Cell Biology

Question 1

What is the name of the theoretical model for the plasma membrane?

Answer 1

Modified fluid-mosaic model

Question 2

What are the surface molecules on cells that establish the extracellular microenvironment?

Answer 2

Glycocalyx

Question 3

What type of integral membrane protein anchors the extracellular matric to the intracellular cytoskeleton?

Answer 3

Linker proteins

Question 4

What characteristics describe molecules that can diffuse through the cell membrane?

Answer 4

Small, lipid soluble, or uncharged molecules

Question 5

What classes of proteins facilitate membrane transport?

Answer 5

Carrier and channel proteins

Question 6

What regulates membrane transport by channel proteins?

Answer 6

Membrane potentials, neurotransmitters, or mechanical stress

Question 7

What are the two exocytosis pathways? What is the primary difference between them?

Answer 7

Constitutive and Regulated-secretory pathway; Proteins that are constantly secreted go through the constiutive pathway while the regulated secretory pathway is triggered by a stimulus

Question 8

What is pinocytosis?

Answer 8

The nonspecific uptake of fluid and small molecules by small vesicles

Question 9

OF pinocytosis and phagocytosis, which is receptor-mediated?

Answer 9

Phagocytosis

Question 10

What are the membrane-bound compartments in the cell formed by endocytotic pathways?

Answer 10

Endosomes

Question 11

What is unique about the membrane of lysosomes?

Answer 11

It is resistant to hydrolysis

Question 12

What are the functions of the rough endoplasmic reticulum?

Answer 12

Site of protein synthesis and post-translatonal modification of newly synthesized proteins

Question 13

What type of proteins are synthesized in the rough endoplasmic reticulum?

Answer 13

Secreted and integral membrane proteins

Question 14

What serves as the principal organelle for detoxification in hepatocytes?

Answer 14

Smooth Endoplasmic Reticulum

Question 15

The smooth endoplasmic reticulum is abundant in cells with what charateristic?

Answer 15

High lipid metabolism

Question 16

What are the flattened membrane-limited sacs within the Golgi apparatus?

Answer 16

Cisternae

Question 17

What are the cisternae of the Golgi apparatus farthest away from the rER?

Answer 17

Trans-Golgi Network

Question 18

What are the functions of the Golgi Apparatus?

Answer 18

Post-translational modification of proteins, sorting, packaging of proteins

Question 19

What are the four major pathways of protein secretion via the Golgi apparatus?

Answer 19

Constitutive pathway to apical plasma membrane and to basolateral plasma membrane, endosomes and lysosomes, and regulated pathway

Question 20

In which golgi pathway of protein secretion are proteins stored in secretory vesicles, which mature, fuse with plasma membrane to release their contents?

Answer 20

Regulated pathway

Question 21

What types of cells do not have mitochondria?

Answer 21

RBCs and terminal keratinocytes

Question 22

What ar e the three major functions of the mitochondria?

Answer 22

Oxidation reactions of the electron transport chain, synthesis of ATP, regulates transport of metabolites in and out of matrix

Question 23

What is the neame of the folds of the inner mitochondrial membrane?

Answer 23

Cristae

Question 24

What phospholipid is rich in the inner mitochondrial membrane and makes it impermeable to ions?

Answer 24

Cardiolipin

Question 25

What type of enymes are contained within the peroxisomes?

Answer 25

Oxidative enzymes

Question 26

What is the function of catalases in the peroxisome?

Answer 26

Breakdown of hydrogen peroxide

Question 27

What kind of cytoskeletal fiber is the smallest?

Answer 27

Actin

Question 28

What kind of actin is polymeried? Unpolymerized?

Answer 28

F-actin; G-actin

Question 29

Which end of actin filament is fast growing?

Answer 29

Plus end

Question 30

What is actin filament growth dependent on? What other chemical species are required for polymerization?

Answer 30

Dependent on local concentrations of G-actin and ABPs; K+, Mg++, and ATP

Question 31

What are the functions of actin filaments?

Answer 31

Anchorage and movement of membrane proteins, microvilli structural core, cell locomotion, extension of filopodia

Question 32

What is the most abundant intermediate filament?

Answer 32

Vimentin

Question 33

What type of intermediate filament is found especially in muscle cells?

Answer 33

Desmin

Question 34

How is keratin from adjacent cells connected?

Answer 34

Desmosomes

Question 35

What intermediate fibers are especially associated with the nuclear envelope

Answer 35

Lamins

Question 36

What are microtubules composed of?

Answer 36

Alpha- and beta-tubulin dimers

Question 37

Which end of the microtubule corresponds to alpha-tubulin and the MTOC?

Answer 37

minus end

Question 38

What are the functions of microtubules?

Answer 38

Intracellular vesicle transport, movement of cilia and flagella, attachment of chromosomes to mitotic spindle, cell elongation and movement, maintenance of cell shape

Question 39

What type of motor protein moves toward the minus end of the microtubule?

Answer 39

Dyneins

Question 40

What are centrioles composed of?

Answer 40

9 micotubule triplets

Question 41

What does the microtubule-organzing center contain?

Answer 41

Centrioles and the pericentriolar material

Question 42

What type of tubulin serves as the nucleation site for new microtubules?

Answer 42

Gamma tubulin

Question 43

What are the functions of centrioles?

Answer 43

Development of cilia and mitotic spindle organization

Question 44

Where do microtubules connect to chromosomes?

Answer 44

Kinetochore

Question 45

What is the action of colchicine? What is it used to treat?

Answer 45

Prevents microtubule polymerization and ergo cell division; gout

Question 46

What is the action fof vincristine? What is it used to treat?

Answer 46

Inhibits formation of the mitotic spindle; cancer

Question 47

What is the effect of taxol? What is it used to treat?

Answer 47

Stabilizes and prevents depolymerization of microtubules; cancer

Question 48

What type of inclusion is a conglomerate of lipids, metals, and organic molecules?

Answer 48

Lipofuscin

Question 49

What type of inclusion is an iron-storage complex?

Answer 49

Hemosiderin

Question 50

What part of nucleolus contains DNA of five chromosomes, RNA pol I and transcription factors?

Answer 50

Fibrillar center

Question 51

What part of the nucleolus is the site of initial ribosome assembly ?

Answer 51

Granular material

Question 52

What structure mediates bidirectional nucleo-cytoplasmic transport?

Answer 52

Nuclear Pore Complex

Question 53

What are the phases of mitosis?

Answer 53

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

Question 54

In which mitotic phase do daughter chromosomes separate?

Answer 54

Anaphase

Question 55

What are the phases of prophase I of meiosis I?

Answer 55

Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis

Question 56

In which phase of prophase I does recombination occur?

Answer 56

Pachytene

Question 57

What form of cell death triggers a strong inflammatory response?

Answer 57

Necrosis

Question 58

What are the structural characteristics of apoptosis?

Answer 58

DNA fragmentation, membrane blebbing, formation of apoptotic bodies