Anatomy of the Cell

Question 1

what is a eukaryotic cell?

Answer 1

one with a true nucleus

Question 2

what is the plasmalemma?

Answer 2

the cell membrane

Question 3

what is the role of the cell membrane?

Answer 3

separates the cytoplasm from the outside environment

Question 4

what can move through the cell membrane easily?

Answer 4

water
oxygen
small hydrophobic molecules

Question 5

what cannot move through the cell membrane?

Answer 5

charged ions

Question 6

what is an organelle?

Answer 6

a small cellular organ with a specific function that is essential to life

Question 7

what is the role of the mitochondria?

Answer 7

produces energy (ATP)

Question 8

what is the role of the rough endoplasmic reticulum?

Answer 8

protein synthesis

Question 9

what is the role of the smooth endoplasmic reticulum?

Answer 9

cholesterol + lipid synthesis

detoxification

Question 10

what is the role of the golgi apparatus?

Answer 10

modification and packaging of secretions

Question 11

what are lysosomes?

Answer 11

hydrolytic enzymes for intracellular digestion

Question 12

what is an inclusion?

Answer 12

anything else in the cell that isn’t essential to life

Question 13

what are two ways an inclusion may appear in a cell?

Answer 13

the cell might synthesise it

it could be taken up from the extracellular environment

Question 14

what are the three main classes of filaments in the cytoskeleton from smallest to largest ?

Answer 14

microfilaments
intermediate filaments
microtubules

Question 15

what are microfilaments made from and what property does this give them?

Answer 15

actin

this can assemble into filaments and then dissociate, making them very dynamic

Question 16

what are intermediate filaments made of and what does this lead to?

Answer 16

six main proteins that vary in cell types

cell types can be identified by what makes up their intermediate filaments

Question 17

what are microtubules composed of?

Answer 17

two tubulin proteins, one alpha and one beta

it is a hollow tubule

Question 18

where do microtubules originate?

Answer 18

the centrosome

Question 19

what is included in a microtubule?

Answer 19

stabilising proteins = microtubule associated proteins (MAPS)

Question 20

what filament allows proteins to move through the cell?

Answer 20

microtubules

Question 21

what three things are microtubules important in?

Answer 21

cilia
flagella
mitotic spindle

Question 22

what proteins attach to microtubules and move along them through the cell?

Answer 22

kinesin and dynein

Question 23

what type of proteins are kinesin and dynein?

Answer 23

ATPase’s

Question 24

what direction does kinesin move in?

Answer 24

towards the cell periphery

Question 25

what direction does dynein move in?

Answer 25

towards the cell centre

Question 26

how do the three filaments form the cytoskeleton?

Answer 26

they attach to each other and the cell membrane, creating a dynamic internal scaffolding in the cell

Question 27

what organelle is found in a centrosome and what are these made of?

Answer 27

centrioles made of specialised microtubule segments

Question 28

what surrounds the nucleus?

Answer 28

a double layered membrane (the nuclear envelope) this is porous

Question 29

what is found between the two layers of the nuclear envelope?

Answer 29

the perinuclear cistern

Question 30

what is found on the surface of the outer nuclear membrane?

Answer 30

ribosomes, continuous with the RER

Question 31

what RNA molecules are transcribed in the nucleus?

Answer 31

mRNA | tRNA

Question 32

what RNA molecules are transcribed in the nucleolus?

Answer 32

rRNA

Question 33

what is the nucleolus?

Answer 33

a dense area in the nucleus

Question 34

what does the nucleus contain?

Answer 34

euchromatin | heterochromatin

Question 35

what is euchromatin?

Answer 35

DNA that is more dispersed and actively undergoing transcription

Question 36

what is heterochromatin?

Answer 36

DNA that is highly condensed and not undergoing transcription

Question 37

where are ribosomes formed?

Answer 37

the nucleolus

Question 38

what is each ribosome made of and what does each part do?

Answer 38

large subunit = catalyses peptide bond formation small subunit = binds RNA

Question 39

what does the export of ribosomes from the nucleolus depend on?

Answer 39

the nuclear pore complex

Question 40

what does the endoplasmic reticulum form?

Answer 40

a network of interconnecting membrane bound compartments

Question 41

what are the two types of endoplasmic reticulum?

Answer 41

rough (RER) | smooth (SER)

Question 42

what covers the surface of the RER?

Answer 42

ribosomes

Question 43

what does the amount of RER suggest about a cell?

Answer 43

how active it is

Question 44

what type of cells have more than a normal amount of SER?

Answer 44

cells that synthesise steroid hormones

Question 45

which mitochondrial membrane folds and what does this form?

Answer 45

the inner membrane forms cristae to increase the surface area

Question 46

which tissue type contains many intercellular junctions?

Answer 46

epithelia

Question 47

what are the three types of intercellular junctions?

Answer 47

occluding anchoring communicating

Question 48

what does an occluding junction do?

Answer 48

links cells to form a barrier that prevents diffusion

Question 49

what are other names for occluding junctions?

Answer 49

tight junctions | zonula occludens

Question 50

what do anchoring junctions do?

Answer 50

link submembrane actin bundles in adjacent cells ti provide mechanical strength

Question 51

what are other names for anchoring junctions?

Answer 51

adherent junctions | zonula adherens

Question 52

what is a desmosome?

Answer 52

a type of anchoring junction that links submembrane filaments of adjacent cells

Question 53

what is another name for desmosomes and where are they common?

Answer 53

macula adherens common in the skin

Question 54

what do communicating junctions do?

Answer 54

allow movement of molecules between cells

Question 55

what are communicating junctions also called?

Answer 55

gap junctions

Question 56

where are gap junctions commonly found?

Answer 56

epithelial smooth muscle cardiac muscle