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Flashcards in Transmembrane Transport Deck (89)
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1

What are the three major functions of cell membranes

1. separate the cell contents from the outside
2. separate the contents of different organelles from the rest of the cell
3. form a permeability barrier to many biologically important molecules

2

cells need to take up various substances such as large uncharged polar molecules including

glucose and fructose

3

cells need to take up various substances such as ions, give some examples

k+ mg2+ , basically any ion lols

4

cells need to take up various substances such as charged polar molecules including

amino acids, atp, proteins, nucleic acids

5

what is the typical composition of a cell membrane in terms of the amount of protein compared to the amount of lipid

50% protein, 50% lipid

6

the membrane of a mitochondria has 75% protein and 25% lipid, why is this

because oxidative proteins are found throughout the membrane for respiration

7

the membrane of myelin sheath is 25% protein and 75% lipid, why is this

because the nerve cells require insulation

8

what component of the cell membrane is the key to the 'selective permeability' we describe cells as having

it is the protein component of the membrane that is key to the selective permeability to most physiologically important solutes. these are the gateways into cells

9

membrane proteins have a wide variety of functions, label the following five proteins

channels, transpoters, connexins, receptors and enzymes

10

what do membrane proteins that are channels do

they allow the ions to be transported across in order to maintain equilibrium

11

give an example of protein channel

the CFTR protein channel

12

what does the CFTR protein channel transport across

chloride ions

13

what does cftr stand for

Cystic fibrosis transmembrane conductance regulator

14

what do mutations in the CFTR protein channel result in

cystic fibrosis

15

what do transporter proteins along the cell membrane do

transport substances such as amino acids, sugars and drugs up the concentration gradient

16

what do connexins do

they interact with the cytoskeleton, extracellular matrix or other cells

17

what do protein receptors along the cell membrane do

they are involved in endocytosis and or/transmission of signals across the membrane without movement of the ligand

18

give an example of a protein transporter

ABCB1

19

what does abcb1, the protein transporter do

it is a drug efflux pump, causes multidrug resistance

20

give an example of a connexin/integrin membrane protein

Cx26

21

where is Cx26 found

between cochlear cells

22

what does Cx26 allow to happen

allows ion flow and so communication between cells

23

a mutation in the gene of Cx26 results in what

congenital deafness

24

congenital means?

present from birth

25

what ion does the Cx26 connexin transport

k+ ions

26

give an example of a protein receptor

FGFR3 + FGF

27

if there is a mutation in the protein receptor FGFR3 + FGF, what disease can occur

achondroplasia

28

what is achondroplasia

a cause of dwarfism

29

give an example of an enzyme membrane protein

enzyme phospholipase c

30

phospholipase c which is an example of an enzyme protein on the cell membrane converts phosphatidylinositol into which two substances

ip3 + DAG