August 22- Introduction

Question 1

what are parenchyma cells

Answer 1

they make up the functional elements of an organ

Question 2

what are stroma cells

Answer 2

structural framework of an organ, background tissue

Question 3

what are the 5 basic tissue types

Answer 3

blood, connective tissue, epithelium, muscle, nervous tissue

Question 4

describe blood tissue

Answer 4

only fluid tissue, contained within vessels of circulatory system

Question 5

describe connective tissue

Answer 5

surrounds and supports other tissue

ex: stroma

Question 6

describe epithelial tissue

Answer 6

covers body surfaces, lines cavities and forms glands

ex: skin, liver, lining of gut

Question 7

describe muscle tissue

Answer 7

contains specialized contractile cells responsible for movement

Question 8

describe nervous tissue

Answer 8

contains modified cells responsible for intracellular communication

Question 9

what happens to unfixed tissues (unprepared tissues)

Answer 9

they denature

Question 10

what is used to preserve tissue cells and how

Answer 10

formalin (37% formaldehyde) through cross-linking of proteins

Question 11

whats the next step after fixing the tissue with formalin

Answer 11

place cut tissue in cassettes and dehydrate via a series of alcohol baths and clear with xylene

Question 12

why do you need to dehydrate the cell

Answer 12

to be able to penetrate the cell

Question 13

why must the tissue be embedded in liquid paraffin or plastic resin

Answer 13

so the tissue doesnt fall apart

Question 14

why do you have to rehydrate the tissue

Answer 14

to stain it

Question 15

explain the steps of tissue preparation

Answer 15

fix with formalin

• place tissue in cassettes
• dehydrate
• embed in paraffin or plastic
• microtome or grind
• mount on slide
• remove paraffin
• rehydrate
• stain
• coverslip

Question 16

what does hemotoxylin do

Answer 16

a blue, basic dye; stains acids. basophilic

Question 17

what does eosin do

Answer 17

red-pink, acidic dye;stains bases (proteins) - eosinophilic

Question 18

what makes up the electron dense later on EM

Answer 18

phospholipid heads

Question 19

what makes up electron lucent layer

Answer 19

FA tails

Question 20

what do hydrophilic heads contain

Answer 20

+ charged N groups and - charged phosphate groups, present on inside and outside of membrane

Question 21

what does the hydrophobic portion contain

Answer 21

two long chain FA’s covalently linked to glycerol

Question 22

describe the fluid mosaic model

Answer 22

fluidity of membrane increases with increased temperature and decreased saturation of FAs

Question 23

how does cholesterol affect the phospholipid bilayer (cell membrane)

Answer 23

increased cholesterol decreases fluidity

Question 24

what are extrinsic or peripheral proteins

Answer 24

proteins on surface of membrane

Question 25

what are intrinsic or integral proteins

Answer 25

proteins within the membrane

Question 26

what are transmural or transmembrane proteins

Answer 26

proteins that extend from one side of the membrane to the other

Question 27

what are pores

Answer 27

openings in transmembrane proteins that stay open all the time

Question 28

what are channels

Answer 28

transmembrane proteins that can open and close

Question 29

what do pumps do

Answer 29

transport ions across membrane

Question 30

what do channels do

Answer 30

allow passage of water soluble molecules via diffusion

Question 31

what do receptor proteins do

Answer 31

allow for cell recognition and binding on cell membrane

Question 32

what do transducers do

Answer 32

initiate enzymatic reactions following binding with ligand molecules

Question 33

what do enzymes do

Answer 33

components of ion pumps and digestive action

Question 34

what do structural proteins do

Answer 34

add mechanical stability to the membrane

Question 35

what is a glycocalyx

Answer 35

membrane proteins and some lipids are conjugated with short polysaccharide chains containing glucose molecules such as glycoproteins and glycolipids

Question 36

what is the purpose of the glycocalyx

Answer 36

• protects surface of cell membrane
• may be involved in cell recognition
• mediates exchange between internal and external cell environment

Question 37

what are the 4 types of transport

Answer 37

-simple (passive) diffusion
-facilitated diffusion
active transport
bulk (vesicular) transport

Question 38

what molecules use simple diffusion

Answer 38

lipids, gases some small hydrophilic molecules

Question 39

what is facilitated diffusion

Answer 39

passive and concentration dependent but requires carrier molecules

Question 40

what is another name for facilitated diffusion

Answer 40

carrier mediated diffusion

Question 41

what molecules use facilitated diffusion

Answer 41

water soluble hydrophilic molecules (glucose, amino acids)

Question 42

what are aquaporins

Answer 42

type of channel that uses facilitated diffusion, allows water to cross plasma membrane faster than simple diffusion

Question 43

how can passive and facilitated diffusion be enhanced

Answer 43

by increased surface area of cell membrane folding

Question 44

where does active transport occur

Answer 44

dynamic pore sites (usually transmembrane proteins)

Question 45

what is bulk (vesicular) transport

Answer 45

active transport that involves the engulfment of molecules or particles aka endocytosis

Question 46

what is receptor mediated endocytosis

Answer 46

extracellular molecules (ligands) bind to receptor proteins, or clathrins, located in coated pits of cell membrane

Question 47

what is transcytosis

Answer 47

transport of material across or through cell via sequential endocytosis followed by exocytosis