Cell structure and function

Question 1

what does the phrase morphology mean?

Answer 1

the outward appearance of cells

Question 2

is a virus a living thing?

Answer 2

no

Question 3

what is an example of a procaryotic cell?

Answer 3

cocci or bacilli

Question 4

what are the main characteristics of prokaryotic cells?

Answer 4

they lack a nucleus or membrane bound organelles

Question 5

what are the main characteristics of eukaryotic cells?

Answer 5

contains a nucleus enclosed in an envelope

has membrane bound organelles

Question 6

how many layers does the nuclear envelope have?

Answer 6

2

Question 7

how much space can the vacuole in a plant cell take up?

Answer 7

90%

Question 8

what does a vacuole do for a plant cell?

Answer 8

gives it strength and rigidity

Question 9

what do nucleus’ have that allow substances to enter/exit?

Answer 9

they have pores

Question 10

what are ribosomes made up of?

Answer 10

1:2 protein: rRNA

Question 11

what do the 2 sub-units of ribosomes do?

Answer 11

the smaller reads the mRNA

the larger produces the amino acid chain

Question 12

where are ribosomes in prokaryotic cells?

Answer 12

they are free flowing

Question 13

where are ribosomes in eukaryotic cells?

Answer 13

bound to the endoplasmic reiticulum (and some ff)

Question 14

where do proteins end up after ribosomes?

Answer 14

the rough ER- very close to the nucleus, then the smooth ER,

Then they are transported, by vesicles to other areas of the cell

Question 15

where do most proteins travel to first after the smooth ER?

Answer 15

the Golgi body

Question 16

what is the Golgi body made of?

Answer 16

large, flat stacks known as cisternae

Question 17

which area of the Golgi body do proteins arrive at?

Answer 17

the cis face

Question 18

which area of the Golgi body do proteins leave from?

Answer 18

the trans-side

Question 19

what happens at the Golgi body?

Answer 19

post-translational modifications of proteins by enzymes

Question 20

what is protein thoughting?

Answer 20

where modified proteins are sorted and then transported to the correct area of the cell

Question 21

what is constitutive secretion?

Answer 21

it is the pathway for proteins to be added to the cell membrane for growth and/or repair

Question 22

what is regulated secretion?

Answer 22

the secretion of proteins at specific times e.g. a trigger signal, hormone etc

Question 23

what is lysosomal secretion?

Answer 23

when vesicles containing lysosomes can digest/destroy misfolded proteins and remove them from the cell.

Question 24

can lysosomes be sent outwith the cell?

Answer 24

yes - to destroy something outside

Question 25

what are the different skeletal fibres within the cell?

Answer 25

microtubules intermediate filaments microfilaments

Question 26

what are microtubules?

Answer 26

the largest skeletal fibre, essential to cell division e.g. tubulin

Question 27

what are intermediate filaments?

Answer 27

a skeletal fibre that is adaptable and specific to different cell function

Question 28

what are microfilaments?

Answer 28

the smallest skeletal fibre used for changing the shape of the cell e.g. actin

Question 29

which cells have the contain the most actin?

Answer 29

muscle cells

Question 30

where does movement occur with microtubules?

Answer 30

on the outside of the tubes

Question 31

where is tubulin within the cell?

Answer 31

intracellular - works between organelles and vesicles

Question 32

how do microtubules work?

Answer 32

motor molecules work to move the vesicles along the outside of the microtubule.

Question 33

what is a kinesin?

Answer 33

a motor protein that moves vesicles the (+) way, away from the nucleus.

Question 34

what is dynein?

Answer 34

a motor protein that moves vesicles the (-) way, towards the nucleus.

Question 35

how is the microfilament actin made?

Answer 35

from monomers of globular actin (g-actin) which creates polymers of (f-actin)

Question 36

what are mitochondira?

Answer 36

folded membrane on the inside where ATP is synthesised

Question 37

what do mitochondria contain?

Answer 37

its own DNA and a double membrane

Question 38

where is mitochondrial DNA inherited from?

Answer 38

the maternal line

Question 39

how do mitochondria and chloroplasts divide?

Answer 39

binary fission

Question 40

what do chloroplasts contain?

Answer 40

a double membrane and its own DNA

Question 41

what are gap junctions?

Answer 41

a tunnel of 6 proteins used for chemical communicatin

Question 42

what are adherence junctions ?

Answer 42

physically attached junctions that provide strong communication between adjacent cells

Question 43

what are tight junctions or TJ's ?

Answer 43

they are junctions that allow water/solutes between epithilial cells.

Question 44

what do epiithelial cells do?

Answer 44

line the outer surfaces of organs and blood vessels

Question 45

what are tight epithelia?

Answer 45

tight junctions between epithelial cells e.g. in the brain

Question 46

what are leaky epithelial cells?

Answer 46

few tight junctions between epithelial cells e.g. the gut