Exam 3 - Cell Physiology

Front 1

Plasma membrane is different from cell membrane how?

Back 1

plasma membrane is the other membrane of a cell while a cell membrane can be any membrane within a cell

Front 2

3 components of plasma membrane?

Back 2

The ampipathic lipid bilayer
sugars and proteins
cytosolic (submembrane) protein meshwork

Front 3

what does ampipathic mean ? as in an ampipathic lipid bilayer

Back 3

means it has both a HYDROPHOBIC and HYDROPHILIC component

Front 4

cytosolic protein meshwork is only found where?

Back 4

on the cytosolic side of the plasma membrane

Front 5

How many types of phospholipids are there?

Back 5

about 5
(phosphotidyl ethanolamine, phosphotidyl serine, phosphotidyl choline, spingomyelin, springosine)

Front 6

Glycolipids and cholesterol are what kinds of molecules?
where are they found?

Back 6

lipids, found within plasma membrane
(creates fluidity within membrane)

Front 7

Does being a polar molecule help it diffuse across a plasma membrane without aid?

Back 7

Nope, it makes it much harder. For a polar molecule to cross a membrane it has to be pretty darn small

Front 8

Can charged molecules diffuse across a plasma membrane without aid?

Back 8

NEVER, no matter how tiny, charged molecules dont diffuse

Front 9

definition of Integral membrane proteins?
definition of Peripheral membrane proteins?

Back 9

Integral: part of the plasma membrane (embedded)
Peripheral: interact directly with the integral membrane proteins (not directly attached)

Front 10

What is a transmembrane protein?

Back 10

A protein within the plasma membrane which has domains on both sides of the membrane

Front 11

What is a channel within a protein membrane composed of?

Back 11

beta pleated sheets shaped into a tunnel so that ions can go through

Front 12

Diffusion is defined by moving down a concentration gradient. This is why _______ diffusion and diffusion are both considered passive diffusion even though one uses proteins and one method doesnt

Back 12

facilitated

Front 13

The myelin Sheth is composed of ____% protein and _____% lipids.

Back 13

20% protein and 80% lipids

Front 14

The more activities the membrane carries out the ______ the protein to lipid ratio.

Back 14

higher (more proteins, more activities)

Front 15

The outer mitochondrial is composed of ____% protein and _____% lipids.

Back 15

50% protein and 50% lipids

Front 16

The inner mitochondrial is composed of ____% protein and _____% lipids.

Back 16

80% protein and 20% lipids

Front 17

Sugars are found where on the plasma membrane?

Back 17

on the non-cytosolic side (because they would dissolve in the cytosol)

Front 18

another way to say cytosolic/non-cytosolic layer is a cytosolic/non-cytosolic _______

Back 18

leaflet

Front 19

sugar residues on the plasma membrane are found where?

Back 19

on the non-cytosolic leaflet

Front 20

Where is the cytosolic submembrane protein meshwork found?

Back 20

under the cytosolic layer of the plasma membrane

Front 21

Name 5 structures that live in the submembrane meshwork.

Back 21

ribosome docking proteins, chaperonin docking proteins, anchor proteins for cadherins and integrins, membrane identification proteins, 2nd messengers for signaling pathways

Front 22

What are the Principle Functions of Cell Membranes?

Back 22

Compartmentilization of Cell Functions, Defense and Integrity of Cellular or Compartmental Contents, Selective Permeability in Two Directions, Regulation of Internal Cellular or Compartmental Activities, Attachment and Movement of the cell or Compartment, Response to Signals from Outside of the Cell or Compartment

Front 23

The nucleus and the ER are connected how?

Back 23

Directly attached

Front 24

most lipids are synthesized where?

Back 24

in the smooth ER

Front 25

Where does detoxification of dangerous materials occur?

Back 25

in the ER

Front 26

Where does calcium sequestration occur?

Back 26

in the ER

Front 27

The condition of the ___(in/out)side_____of the ER is analogous to the of the ___________side of a plasma membrane

Back 27

inside, non-cytosolic

Front 28

is a nuclear pore large or small?

Back 28

huge!

Front 29

What is glycosylation and where does it occur?

Back 29

its a post-translational protein modification where carbohydrate residues are added to proteins, lipids and more. It occurs in the Golgi

Front 30

The different layers of the Golgi are called?

Back 30

Cisterna

Front 31

Endomembrane system includes.....

Back 31

the nucleus, the ER, Golgi, lysosome, and plasma membrane
(organalles that contain membranes which can exchange things to and fro)

Front 32

Phagocytosis is a form of ______

Back 32

endocytosis

Front 33

Phagosomes are taken in via _________

Back 33

phagocytosis

Front 34

Which organelles contain double membranes?

Back 34

Mitochondria, chloroplasts and nucleus

Front 35

What are the organelles than can increase in amount when cell division is NOT occuring?

Back 35

mitochondria, chloroplasts and peroxisomes

Front 36

Peroxisomes do what?

Back 36

Kill free radicals

Front 37

Peroxisomes work overtime in which kinds of cells?

Back 37

cancer cells

Front 38

Hydrogen peroxide is used within a _______ to stabilize free radicals

Back 38

peroxisome

Front 39

______ synthesis occurs in the peroxisome

Back 39

lipid

Front 40

vacuoles are found in ________

Back 40

plants

Front 41

central vacuoles hold _____

Back 41

water
(erect plant vs wilted plant)

Front 42

A food or water vacuole serves as a ______ unit

Back 42

storage

Front 43

The Microtubule organizing center near the nucleus is called the _______

Back 43

centrosome

Front 44

The subunits of microtubules are called _____

Back 44

tubulin

Front 45

Tubulin is organized into microtubulin by ______ _______ _______

Back 45

microtubulin organizing centers

Front 46

the spindle apparatus is formed within the _______

Back 46

centrosome

Front 47

What are the 3 components of the cytoskeleton?
from smallest to biggest

Back 47

microfilaments (thin), intermediate filaments, microtubules

Front 48

What are microfilaments composed of?

Back 48

actin

Front 49

Which 2 of the 3 components of the cytoskelton have motor proteins?

Back 49

microtubules and microfilaments

Front 50

Microfilaments are found on the cell ______ (outer edge of a cell)

Back 50

cortex

Front 51

actin is also called _________

Back 51

Gactin (globular actin)

Front 52

microtubules are composed of

Back 52

tubulin

Front 53

The subunits of intermediate filaments are _____-______

Back 53

cell specific (7-8 different proteins that vary based on cell type)

Front 54

intermediate filaments are found in both the ______plasm and the ____ cytoplasm

Back 54

nucleoplasm, cytoplasm

Front 55

intermediate filaments within the nucleus = ________ ________

Back 55

nuclear scaffold

Front 56

molecular motors do what?

Back 56

help with the transport of materials, and helps cells move

Front 57

Other protein that is associated with the cytoskeleton that is not tubulin or Gactin?

Back 57

molecular motors (motor proteins)

Front 58

The linkage of Gactin requires_______

Back 58

ATP

Front 59

If a Gactin is linked to ADP, can it polymerize?

Back 59

No, needs energy (ATP)

Front 60

Gactin is always bound to either _____ or _____

Back 60

ATP or ADP

Front 61

what is a contractile bundle?

Back 61

a loose bundle of microfilaments (space inbetween) (ex:stress fiber)

Front 62

Another word for bundle....

Back 62

aggregate

Front 63

What is a gel-like network?

Back 63

loosely bound microfilaments crossing over each other, found in cell cortex

Front 64

What is a tight parallel bundle?

Back 64

A tight bundling of microfilaments, found in filopodium (microvilli)

Front 65

What are the 3 types of bundling in microfilaments

Back 65

contractile, gel-like, and tight parallel bundling

Front 66

Is Gactin polar or non-polar?

Back 66

polar

Front 67

What is a MFAP?
give an example

Back 67

Microfilament Associated Proteins (MFAPs)
motor protein

Front 68

Assembly/disassembly of a microfilament take place at the ____ end

Back 68

plus

Front 69

The plus end of microfilaments are very ______

Back 69

dynamic

Front 70

The main isoforms of microtubules

Back 70

alpha, beta, gamma

Front 71

How many protofilaments make up a microtubule?

Back 71

13 (sometimes 10)

Front 72

Tubulin must be bound to _____ to be used for assembly (analogous to Gactin with ATP)

Back 72

GTP

Front 73

The inside of a microtubule is called the ________

Back 73

lumen

Front 74

Microtubules also have a ____ end and a _____ end, and assembly/disassembly takes place at the ____ end

Back 74

plus, minus
plus

Front 75

are spindle fibers microfilaments or microtubules?

Back 75

microtubules

Front 76

Microtubules radiate outward from the ______

Back 76

nucleus

Front 77

axons and neurons are made of ______

Back 77

microtubules

Front 78

Cilia and flagella are formed from _______

Back 78

microtubules

Front 79

microvilli are formed from ______

Back 79

microfilaments

Front 80

what are 3 differences between intermediate filaments and microtubules/microfilaments

Back 80

They don't have a plus/minus end, not dynamic (stable), and are cell-specific

Front 81

Do plants have intermediate filaments?

Back 81

NO

Front 82

What is an intermediate filament formed from?

Back 82

8 protofilaments twisted together

Front 83

Which assembly is the most complex? microfilament, intermediate filaments, or microtubules?

Back 83

intermediate filaments

Front 84

Name some jobs of intermediate filaments

Back 84

stable support of the cytosol, nuclear support and organization of chromatin and nuclear pores, form connections to intercellular jxns, form the connections between muscle filament bundles

Front 85

Which part of the cytoskeleton can be used as an anchor?

Back 85

intermediate filament

Front 86

nuclear scaffold is composed of intermediate filaments also known as (in this situation) the ______ _____

Back 86

lamin filament

Front 87

skeletal muscle has many _____ ______

Back 87

intermediate filaments

Front 88

sacomere support in striated muscle is bundled in what way?

Back 88

contractile

Front 89

The thick filament in muscle contraction is made of _____

Back 89

myosin

Front 90

A homolog refers to....

Back 90

a common structure, common function
(a bird and a bat wing have a similar structure and a similar fxn)

Front 91

an analog refers to....

Back 91

a common function , different structure
(butterflys and birds have different wings, but they are both used for flying)

Front 92

the bacterial homolog to actin is:
analogous to tubulin

Back 92

ParM

Front 93

bacterial homolog to Tubulin:
analogous to actin

Back 93

FtsZ

Front 94

For microfilaments, the motor protein is called....

Back 94

myosin

Front 95

for microtubules the motor proteins are called....

Back 95

kinesin, dynein

Front 96

_____ and _____ working together perform the same function as the microfilament motor protein, myosin

Back 96

kinesin, dynein

Front 97

Myosin moves along the ______. Can it move one direction or two, and if one direction, which direction?

Back 97

microfilament, can move both directions

Front 98

Kinesin moves along the ______. Can it move one direction or two, and if one direction, which direction?

Back 98

microtubule, moves only toward the positive end
(away from the MTOC)

Front 99

Dynein moves along the ______. Can it move one direction or two, and if one direction, which direction?

Back 99

microtubule, moves only toward the negetive end
(toward from the MTOC)

Front 100

Polymerization is the same as assembly. Its just that _____ is a mechanism, while _____ is a process

Back 100

polymerization, assembly

Front 101

What are the two mechanisms of dis-assembly?

Back 101

depolymerization and severing

Front 102

What do Thymosin and Profilin regulate?

Back 102

speed of polymerization in microfilaments

Front 103

what does ARP stand for?

Back 103

Actin related protein

Front 104

ARP does what?

Back 104

aids in the polymerization of microfilaments (on an existing microfilament)

Front 105

Which protein is used to create the 70 degree angle in a gel-like bundling of microfilaments?

Back 105

ARP

Front 106

______ binds to a small aggregate of ATP-actin to facilitate nucleation and cause rapid polymerization

Back 106

Formin

Front 107

Formin can only attach to an already formed _____ of ______

Back 107

aggregate of actin

Front 108

If a pot was placed on the side of a tree, and another tree grew out of it at an angle, what is that similiar too?

Back 108

ARP being placed in the middle of a microfilament, and then the new filament grows from that ARP

Front 109

What regulates the speed of microfilament assembly?

Back 109

profilin, and thymosin

Front 110

Profilin will never bind to what?

Back 110

An ADP actin (no E)

Front 111

Thymosin does what?

Back 111

Inhibits or slows down ATP-actin polymerization

Front 112

caps for microfilaments attach to the _____ end to stabilize the microfilament

Back 112

plus end

Front 113

capping prevents both ______ and _______

Back 113

polymerization and de-polymerization

Front 114

microfilament associated proteins promote _______

Back 114

bundling

Front 115

_________ extend from the plasma membrane and are formed from microfilaments

Back 115

microvilli

Front 116

What is the function of microvilli?

Back 116

To increase surface area of a cell, which in turn increases absorption

Front 117

Which protein is used for microfilament severing?

Back 117

Gelsolin

Front 118

Which protein is used for microfilament de-polymerization?

Back 118

Cofilin

Front 119

Which monomer does cofilin bind to?

Back 119

ADP-actin
(on the negetive end)

Front 120

What is the fxn of an ATP-cap on a microfilament?

Back 120

It favors polymerization

Front 121

What is a contractile ring and what is it made of?

Back 121

it is a group of microfilaments used in cytokinesis to divide a cell in half

Front 122

What are the two types of disassembly for microtubules?

Back 122

severing and depolymerization
(same as microfilaments)

Front 123

Difference between nucleation of microtubules and microfilaments?

Back 123

nucleation of microfilaments can occur from a spontaneous aggregate or a pre-existing microfilament, while microtubule nucleation MUST occur in a MTOC (microtubule organizing center)

Front 124

What is the microtubule equivelent to microfilament's ARP?

Back 124

gamma-Tubulin ring complex
(anchors onto the membrane of the MTOC)

Front 125

Exons are formed from ______ _______

Back 125

basal bodies

Front 126

The equivalent of both profilin and thymosin is _______ ,in microtubules

Back 126

stathmin

Front 127

role of stathmin?

Back 127

stathmin protein will bind free tubulin subunits and inhibit assembly and elongation

Front 128

Stathmin that is un-phosphorylated can bind to tubulin and ________ assembly

Back 128

inhibits
(acts like thymosin)

Front 129

Stathmin that is phosphorylated no longer binds to tubulin, which does what?

Back 129

allows free tubulins to be free to polymerize

Front 130

How do you free tubulin from stathmin?

Back 130

by phosphorylating stathmin, which inactivites stathmin, allowing tubulin to polymerize

Front 131

How is stathmin regulated?

Back 131

By the kinase which phosphorylates stathmin

Front 132

Is there an equivelent of actin capping proteins for microtubules?

Back 132

No, there are no microtubule caps
BUT there are +TIP proteins

Front 133

What's a TIP protein

Back 133

a + end tracking protein
(binds to the side of a microtubule near the + end

Front 134

What are MAP2 and tau?

Back 134

They are TIP proteins that stabilize the microtubules and bind to the side of the microtube near the plus end. They inhibiting depolymerization
(depolymerization may still occur), but do not prevent polymerization

Front 135

the microtubule GTP cap promotes _____

Back 135

polymerization

Front 136

Does MAP2 and tau promote polymerization?

Back 136

no, it neither promotes nor inhibits

Front 137

Depolymerization of microtubules is done by ______

Back 137

the catastrophe factor

Front 138

the catastrophe factor is analogous to

Back 138

microfilament's cofilin

Front 139

can stathmin bind to free tubulin and bound tubulin?

Back 139

yes (while profilin and thymosin can only bind to free actin) (also, can bind to GTP or GDP tubulin)

Front 140

What is Katanin?

Back 140

Katanin is a severing protein for microtubules
(samurai sword)

Front 141

is assembly of intermediate filaments fast or slow?

Back 141

slow (very stable)

Front 142

Intermediate filaments are composed of 8 _______ twisted into a ropelike filament

Back 142

dimers

Front 143

Most of the intermediate filament regulation occurs by _______ _______

Back 143

covalent modification

Front 144

What are the two types of covalent modification used to regulate intermediate filaments? which is most common?

Back 144

Glycosylation and phosphorylation (<-most common)

Front 145

when lamin is in the the _______ form, lamin have an affinity for one another (which almost spontaneously forms a nuclear scaffold)

Back 145

unphosphorylated form

Front 146

when the nuclear scaffold breaks down, the ______ breaks down

Back 146

nucleus

Front 147

how can you break down a nucleus?

Back 147

by phosphorylating lamin, which initiates break down of nuclear scaffold

Front 148

cell adhesion is?

Back 148

cells interacting with other cells and with the extracellular matrix

Front 149

What are the 4 types of junctions?

Back 149

Anchoring junction, occluding junction, channel-forming junction, signal relaying junctions

Front 150

all junctions require a ________ ________ protein

Back 150

transmembrane adhesion protein

Front 151

There are two types of cell-cell jxns and two types of cell-matrix junctions...what is the difference between them?

Back 151

They have different functions

Front 152

what is another term for actin-linked-cell-matrix adhesions?

Back 152

focal adhesion (focal contact)

Front 153

Where is the only place you can find a hemidesmosome?

Back 153

In between an epithelial cell and a basil lamina

Front 154

What is the stability level of hemidesmosomes?

Back 154

very stable

Front 155

What is the transmembrane protein in a hemidesmosome?

Back 155

Integrin

Front 156

what is integrin?

Back 156

the transmembrane protein in a hemidesmosome

Front 157

What does integrin bind to?

Back 157

Laminin
(major component of basil lamina)

Front 158

intracellular anchoring proteins...name 2 examples
(found on hemidesmosome)

Back 158

dystonin, plectin,

Front 159

Integrin binds to an _____ _____ named ______ as an anchor in hemidesmosomes

Back 159

intermediate filament, keratin

Front 160

What do intracellular anchoring proteins do?

Back 160

They are the medium between the transmembrane protein and the intermediate filament used for anchorage.

Front 161

What is linked recognition?

Back 161

Where the cytosolic domain and the non-cytosolic domain "talk to each other" via the transmembrane protein (binding of 1 side causes a conformational change that will induce binding of the other side)

Front 162

What is a hemidesmosome?

Back 162

a cell-matrix junction that anchors on an intermediate filament

Front 163

What is the difference between a transmembrane protein binding to a intermediate filament vs a microfilament?

Back 163

Intermediate filaments are more stable unlike dynamic microfilaments. IF's make better anchors

Front 164

Hemidesmosomes provide ____/______ strength to the tissue

Back 164

mechanical/tensile

Front 165

Are focal adhesions more flexible or more stable?

Back 165

flexible

Front 166

Integrin binds to collagen in what types of adhesion?

Back 166

focal adhesion (cell-matrix jxn)

Front 167

What is collagen's role within adhesion?

Back 167

Collagen is the ECM protein that integrin binds to in focal adhesion, while the cytosolic domain binds to a microfilament

Front 168

Integrin only acts as a ______-______

Back 168

hetero-dimer
(2 different kinds of integrin)

Front 169

cell to cell adhesion comes from a __________
(attaches to an intermediate filament

Back 169

desmosome

Front 170

Cadherin binds via _________ binding

Back 170

homophillic

Front 171

For desmosomes in cell-cell interactions, what is the transmembrane attach to on the cytosolic sides?

Back 171

intermediate filaments

Front 172

For desmosomes in cell-cell interactions, what is the transmembrane protein?

Back 172

cadherin

Front 173

For cell-cell interactions that bind to microfilaments, what is the transmembrane protein called?

Back 173

cadherin

Front 174

Why is there a whole family of cadherins?

Back 174

Because there are different cadherins specific to cell type. This allows certain types of cadherrins to only attach to each other, therefore allowing adhesion of alike cells.

Front 175

Claudin and Occuldin only perform which kind of binding?

Back 175

Homophillic. Claudin will bind to Claudin , and Occuldin to Occuldin

Front 176

What proteins are found in tight junctions?

Back 176

Claudin and Occuldin

Front 177

What is the function of tight junctions?

Back 177

Tight Junctions can block molecules as
small as ions from passing between cells
(prevent leaking of epithelium)
`

Front 178

Integrin can help 2 cells interact through a process called ______ ______

Back 178

rolling adhesion

Front 179

Blood cells use _____ _____ to get to cells it needs to be at, such as a wound

Back 179

rolling adhesion

Front 180

P-selectin and I-Cam, do what?

Back 180

they are adhesion proteins that help with rolling adhesion

Front 181

P-selectins bind to ?

Back 181

Carbohydrates on white blood cells, but they bind weakly so they just slow down the cell

Front 182

Integrin on white blood cells binds to?

Back 182

ICam or NCam (during rolling adhesion)

Front 183

After a vesicle departs from the trans cisterna of the Golgi, it goes to the plasma membrane or ______

Back 183

a lysosome

Front 184

Lysosomes do what?

Back 184

Break down (recycle) material

Front 185

What are bound ribosomes?

Back 185

ribosomes that have docked onto the cytosolic side of the ER membrane

Front 186

What tells ribosomes whether they should be bound or not?

Back 186

Topogenic sequences

Front 187

What proteins are made from free ribosomes?

Back 187

cytoskelton materials (actin, tubulin intermediate filament proteins, myosin, kinesin, dynein, etc) as well as 2nd messengers for signaling cascades and glycolysis enzymes

Front 188

What proteins are made from bound ribosomes?

Back 188

Signal Receptors, Transporters, Channels ,Cadherins, Integrins, Anchor protein complexes ,Enzymes inside organelles, Secreted proteins

Front 189

What are 3 principle functions of the ER?

Back 189

Lipid biosynthesis, membrane bound translation of mRNA, initial integration of lipids and proteins

Front 190

Information on the amino terminus of proteins is read by _______/_______ to determine where they go

Back 190

ribosomes/chaperonins

Front 191

Name the 4 major events of vesicular transport

Back 191

Budding, Transport , Targeting and Fusion

Front 192

What are the 3 things proteins recognize to before budding can occur?

Back 192

lipid signature, protein signature and cytosolic protein meshwork

Front 193

Coat protein recognizes ______ on membrane and promotes _____

Back 193

signatures, budding

Front 194

The coat protein sheds to do what?

Back 194

So expose the naked vesicle so that the signatures can be read

Front 195

COPII is a coat protein that transports vesicles from teh ____ to the _____

Back 195

ER-->Golgi

Front 196

COPI is a coat protein that transports vesicles from the ____ to _____

Back 196

cis-cisterna to other areas of the Golgi

Front 197

What are the 2 proteins found on all vesicles that are used in targeting?

Back 197

v-SNARE and Rab-GTP

Front 198

What is the function of a v-SNARE?

Back 198

to bind (to hang on tightly) to the target protein (t-SNARE)

Front 199

What does the RAB protein do on a docking vesicle?

Back 199

It attaches to a RAB effector and bends it downward, then the SNARE's bind

Front 200

What is clathrin?

Back 200

A coat protein

Front 201

Dynamin does what?

Back 201

Severs the neck of a budding vesicle

Front 202

Removing coat proteins is a process called _____

Back 202

uncoating

Front 203

3 different types of coat proteins....

Back 203

COPII, COPI and clathrin

Front 204

What does a molecular motor recognize on a vesicle?

Back 204

The cytosolic protein meshwork (very thick so a lipid signature cannot be found)

Front 205

How does fusion occur?

Back 205

Fusion of two membranes depends on a good match between the lipids. Almost spontaneous. similiar lipids will mix (vegetable oil and peanut oil will mix)

Front 206

Which cisterna of the Golgi is used to sort proteins?

Back 206

The trans-ciserna

Front 207

Most important process within the Golgi

Back 207

Glycosylation

Front 208

Constitutive secretory pathway is _______ secreted

Back 208

always

Front 209

Regulatory secretory pathways are ________ whiled waiting for a signal to release the vesicle

Back 209

stored

Front 210

What is co-translation?

Back 210

Where two proteins that have the same function and similiar structure are processed and transported together, yet translation initiation is independant

Front 211

Lysosomes have what pH?

Back 211

pH 5 (slightly acidic), rest of cell is 7

Front 212

Lysosome's proton gradient relies on what to lower it's PH?

Back 212

the proton pump combined with the E from ATP

Front 213

what organelle has to do with the endosymbiotic theory?

Back 213

the mitochondria

Front 214

True or False? Not all mitochondial proteins are encoded in mitochondrial DNA

Back 214

TRUE, some are encoded in nuclear DNA

Front 215

How are proteins embedded into the inner membrane of the mitochondria?

Back 215

TOM and TIM. TOM grabbs a protein from the cytosol, and then TIM embeds the protein into the inner membrane

Front 216

Can proteins brought into the mitochondrial membrane, ever leave?

Back 216

nope