lecture 2

Question 1

ECM consistency

Answer 1

• proteoglycans
• insoluble protein fibres (collagen, laminin, elastin)

Question 2

3 types of cell junctions

Answer 2

Gap junctions
Tight junctions
Anchoring junctions

Question 3

Gap junctions

Answer 3

communicating junctions (between cytoplasms of adjacent cells)

proteins: connexin proteins

Question 4

Tight junctions

Answer 4

occluding junctions. adjacent membranes are partly fused together to make a barrier

protein: claudin and occludin proteins

Question 5

Anchoring junctions

Answer 5

anchor cells to each other or ECM. provides strength when tissue is under mechanical stress

protein: cadherin proteins

Question 6

anchor junctions:
cell-cell
cell-ECM

Answer 6

desmosome= cell-cell
hemidesmosome= cell-ECM

Question 7

4 major tissue types in the body

Answer 7

Epithelial
Connective tissue cells
Muscle
Neural

Question 8

Epithelial tissue: function, cell types

Answer 8

protects internal environment of the body, regulates exchange of materials between internal/external environment

cell types: exchange, protective, ciliated, transporting, secretory

Question 9

Connective tissue cells

Answer 9

provides structural support and physical barriers

• found in extracellular matrix networs

cell types: blood cells, bones cells, fibroblasts

Question 10

Muscle tissue

Answer 10

generates contractile force

cell type: smooth, skeletal, cardiac

Question 11

Neural

Answer 11

Neurons –> information transfer (chemical/electrical)

Glial cells –> support for neurons

Question 12

5 functions of epithelial cells

Answer 12

1. exchange
2. protective
3. ciliated
4. transporting
5. secretory

Question 13

what does the consistency of tissue depend on?

Answer 13

the type of tissue

Question 14

6 types of connective tissue

Answer 14

1. loose connective tissue
2. dense connective tissue
3. adipose tissue
4. blood
5. cartilage
6. bone

Question 15

what is the difference between loose and dense connective tissue?

Answer 15

loose= elastic tissue beneath the skin and between some cells

dense= provides strength and flexibility
(tendons and ligaments)

Question 16

what 2 tissue types are excitable?

Answer 16

Muscle tissue and Neural tissue

(able to generate and transmit electrical signals. minimal extracellular matrix)

Question 17

cell membrane permeability

Answer 17

selectively permeable

transport depends on composition of lipid/protein

increased membrane cholesterol = decreased h2O permeability

Question 18

membrane permeability is directly correlated to

Answer 18

lipid solubility/molecular size

Question 19

facilitated transport of a substance

Answer 19

may require a channel or transporter

may require use of ATP

Question 20

different membrane transport mechanisms

Answer 20

Non faciliated transport
(simple diffusion)

Facilitated transport
–> protein mediated transport (channels, transporters)
active, passive

–> vesicular transport (endocytosis, exocytosis, phagocytosis)

Question 21

simple diffusion

Answer 21

directly across a phospholipid bilayer.
small lipophilic molecules

Question 22

facilitated diffusion is a type of

Answer 22

protein-mediated transport

Question 23

Fick’s law of diffusion

Answer 23

rate of diffusion is directly related to:

surface area x concentration gradient x membrane permeability

Question 24

membrane permeability equation

Answer 24

membrane permeability is directly related to lipid solubility/molecular size

Question 25

8 roles of proteins in the body

Answer 25

1. structure 2. enzymes 3. membrane transporter 4. receptors 5. signal molecules 6. binding proteins 7. immunoglobulins 8. regulatory proteins

Question 26

2 main types of protein-mediated transport

Answer 26

facilitated diffusion (passive)= down conc gradient active transport (ATP input)= against conc gradient, system moves away from equilibrium

Question 27

Channels

Answer 27

facilitated diffusion, ALWAYS passive selective: small molecules, water channels, ions channels fast transport can have gates

Question 28

Carriers or transporters

Answer 28

open to either one side of the membrane or the other facilitated diffusion OR active transport can be selective slower than channels

Question 29

4 types of channels

Answer 29

1. passive/leak channels 2. voltage gated 3. ligand gated 4. mechanically gated

Question 30

what does channel selectivity depend on?

Answer 30

the diameter of the pore the electrical charge of amino acids lining the pore

Question 31

3 types of carrier proteins

Answer 31

Uniport= one substrate in one direction Symport= two substrate in one direction Antiport= substrates in opposite directions

Question 32

Transcellular transport

Answer 32

transport through simple diffusion, facilitated diffusion, active transport, endo/exocytosis ions or molecules cross both apical and basolateral membranes

Question 33

Paracellular transport

Answer 33

molecules pass between adjacent cells to get to or from lumen regulated by the presence of tight junctions