chapter three

Question 1

membranes

Answer 1

fundamental component that makes a cell a cell, defines inside of cell from outside of cell, tissues that line a cavity, separate the cellular interior from extracellular environment

Question 2

what are the functions of the cell (plasma) membrane or plasmalemma?

Answer 2

physical barrier, gateway for exchange, communication, cell structure

Question 3

physical barrier

Answer 3

separates intracellular fluid and extracellular fluid

Question 4

gateway for exchange

Answer 4

regulates exchange between intracellular compartments and interstitial fluid

Question 5

communication

Answer 5

signals surrounding cells and senses extracellular environment

Question 6

cell structure

Answer 6

anchor cytoskeleton, form tissues

Question 7

what can substances move through?

Answer 7

non-polar molecules (fatty acids, vitamins A, D, E, K, steroids), oxygen, carbon dioxide, water

Question 8

what can substances not move through?

Answer 8

ions (sodium, potassium, calcium, hydrogen), polar molecules (polysaccharides, amino acids, glucose, nucleic acids)

Question 9

is water polar or non-polar?

Answer 9

polar

Question 10

integral

Answer 10

any protein that is physically embedded in the membrane

Question 11

transmembrane (integral)

Answer 11

all transmembrane proteins are integral, but not all integral are transmembrane

Question 12

peripheral

Answer 12

not integral, not transmembrane, closely associated with the membrane but not embedded in membrane

Question 13

what are eukaryotic cells?

Answer 13

human cells

Question 14

where are eukaryotic cells divided?

Answer 14

on the inside with organelles

Question 15

cell theory

Answer 15

cell is made of many different components

Question 16

cytosol

Answer 16

the semi-liquid portion of the cytoplasm not occupied by organelles

Question 17

cytoplasm

Answer 17

the interior of a cell other than the nucleus

Question 18

nucleus

Answer 18

internal organelle that contains the genetic material for cellular reproduction

Question 19

mitochondria

Answer 19

“powerhouse of the cell”; a double-membrane organelle that produces the ATP through oxidative phosphorylation (membrane bound structure)

Question 20

endoplasmic reticulum

Answer 20

flat series of membrane layers that specializes in secretion of substances

Question 21

rough (granular) ER

Answer 21

has ribosomes on the surface for protein synthesis, molecules enter ER and are packed for secretion from the cell (neurotransmitter & hormones) (make & secrete proteins)

Question 22

smooth (agranular) ER

Answer 22

no ribosomes, used for sorting of molecules, specializes in lipid synthesis, calcium storage, makes lipids (steroids)

Question 23

Golgi complex

Answer 23

set of flat, stacked, membranous sacs that process raw material transported from the ER into finished products, sorts and directs the finished product to their final destination

Question 24

cytoplasmic vesicles

Answer 24

lysosomes, peroxisomes, transport vesicles

Question 25

lysosomes

Answer 25

contain enzymes that breakdown foreign invaders, other organelles, proteins, carbohydrate (CHO), some fats, serves for cell digestion & secretion

Question 26

peroxisomes

Answer 26

breakdown fatty acids & amino acids using oxidative enzymes (produces hydrogen peroxide)

Question 27

transport vesicles

Answer 27

used in storage & transport of substances

Question 28

cellular inclusions

Answer 28

non-membrane structures within the cytoplasm

Question 29

what are the cellular inclusions?

Answer 29

ribosomes, proteasome, vaults

Question 30

ribosomes

Answer 30

not membrane bound, granules of RNA and protein, translates mRNA into proteins

Question 31

proteasomes

Answer 31

small protein complex that destroys proteins

Question 32

vaults

Answer 32

small complex of RNA and proteins resembling octagonal barrels, exact function unclear (maybe related to movement around itself)

Question 33

what composes the cytoskeleton?

Answer 33

cytoplasmic protein fibers

Question 34

cytoplasmic proteins

Answer 34

assist eukaryotic cells in their overall shape, organization, transport and movement

Question 35

microfilaments

Answer 35

(actin & myosin) mechanical stiffener for microvilli, important in contractile systems

Question 36

microvili

Answer 36

finger like projections that increase the surface area of a cell

Question 37

contractile systems

Answer 37

muscle

Question 38

intermediate filaments

Answer 38

(myosin, keratin) structural support in cells subject to mechanical stress (very commonly found throughout body)

Question 39

microtubules

Answer 39

(tubulin) maintains cell shape, coordinate complex cellular movements and transport (largest of the three structures but form small tubes)

Question 40

microtubules also form…

Answer 40

centrioles, cilia, flagella

Question 41

centrioles

Answer 41

direct DNA movement during cell division

Question 42

cilia

Answer 42

hair-like, help push substances around

Question 43

flagella

Answer 43

found in sperm cells

Question 44

tight junctions

Answer 44

prevents passage between cells, found in epithelial cells

Question 45

adhering junctions (desmosome)

Answer 45

strong connection between cells subject to high mechanical stress, lock two cells together

Question 46

gap junction

Answer 46

special junction containing connexons that serve as conduits between cytoplasm of adjoining cells allowing the passage of small molecules

Question 47

which junction allows cells to communicate and how?

Answer 47

gap junction, allows cells to communicate by allowing passage of small molecules

Question 48

what is an example of a gap junction?

Answer 48

heart muscle