma membrane of animal cells orients in bilayer with polar head group close to polar head group of phospholipid
cholesterol
111
unsaturated: C=C puts a kink in a chain so it does not pack well together in membrane -->
harder to freeze
112
on the outer surface of the plasma membrane, __ are attached to proteins or phospholipids
carbohydrates
113
protein that penetrates into the lipid bilayer
integral
114
most integral proteins are __, contain an alpha-helix of non polar amino acids extending across the hydrophobic interior of the membrane
transmembrane
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located outside of the lipid bilayer on the cytoplasmic surface attached by non covalent bonds to the polar head groups of the lipid bilayer or to the integral membrane proteins
peripheral proteins
116
covalently attached to a phospholipid or fatty acid embedded in the bilayer
lipi-anchored proteins
117
__ provides much info we know about membrane structure
RBC
118
beneath the cytoplasmic surface of the RBC, ___ forms a mesh
spectrin
119
role of membrane proteins
transport, receptors, form junctions between cells
120
cells can recognize and bind to each other via ___
surface membrane proteins
121
stick together by same membrane proteins
homotypic binding
122
stick together by different membrane proteins
heterotypic binding
123
cell junction stitched all the way around
tight junction
124
"spot welds" don't go all the way around but more concerned with structural integrity
desmosomes
125
protein pore or channel between two adjacent cells
gap junctions
126
connexin protein makes a channel called
connexon
127
gap junctions are important in __
the heart, facilitates the spread of an action potential
128
meditate the attachment of animal cells to extracellular matrix
inegrin
129
passive, non mediated movement down concentration gradient most simple
diffusion
130
when molecules become uniformly distributed a state of __ exists
equilibrium
131
diffusion of water molecules across a selectively permeable membrane
osmosis
132
Ions such as Na+ and other charges do not readily cross membranes but can pass through water filled pores created by ____
intrinsic membrane proteins (channels)
133
certain molecules (eg glucose) bind to carrier proteins in the membrane and are transported across
facilitated diffusion
134
facilitated diffusion may become ___ if all the protein carriers are in use
saturated
135
transport across a membrane by a carrier-mediated process against concentration gradient
active transport
136
requires direct participation of ATP
primary active transport
137
does not use ATP directly but rather the energy in an ion gradient established by primary active transport
secondary active transport
138
transports macromolecules, large particles, and small cells into eukaryotic cells
endocytosis
139
during endocytosis, the plasma membrane envelops materials and forms ___ inside cells
vesicle
140
large particles or cells are engulfed
phagocytosis
141
small dissolved solutes or fluids enter
pintocytosis
142
a specific membrane receptor binds to a particular macromolecule at sties called coated pits (e.g. uptake of cholesterol in association with LDL)
receptro-mediated
143
material in vesicles are secreted from the cell when vesicles fuse with the plasma membrane
exocytosis
144
work associate energy
kinetic
145
stored energy
potential
146
energy from the sun flows in the biological world and stored as ___ in the chemical bonds of sugar molecules formed by photosynthesis
potential energy
147
first law of thermodynamics
energy cannot be created or destroyed
148
second law of thermodynamics
during any energy conversion, some energy is released as heat which adds to entropy (increasing disorder) of the system
149
the sum of all chemical reactions within a cell or organism
metabolism
150
product of one reaction becomes the reactant in the next reaction
metabolic pathway
151
chemical reaction establish
equilibrium
152
what is the ratio of the concentration of products and reactants at equilibrium
equilibrium constant Keq
153
high Keq -->
reaction goes far towards completion
154
the breaking of chemical bonds in the course of chemical reactions produces changes in ___
Gibbs free energy
155
Give an example of an anabolic reaction
glucose + fructose + (energy) --> sucrose
156
Give an example of a catabolic reaction
sucrose is hydrolyzed --> energy is released
157
in a biological system, the released energy may be __ in new chemical bonds or used as __
recaptured, kinetic energy
158
the energy released by the breakdown of glucose is used to drive the synthesis of ___
triglycerides
159
Total energy
enthalpy, H
160
G =
H-TS
161
If delta G < 0
free energy is released, exergonic
162
If delta G > 0
free energy is required, endergonic
163
the further toward completion the point of equilibrium lies, the ___ free energy is released
more
164
The proteins of tight junctions form a ___ barring the movement of dissolved materials through the space between epithelial cells
quilted seal
165
__ link adjacent cells tightly but permit materials to move around them in the intercellular space
Desmosomes
166
Gap junctions let adjacent cells ___
communicate
167
__ and __ are abundant in epithelial cells
tight junctions and desmosomes
168
__ are found in some muscle tissue and nerve tissue win which __ between cells is important
gap junctions, rapid communication
169
True or False: All three junctions are not necessarily seen at the same time in actual cells
true
170
A __ solution has a higher solute concentration than the other solution
hypertonic
171
__ solutions have equal solute concentrations
isotonic
172
A __ solution has a lower solute concentration that the other solution
hypotonic
173
How fast a substance diffuses depends on
diameter or molecules or ions, temperature of solution, concentration gradient
174
__ keeps plants upright and is the driving force for the enlargement of plant cells
turgor pressure
175
sometimes a stimulus is the binding of a chemical signal __ to open gated channel
ligand
176
Protein __ coats the cytoplasmic side of the plasma membrane at the coated pit
clathrin
177
the endocytosed contents are surrounded by
a clathrin-coated vesicle
178
__ is the method by which cholesterol is taken up by most mammalian cells
receptor-mediated endocytosis
179
When a cell need cholesterol, it produces specific __ which are inserted into the plasma membrane in clathrin coated pits
LDL receptors
180
A newly formed polypeptide may contain a __ which is a short stretch of amino acids that indicates where in the cell the polypeptide belongs
signal sequence
181
A signal sequence binds to a specific __ at the surface of the organelle
receptor protein
182
in the absence of a signal sequence, the protein will __ in the same cellular compartment where it was synthesized
remain
183
protein synthesis always begins on free ribosomes and have default location for a protein is the __
cytosol
184
Once the protein has bound to a specific receptor protein, the receptor forms a __ in the membrane and the protein enters the organelle
channel
185
a specific hydrophobic sequence of about __ at the beginning of a polypeptide chain directs it into the ER
25 amino acids
186
Nucleic acids inside protocells could replicate using the ___ from ___
nucleotides from outside
187
found in cytoplasm (on ribosome), binding of mRNA and tRNA and protein synthesis
rRNA
188
found in cytoplasm, carrier of gene sequence
mRNA
189
found in cytoplasm, adapter between mRNA and protein sequences
tRNA
190
in plants, SER
metabolizes carbohydrates
191
membranes of the nucleus, ER, and Golgi form a
network connected by vesicles
192
Blood Cholesterol Levels
200 mg/dL, 200-239, 240+
193
LDL cholesterol levels
130 mg/dL, 130-159, 160+
194
Blood cholesterol made in
liver
195
cholesterol is coated with a layer of protein to make __ which can move in blood
lipoprotein
