Lipids and membrane structures Flashcards Preview

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Flashcards in Lipids and membrane structures Deck (32)
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1

Definition of lipids

Insoluble in water, soluble in fat/organic solvents. Energy state, precursors for vitamins, steroid hormones, bile acids and phsopholipids

2

Definition of fully saturated

No C=C in FA

3

Definition of unsaturated

1 C=C in FA

4

Definition of polyunsaturated

Many C=C in FA

5

Definition of phospholipases

Important class of enzymes that bind to membrane and selectively hydrolyses components of phospholipids

6

Structure of a triglyceride

Ester of 3 FA/glycerol

7

How to form and hydrolyses triglyceride

Dehydration/synthesis
Hydrolysis

8

Structure of a fatty acid

Long chain aliphatic carboxylic acids
Metabolised via B-oxidation pathway => ATP generation

9

Naming unsaturated triglycerides

(18:1 ∆9)
No of C in chain
No of C=C
Position of C=C in relation to COOH

10

Describe the fluid mosaic model of membrane structure
Thickness of membrane

Islands of proteins in a sea of lipid
4-5nm

11

Structure of a phospholipid

PO3 2- and serine/choline/ethanolamine/inositol
Glycerol
2 FA

12

Structure of a glycolipid

Carbohydrate
Glycerol
2 FA

13

Properties of phospholipid

Bilayer in aqueous environment
Polar head group (PO3 2- serine, choline, ethanolamine, inositol)
2FA side chains
Ester bond to glycerol, hydrophobic
Amphipathic

14

Structure of sphingomyelin

Choline
Phosphate
Ceramide Sphingomyelin
Fatty acyl chain

15

Features of the lipid bilayer

Asymmetrical
Very fluid, ease which lipid molecules move about, don't move from 1 plane to another

16

Regulation of fluidity

Lipid composition of membrane defines fluidity
Increased SCFA, decreased VDW, increased fluidity
Increased UFA, decreased VDW, increased fluidity
Increased cholesterol, decreased random movements of polar heads, decreased fluidity

17

Structure of a lipid raft

Specialized membrane micro domain
More ordered, less fluid, section of limited movement
Increased cholesterol and sphingomyelin
Allows close interaction between receptors and signaling molecules

18

Types of membrane protein

Structural
Receptors
Ion channels
Transporters
Enzymes

19

Function of structural proteins

Cell-cell contact, attachment of cytoskeleton

20

Function of receptor proteins

Signal recognition and transmission

21

Function of ion channel proteins

Maintenance of ionic gradients and transmissions

22

Function of tranporter proteins

Import and export of substrates

23

Function of enzymes

Catalysis

24

Organization of membrane proteins

Integral/intrinsic proteins
Anchored proteins
Peripheral/extrinsic proteins

25

Properties of integral proteins

Embedded in bilayer
Most are transmembrane, spanning domains=a helices, b sheets

26

Properties of anchored proteins

Anchored to membrane by covalent bonds with FA

27

Properties of peripheral proteins

Attach to membrane surface by ionic interaction with integral proteins or with polar head groups of phospholipids

28

Types of phospholipases

Phospholipase A1 (Ester between FA and G)
Phospholipase A2 (Ester between FA and G)
Phospholipase C (Ester between G and PO3 2-)
Phospholipase D (Ester between PO3 2- and polar head)

29

High salt/urea treatment on peripheral, anchored and integral proteins

Removed
Remain
Remain

30

Detergent treatment on peripheral, anchored and integral proteins

Removed
Removed
Removed