Cells and Organelles

Question 1

what is the function of a flagellum

Answer 1

help with movement

Question 2

what is a flagellum made of

Answer 2

microtubules

Question 3

list the cilia types

Answer 3

respiratory epithelial cells
brain ependymal cells
epithelial cells lining the fallopian tubes

Question 4

what are erythrocytes and what is their structure

Answer 4

red blood cells
anucleate and biconcave

Question 5

what is the role of keratinocytes and how is its structure supporting this

Answer 5

makes a lot of protein = extensive RER

Question 6

what are microtubules and what is their role

Answer 6

dynamic structures (cell movement/ intracellular transport of organelles/ mitotic spindle (mitosis))

Question 7

what are microtubules made of

Answer 7

polymers of a and b tubulin

Question 8

what stabilises microtubules

Answer 8

proteins
tau protein

Question 9

condition when cilia are defective

Answer 9

kartagener’s syndrome

Question 10

condition when microtubules are defective

Answer 10

Alzheimer’s disease

Question 11

what is the cause of Tay Sachs disease and list its symptoms/ outcomes

Answer 11

build up of gangliosides in the brain and spinal cord; caused by gene mutations; seizures/sight/hearing/unlikely to live past 5

Question 12

how are mitochondrial disorders inherited and what does it cause

Answer 12

dysfunction of the mitochondrial respiratory chain; clinically heterogenous group (down female line)
mitochondrial inheritance comes from the ovum
3 donor babies

Question 13

where are tight junctions and what is their function

Answer 13

apical
gate = regulation of paracellular permeability (ions/solutes/water)
fence = formation of apical and basolateral intramembrane diffusion barrier (makes polar)

Question 14

tight junctions (gate defective)

Answer 14

hypomagnesaemia (intestinal/ renal permeability; enteric pathogens; obesity; coeliac disease

Question 15

tight junctions (fence defective)

Answer 15

loss of polarity; less differentiated; cells can detach; progression towards cancer

Question 16

what are cellular junctions

Answer 16

transmembrane protein complexes

Question 17

list the cell-cell junctions

Answer 17

adherens (actin)
desmosomes (ifs)

Question 18

list the cell-ECM junctions

Answer 18

focal adhesions (actin)
hemidesmosomes (ifs)

Question 19

give an example of a channel forming junction

Answer 19

GAP junctions - cell-cell contact; composes of hexamers of Connexins; allow passage of small molecules

Question 20

what does defective hemidesmosomes lead to

Answer 20

epidermolysis bullosa (butterfly skin)
caused by genetic defects

Question 21

what are cytoskeletons

Answer 21

intermediate filaments - structural role/ mechanical strength

Question 22

how does a cytoskeleton function as a motor protein

Answer 22

kinesins move cargo away from the centrosome (adjacent of nucleus, centre where microtubules are anchored and initial polymerisation)
dyenins move cargo towards

Question 23

what are axonemes

Answer 23

the cytoskeletal component of cilia and flagella
allow for bending

Question 24

what are axonemes comprised of

Answer 24

microtubules and dyenin actin filaments (microfilaments)
polymerised actin
myosin (allows movement)

Question 25

how does myosin allow movement of axonemes

Answer 25

pushes out sections of the plasma membrane (lamellipodia or filophobia)
helps move along cell surface