Cell Structure 1

Question 1

glycocaylx

Answer 1

external layer of the lipid bilayer, glycoproteins and glycolipds may have carbohydrates covalently attached.
Function: cell-to-cell and cell-to-extracellular matric recognition.

Question 2

microtubules (MTs)

Answer 2

• made out of dimers (alpha, beta)
• dynamically instable
• growth happens more at the (+) end (polarized)
• Make up mitotic spindle
• serve as cell railways
• determinant of cell shape
• core of Cilia and flagella
• component of basal bodies and centrioles

Question 3

kinesin

Answer 3

motor protein. moves on MTs from (-) to (+) end

Question 4

dynein

Answer 4

motor protein. moves on MTs from (+) to (-) end

Question 5

centrisome

Answer 5

microtuble organizing center (MTOC). (-) ends are anchored to MTOC

Question 6

basal bodies

Answer 6

made up of 9 microtubule triplets. body of cilia and flagella

Question 7

Motile Cilia and Flagella

Answer 7

Core of 9 doublets plus 2 core singlets (MTs)

• Dynein arms
• Nexin connectors
• radial spokes to center

Question 8

Axoneme

Answer 8

Structural core of cilia and flagella

Question 9

primary cilia

Answer 9

core of 9 doublets with no center core (MTs)

• establish left-right asymmetry
• single cilia

Question 10

Intermediate Filaments

Answer 10

• rod like coiled dimers
• used as a marker to determine the tissue source of the origin of tumor cells.
• anchored to desmosomes

Question 11

Microfilaments

Answer 11

aka Actin

• dynamic and polarized
• motor protein myosins
• part of cell cortex (gives shape to cell)
• forms the core and body of microvilli
• aids in zonula and fascia adherens juntions
• provide cell movement
• separates daughter cells.

Question 12

tight junctions

Answer 12

zonula occludens

• belt like structure around cell
• most apical
• transmembrane proteins seal the juntion

Question 13

adhering junction

Answer 13

desmosomes
zonula adherens
hemidesmosome

• uses actin or IFs to connect to cytoskeleton
• Adaptor proteins- anchor CAMs to cytoplasmic domain
• Cell adhesion molecules (CAMs)- bind cell to lamina or cell to cell

Question 14

Zonula adherens

Answer 14

adhering junction

• Continuous belt-like
• CAMs- E-cadherin
• adaptor proteins- vinculin, catenin, and alpha-actinin

Question 15

Macula Adherens

Answer 15

Desmosome

• Adaptor proteins- desmoplakin and plakoglobins
• third highest on apical side of epithelia

Question 16

Hemidesmosome

Answer 16

• anchor IFs to cells
• anchors cell to basal lamina
• CAMs- integrin and Type XVII collagen
• adaptor proteins- plectin, erbin and bpag1

Question 17

Gap Junctions

Answer 17

aka Nexus
small acqueous channels that allow ions and small molecules to pass between cells
connexin units form a single connexon unit