Topic 1.3: Membrane Structure Flashcards Preview

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Flashcards in Topic 1.3: Membrane Structure Deck (21):
1

What is the structure of a phospholipid?

Consist of a polar head (hydrophilic) composed of a glycerol and a phosphate molecule

Consist of two non-polar tails (hydrophobic) composed of fatty acid (hydrocarbon) chains

2

Is the head of a phospholipid hydrophilic or hydrophobic?

hydrophilic head

3

Is the tail of a phospholipid hydrophilic or hydrophobic?

hydrophobic tail

4

Define hydrophilic

attracted to water

5

Define hydrophobic

repelled by water

6

What is the polar head of a phospholipid composed of?

composed of a glycerol and a phosphate molecule

7

What is the non-polar tail of a phospholipid composed of?

composed of fatty acid (hydrocarbon) chains

8

Define amphipathic

contain both hydrophilic (water-loving) and lipophilic (fat-loving) regions

9

How are phospholipids arranged in membranes?

Phospholipids spontaneously arrange into a bilayer

The hydrophobic tail regions face inwards and are shielded from the surrounding polar fluids, while the two hydrophilic head regions associate with the cytosolic and extracellular fluids respectively

10

How are integral proteins attached to the membrane?

Integral proteins are permanently attached to the membrane and are typically transmembrane (they span across the bilayer)

11

How are peripheral proteins attached to the membrane?

Peripheral proteins are temporarily attached by non-covalent interactions and associate with one surface of the membrane

12

What proteins are permanently attached to the membrane and are typically transmembrane (they span across the bilayer)?

integral proteins

13

What proteins are temporarily attached by non-covalent interactions and associate with one surface of the membrane?

peripheral proteins

14

What are the six functions of membrane proteins?

junctions, enzymes, transport, recognition, anchorage, and transduction

15

Define junction in terms of membrane protein function

Serve to connect and join two cells together

16

Define enzymes in terms of membrane protein function

Fixing to membranes localises metabolic pathways

17

Define transport in terms of membrane protein function

Responsible for facilitated diffusion and active transport

18

Define recognition in terms of membrane protein function

May function as markers for cellular identification

19

Define anchorage in terms of membrane protein function

Attachment points for cytoskeleton and extracellular matrix

20

Define transduction in terms of membrane protein function

Function as receptors for peptide hormones

21

What is cholesterol?

Cholesterol is a component of animal cell membranes, where it functions to maintain integrity and mechanical stability

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