Cells and Organelles Flashcards

FOM 1, Exam 1, Lectures 5, 6, 19

1
Q

What are primary functions of the plasma membrane?

A

selective permeability
exocytosis/endocytosis
cell-to-cell communication

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2
Q

What are the three types of endocytosis?

A

phagocytosis
pinocytosis
receptor-mediated endocytosis

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3
Q

What is phagocytosis?

A

engulf a large amount of material

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4
Q

What is pinocytosis?

A

engulf a small amount of extracellular fluid/ content to help with cellular processes or rebuilding cell membrane

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5
Q

What is receptor-meditated endocytosis?

A

requires binding to a receptor

needs coded proteins

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6
Q

What is the function of clathrin?

A

clathrin is a protein that is under the cell membrane and helps the ligand-bound receptors engulf the ligand from the surface

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7
Q

What is the function of clathrin?

A

clathrin is a protein that is under the cell membrane and helps the ligand-bound receptors engulf the ligand from the surface

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8
Q

What is the distribution of cholesterol in the cell membrane bilayer?

A

evenly distributed in both leaflets of bilayer

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9
Q

What is the distribution of phospholipids in the cell membrane bilayer?

A

asymmetric

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10
Q

What is the distribution of glycolipids in the cell membrane bilayer?

A

exclusively on outer leaflet of bilayer

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11
Q

What are the two faces on an electron micrograph image of a cell membrane?

A

E - face

P - face

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12
Q

What is the E-face on an electron micrograph image of a cell membrane?

A

inner surface of outer leaflet

closer to extracellular space

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13
Q

What is the P-face on an electron micrograph image of a cell membrane?

A

outer surface of inner leaflet

closer to protoplasm

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14
Q

What is the protoplasm?

A

all living parts of the cell on the inside (organelles)

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15
Q

What two types of proteins are found in the cell membrane?

A

integral proteins

peripheral proteins

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16
Q

What are integral proteins?

A

span across the whole membrane (ex. receptors, ion channels)

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17
Q

What is the glycocalyx?

A

a coating on the cell membrane that helps cells adhere to and recognize one another

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18
Q

What is the fluid mosaic model?

A

proteins are clustered in the lipid bilayer but they can move around

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19
Q

What does the membrane asymmetry of the fluid mosaic model refer to?

A

proteins usually stay on their own sides of the membrane

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20
Q

What does the membrane mobility of the fluid mosaic model refer to?

A

proteins can either move rapidly around the membrane or be held stable by intracellular structural elements

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21
Q

What are the most common type of membrane receptors?

A

integral membrane glycoproteins

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22
Q

What are the three domains of glycoproteins?

A

extracellular, transmembrane, and intracellular

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23
Q

What are the three main functions of membrane receptors?

A
  1. control membrane permeability
  2. bind extracellular matrix molecules to cytoskeleton via integrins
  3. relay messages to respond to extracellular events
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24
Q

What are venoms?

A

inactivate acetylcholine receptors of skeletal muscle sarcolemma at neuromuscular junctions

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25
Q

What is the function of channel-linked receptors?

A

open when a ligand bind to allow molecules/ions to move across membrane

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26
Q

What is the function of enzymatic (catalytic) receptors?

A

ligand (usually protein kinases) that bind the receptor induces catalytic activity in associated peripheral proteins

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27
Q

What is the function of G-protein coupled receptors?

A

ion channels/enzyme bound to the cytoplasmic surface of the cell membrane;

bind ligands that change the shape of its G-protein subunit, activating intracellular second messengers

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28
Q

What is the most common G-protein coupled receptor pathway?

A

cyclic adenosine monophosphate (cAMP), Ca2+, and inositol phospholipid-signaling pathway

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29
Q

What is familial hypercholesterolemia?

A

inability to take in cholesterol normally ingested by receptor-mediated endocytosis of LDLs

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30
Q

What are venoms?

A

inactivate acetylcholine receptors of skeletal muscle sarcolemma at neuromuscular junction

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31
Q

What is the cause of autoimmune diseases?

A

self-antibodies that bind to and activate plasma membrane receptors

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32
Q

What are two diseases that result from a damaged G-protein?

A
Cholera toxin (diarrhea)
Pertussis toxin (whooping cough)
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33
Q

What organelles are at the root of all protein synthesis?

A

nucleus and ribosomes

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34
Q

What is the process to make vesicle-packaged proteins?

A

Nucleus → Ribosomes associated with rough ER → Golgi complex → vesicle packaging of proteins

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35
Q

What is the process to make cytoplasmic proteins?

A

Nucleus → Free ribosomes → Cytoplasmic proteins

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36
Q

What are cristae in the mitochondria?

A

folds in the inner membrane

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37
Q

What is the mitochondrial intercristae/matrix space enclosed in?

A

inner membrane

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38
Q

What ion granules are found in the mitochondrial matrix?

A

calcium

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39
Q

What are the three functions of the mitochondria?

A
  1. citric acid and ATP synthesis
  2. buffering of intracellular calcium (organelle of last resort)
  3. induce apoptosis
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40
Q

How does hypoxia affect the mitochondria?

A
  1. destroy proteins for oxidative phosphorylation
  2. swells
  3. ETC will be damaged
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41
Q

What tissues do mitochondrial defects affect the most?

A

tissues that use large amounts of ATP (ex. muscle cells and neurons)

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42
Q

What is the cause of myoclonic epilepsy with ragged-red fibers?

A

aggregation of abnormal mitochondria that look like red fibers due to mutation in mitochondrial DNA

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43
Q

What is myoclonus?

A

muscle spasms

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44
Q

What are the symptoms of myoclonic epilepsy?

A

muscle weakness
ataxia
seizures
cardiac and respiratory failure

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45
Q

What is ataxia?

A

impaired coordination

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46
Q

What are the components of ribosomes?

A

two subunits and rRNA

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47
Q

What is the function of ribosomes?

A

synthesize proteins

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48
Q

What is the template that ribosomes use to synthesize proteins?

A

mRNA

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49
Q

What is rough endoplasmic reticulum comprised of?

A

tubular system of membranes that is continuous with the nuclear membrane

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50
Q

What is the function of endoplasmic reticulum?

A

synthesize proteins

  • secretion
  • form other organelles
  • package to transport to Golgi
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51
Q

What are the six functions of the smooth endoplasmic reticulum?

A
  • detox
  • steroid hormone synthesis
  • cholesterol metabolism
  • buffering of intracellular calcium (organelle of first resort)
  • break down glycogen in liver
  • lipid synthesis
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52
Q

What is the Golgi apparatus comprised of?

A

stacked cisternae with vesicles budding off

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53
Q

What are the three functions of the Golgi apparatus?

A
  • receives proteins and lipids from rough ER

- package proteins and send out

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54
Q

What enzymes do lysosomes contain?

A

hydrolytic (acid hydrolases)

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55
Q

In what cells are lysosomes abundantly present?

A

phagocytic cells (ex. macrophages)

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56
Q

What is the difference between primary and secondary lysosomes?

A

primary - brand-new assembled by Golgi complex

secondary - activated when fused with phagosomes

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57
Q

What are phagosomes?

A

vesicles containing phagocytic materials

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58
Q

What are residual bodies?

A

works on breaking down debris that lysosomes have a hard time digesting

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59
Q

What do residual bodies contain?

A

lipofuscin - a yellowish fat soluble pigment

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60
Q

What do proteasomes break down?

A

cellular proteins that have been tagged by ubiquitin

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61
Q

What is the function of ubiquitin ligase?

A

connect proteins with ubiquitin

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62
Q

What are the four functions of peroxisomes (microbodies)?

A
  • production and breakdown of hydrogen peroxide (bactericidal)
  • lipid metabolism
  • bile salt synthesis
  • detox
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63
Q

What oxidative enzymes do peroxisomes contain?

A

amino acid oxidases

hydroxyacid oxidase

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64
Q

What do peroxisomes use to break down hydrogen peroxide?

A

catalase

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65
Q

What are secretory granules?

A

small granules that release things outside of the cell (ex. neurotransmitters, hormones, enzymes, etc.)

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66
Q

What are three types of inclusions in the cell?

A
  • fat droplets
  • glycogen granules
  • pigment deposits
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67
Q

What are the four different types of pigment deposits?

A
  • melanin
  • hemosiderin
  • lipofuscin
  • bilirubin
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68
Q

What are the three components of the cytoskeleton?

A

microtubules
actin filaments
intermediate filaments

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69
Q

How are microtubules formed?

A

alpha and beta subunits that grow off the “leading edge” into a cylinder

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70
Q

What are the four specialized types of microtubules?

A

centrioles
cilia + flagella
mitotic spindles
basal bodies

71
Q

What are centrioles?

A

center for microtubule formation in cells

72
Q

What is the arrangement of microtubules for centrioles?

A

9 sets of 3 with no central microtubules (9+0 arrangement)

73
Q

What is the function of cilia and flagella?

A

propulsion

74
Q

What is the arrangement of microtubules for cilia and flagella?

A

9 sets of 2 with 2 central microtubules (9+2 arrangement)

75
Q

What is a basal body?

A

microtubule anchor at base of cilia and flagella

76
Q

What are mitotic spindles?

A

centrioles that organize meiosis

77
Q

List the three components in the cytoskeleton from smallest to largest diameter

A

microfilaments
intermediate filaments
microtubules

78
Q

What is the function of intermediate filaments?

A

structural support

79
Q

What is the specific intermediate filament for epithelial cells?

A

cytokeratins

80
Q

What is the specific intermediate filament for muscle cells?

A

desmin

81
Q

What is the specific intermediate filament for astrocytes?

A

GFAP (glial fibrillary acidic protein)

82
Q

What is the specific intermediate filament for nuclei?

A

lamins

83
Q

What is the specific intermediate filament for neurons?

A

peripherin

84
Q

What is the specific intermediate filament for mesenchymal cells?

A

vimentin

85
Q

What is the function of microfilaments (actin filaments)?

A

cell movement

86
Q

What is the cause of jaundice?

A

accumulation in extracellular fluid of bilirubin and other pigmented compounds

87
Q

What organ usually metabolizes bilirubin?

A

smooth endoplasmic reticulum enzymes in liver cells

88
Q

What are lysosomal storage disorders?

A

deficiency in specific lysosomal acid hydrolases

compounds accumulate and interfere with cell function

89
Q

What are the two peroxisomal diseases?

A

Zellweger syndrome

Neonatal adrenoleukodystrophy

90
Q

What is Zellweger syndrome?

A

normal peroxisomes are absent

91
Q

How are microtubule dynamics used to treat cancer?

A

inhibitory compounds prevent cancerous cells from forming the mitotic spindle

92
Q

What is neonatal adrenoleukodystrophy?

A

inability of peroxisomes to metabolize fatty acids

93
Q

How are tumors diagnosed?

A

looking at intermediate filaments

94
Q

How big is the nucleus?

A

5-10 micrometers

95
Q

What is the nuclear envelope comprised of?

A
two membranes 
perinuclear cisternae (space) in between
96
Q

What allows for transport of macromolecules in the nuclear envelope?

A

nuclear pores

97
Q

What organelle is the nuclear envelope continuous with?

A

rough ER

98
Q

What are the two types of chromatin?

A

euchromatin

heterochromatin

99
Q

What are the locations of euchromatin vs. heterochromatin?

A

euchromatin - medially located

heterochromatin - eccentric in location

100
Q

What are the densities of euchromatin vs. heterochromatin?

A

euchromatin - light

heterochromatin - dense

101
Q

What are the transcriptional activities of euchromatin vs. heterochromatin?

A

euchromatin - transcriptionally active

heterochromatin - metabolically inactive

102
Q

What is a nucleosome?

A

smallest structural unit of chromatin

103
Q

What is the nuclear lamina?

A

internal to inner nuclear membrane to which chromatin is attached

104
Q

What is the function of the nucleolus?

A

assembles ribosomes

105
Q

What does the nucleolus use to assemble ribosomes?

A

ribosomal proteins (from cytoplasm) and mature rRNA

106
Q

What is karyokinesis?

A

division of the nucleus

107
Q

What is cytokinesis?

A

division of the cell

108
Q

What happens during the S phase?

A

replicates DNA and centrioles

109
Q

What happens during prophase?

A

nucleolus disappears
dispersed chromosomes
nuclear envelope fragments

110
Q

What happens during metaphase?

A

chromosomes line up

111
Q

What happens during anaphase?

A

sister chromatids separate

112
Q

What happens during telophase?

A

nuclear envelope reforms

cytokinesis

113
Q

What kinase controls mitosis?

A

cyclin-dependent kinases (associated proteins are cyclins)

114
Q

What is p53?

A

tumor suppressant protein

115
Q

What are the two divisions of meiosis called?

A

reductional

equatorial

116
Q

What is non-disjunction?

A

failure to separate - can lead to trisomies

117
Q

What are the three types of cell death?

A

necrosis (after trauma)
apoptosis (natural cell turnover)
autophagy (controlled signaling process)

118
Q

What is the process of necrosis?

A
  1. cell membrane lyses
  2. organelles swell
  3. extracellular environment mixes with cytoplasm
  4. debris is consumed by macrophages
119
Q

What is the process of apoptosis?

A
  1. cell condenses
  2. membrane bulges
  3. cytoskeleton breaks down
  4. mitochondria activates death proteins
  5. nucleus breaks down
  6. rest of the cell breaks down
120
Q

What is the process of autophagy?

A

cell uses lysosomes to destroy itself

121
Q

What are the two determinants of membrane permeability?

A

hydrophobicity

size

122
Q

What are the two types of potential gradients?

A

electrical

chemical

123
Q

What is primary active transport?

A

when the ATP energy source is directly coupled to the transport process

124
Q

What is the function of cardiac glycosides?

A

drugs that inhibit Na+ K+ ATP-ase

125
Q

What is the function of a plasma-membrane Ca2+ ATPase (PMCA)?

A

extrude Ca2+ from the cell against an electrochemical gradient

126
Q

What is the Ca : ATP ratio for PMCA?

A

1:1

127
Q

What is the Ca : ATP ratio for SERCA?

A

2:1

128
Q

What is secondary active transport?

A

when the transport of two or more solutes are coupled

indirect use of ATP for energy

129
Q

What are the two types of secondary active transport?

A

cotransport (symport)

countertransport (antiport)

130
Q

What is an example of cotransport (symport)?

A

Na+ and glucose

131
Q

What is an example of countertransport (antiport)?

A

3 Na+ and 1 Ca+

132
Q

What are the two solutions to an osmotic pressure difference?

A

increase osmotic pressure of surrounding fluid

reduce molecules in the cell

133
Q

What is the Na+ K+ ATPase stoichiometry?

A

3 Na+ out
2 K+ in
1 ATP

134
Q

What happens to a RBC in hypertonic fluid?

A

shrivels (crenated)

135
Q

What happens to a RBC in hypotonic fluid?

A

swells

136
Q

What happens to a RBC in very hypotonic fluid?

A

lyses

137
Q

What feature of the cell membrane is used for high rates of water transport?

A

aquaporins

138
Q

What organs have high rates of water transport?

A

kidney
lungs
salivary glands

139
Q

What is a channel vs. a carrier?

A

channel - simple hole, selective, gated

carrier - conformational changes after binding

140
Q

What is the order of “channel” “carrier” and “pump” from most to least specific?

A

pump
carrier
channel

141
Q

What is the function of ATP binding cassettes?

A

convert the energy gained from ATP hydrolysis into movement of substrates either into the cytoplasm (import) or out of the cytoplasm (export)

142
Q

What is the function of multi-drug resistant proteins?

A

ABC transporters

pump out hydrophobic molecules

143
Q

What is the cause of cystic fibrosis?

A

inhibition of Cl- membrane permeability which leads to increased viscosity of body secretions

144
Q

What is the ABC associated with cystic fibrosis?

A

cystic fibrosis transmembrane regulator (CFTR)

145
Q

What are the two properties that impact ion channels?

A

gating

ion selectivity

146
Q

What are the four different types of ion-gated channels?

A

voltage
ligand (extracellular)
ligand (intracellular)
mechanical

147
Q

What is the purpose of patch clamping?

A

to study ionic currents

148
Q

What three features do all forms of carrier-mediated transport share?

A

saturation
stereospecificity
competition

149
Q

What are the steps for a stem cell to become a mature cell?

A

stem cell
transit-amplifying cell/colony forming units
blast cells
mature cells

150
Q

Where are totipotent stem cells found?

A

zygote or early embryo

151
Q

What do totipotent stem cells become?

A

pluripotent embryonic stem cells

152
Q

Where are pluripotent embryonic stem cells found?

A

blastocyst

153
Q

What do pluripotent embryonic stem cells become?

A

multipotent adult stem cells

154
Q

What are multipotent adult stem cells found in?

A

every tissue and organ in adults

155
Q

What are induced pluripotent stem cells?

A

somatic (adult) cells reprogrammed to enter an embryonic stem cell–like state

156
Q

What are blast cells?

A

more restricted developmental choices than stem cells

157
Q

What are the hematopoietic blast cells?

A

myeloblast

erythroblast

158
Q

What are the neural blast cells?

A

neuroblast

159
Q

What are the osteogenic blast cells?

A

osteoblasts

160
Q

What is the relationship between daughter and parent blast cells?

A

Daughter cells are often more mature than the parent

cell.

161
Q

What are mature cells?

A

Final commitment to a specific cell fate

162
Q

What are transit-amplifying cells?

A

can proliferate and self-renew to produce more mature daughter cells

163
Q

What is parenchyma?

A

functional cells of that organ

164
Q

What is stroma?

A

supporting cells and tissues

165
Q

What is the general organization of solid tissues?

A

parenchyma and stroma

166
Q

What is the general organization of tubular tissues?

A

epithelium
basement membrane
lamina propria
tissue-specific lamina

167
Q

What is the basement membrane?

A

an acellular barrier

168
Q

What is the lamina propria?

A

connective tissue support

169
Q

What is adventitia?

A

loose connective tissue that connects the organ to the surrounding tissues

170
Q

What is serosa?

A

thin membrane lining the closed cavities of the body; has two layers with a space between that is filled with serous fluid

171
Q

What three components does the formation of an organ require?

A

cells
programming and growth factors
extracellular matrix

172
Q

What two components of and organ interact to influence its shape?

A

cell and matrix

173
Q

What is chemotaxis?

A

chemical signals that tell cells where to go

174
Q

How does notch influence the fate of tissue?

A

differentiates arterial and venous tissue