Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry and molecular science > Module 4 > Flashcards

Module 4 Flashcards

Lipids and membrance

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are lipids?

A

Compounds that are low solubility in water. (generally non-polar

Energy storage, structural components in biological membranes, signals and cofactors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the glycerol of the fatty acids

A

O at the end of the M shaped carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the storage lipids

A

Fatty acids, triacylglycerol, waxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the membrane lipids

A

phospholipids, glycolipids, cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the signaling and cofactor lipids

A

Phospholipid derivatives, steroid hormanes, eicosanoids, lipid soluble vitamins(Vit A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the properties of carboxylic acids

fatty acids

A

almost have an even number of carbon bonds, most natural fatty acids are unbranched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are saturated fatty acids

A

no double bonds between carbons in the chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are monounsaturated fatty acids

A

one double bond between carbons in the alkyl chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are polyunsaturated fatty acids

A

more than one double bond in the alkyl chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What properties as carbon skeleton increase

A

Melting point increase, solubility decrease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Properties of a saturated fatty acid

A

Usually a fully extended conformation, almost a crystalline array stabilized by extensive hydrophobic interactions of the hydrocarbon chain. Longer chain need more energy to disrupt packing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Properties of unsaturated fatty acids

A

Usually cis configuration, usually not conjugated, pack less orderly due to the disorder. Takes lesser energy to disrupt chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are trans fatty acids used for

A

Formed by dehydrogenation of unsaturated fatty acid, increase shelf life or stability at high temperature of oil.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does trans double bond do?

A

allow fatty acid to adopt extended conformation, packed more regularly and show higher melting points than cis forms. rise of cardiovascular disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are omega-3 acids

A

essential nutrients
ALA, DHA and EPA
3rd carbon from the end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are omega-6 fatty acids

A

6th carbon from the end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are simple triacylglyceral?

A

3 fatty acids are identical

e.g. tristearin, triolein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are mixed triacylglycerols fatty acids

A

fatty acids differs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Properties of triacylglycerols

A

-hydrophobic
-provide stored energy and insulation
Adventages
-Higher energy yield than oxidation of other fuel sources such as starch or glycogen
-Not hydrated (lighter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How well does lipids store energy

A

reduce compounds: lots of available energy through oxidation

-hydrophobic nature : good packing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does lipid insulate from environment

A

Low thermal conductivity
high heat capacity
mechanical protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Are lipids water repellant

A

yes, hydrophobic nature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the compounds that are in the outer biological membrane

A

Glycolipid, oligosaccharide chans of glycoprotein, GPI-anchored protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What compounds are in the inner biological membrane

A

Sterol, integral protein(through the inner and outer), peripheral protein(both inner and outer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are phospholipids

A

Phosphate group within their polar head group
2 classes of it
Glycerophospholipids (glycerol molecule)
sphingolipids (based on sphingosine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the structure of Glycerophospholipids

A

glycerol connected to 2 fatty acid and phophate with a alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the structure of sphingolipids

A

a L shaped sphingosine connected to a fatty acid and a phosphate with choline group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the structure of choline

A

N connected with 4 carbons and connects to one carbon then the O of the phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the fatty acids connected by in the lipids

A

ester linkages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the range of charges for Glycerophospholipids

A

-4 - 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are Glycerophospholipids important for

A

structural and signalling lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the roles of sphingolipids

A

Distinctive structural and signalling roles

do not always contain phosphate group but can also fall into a glycolipid grouping

33
Q

What are the roles of glycolipids

A

Contribute to sites of biological recognition (blood type)

34
Q

What are glycolipids

A

Contains mono or oligosaccharide units in their head group

35
Q

what are oligosaccharide?

A

polymer containing sugars(carbohydrate)

36
Q

What are sterols

A

4 fused carbon rings (A, B & C =6 carbon rings, D= 5 carbon ring near fatty acid chain) with a polar head

Amphipathic

37
Q

What is the main sterol in animal tissues

A

Cholesterol

38
Q

What role does sterol play in the membranes

A

Structural roles, acting as a precursor for steroid hormones

39
Q

What experiment are done to show that the biological membranes are lipid bilayer

A

electron microscopy of cell membranes

40
Q

What is the fluid mosaic model

A

Protein embedded in the bilayer sheet by hydrophobic interactions. interaction are noncovalent(allowing fluid, dynamic properties), charges of the lipid head group contribute significantly to surface properties of membranes

41
Q

What determines the packing arrangements

A

Shape(cross section of head group relative to side chain)

42
Q

How fatty acids form micelles

A

Wedge shaped lipid unit

43
Q

What form bilayers

A

phospholipid (creat cylindrical shape)

44
Q

How are vesicle form

A

folding back on itself

45
Q

What happens to membrane as temperature increases?

A

Phase transition temperature, becomes fluid when temperature increase. biological membranes are fluid at 37 degrees

46
Q

What are the movement of lipids in membrane

A

uncatalyzed lateral diffusion(lateral movement and rapid), uncatalyzed transverse diffusion(flipflop slow)
The two monolayer can have different composition

47
Q

Properties of lateral diffusion

A

Stay within the plane of the leaflet and exchange places with neighbours

Can be measured by Fluorescence recovery after photobleaching(FRAP)

48
Q

How does TRANSBILAYER MOVEMENT work?

A

Specialised protein needed(catalysis)
Flippases (from outside)
Floppase (from inside)
Scramblase (either direction, towards equilibrium)

49
Q

How are biological membrane distributed

A

Asymmetry of distribution, therefore flip-flop(movement between layer) not favoured

50
Q

What can sterols do in the membrane

A

Prevent phospholipid packing, its concentration modulate membrane fluidity

51
Q

What is membrane raft(lipid raft or microdomains) made of

A

Sterols and sphingolipids

52
Q

What are the properties of membrane rafts

A

Slightly thicker, more ordered(less fluid) and harder to dissolve in non-ionic detergent.

Possible for lateral diffusion
Many lipid modified protein

53
Q

What roles do membrane proteins play?

A
  1. Permit selective entry and exit of molecules from cell eg. via transporters
  2. Provide recognition signals e.g. receptors for growth factors
  3. Provide structural support to the cell
54
Q

How do proteins interact with the membrane?

A
  1. Integral membrane protein 2. Peripheral protein

Most membrane proteins are free to diffuse laterally in lipid matrix

55
Q

What are Integral membrane proteins

A

Inbetween membrane

56
Q

what are Peripheral membrane proteins

A

Associated with outside surfaces

57
Q

How can we distinguish between the types of membrane proteins?

A
  1. the chemical nature of the interaction between protein and membrane
  2. the position of the protein relative to the face of the membrane
58
Q

How does peripheral membrane proteins associate with membranes

A

ionic interactions and H-bonding with:
• polar head groups of lipids
• integral membrane proteins

59
Q

How does Integral membrane proteins interact with membranes

A

hydrophobic interactions with:

• acyl chains of membrane lipids

60
Q

Properties of Peripheral Membrane Proteins

A
  1. high salt
  2. change pH
  3. chelating agent
    Released from membrane by reagents that disrupt ionic interactions
61
Q

Properties of Intergral membrane proteins

A

Released from membrane by reagents that disrupt hydrophobic interactions eg detergents (SDS)

62
Q

How does detergent work in membrane protein?

A

Dissolves membrane and maintain extracted protein in solution by interacting with hydrophobic regions of protein

63
Q

Does all membrane proteins have a unique orientation in the membrane

A

Yes

64
Q

How can we determine orientation/ arrangement of membrane proteins?

A

Protease sensitivity of proteins from intact cells

trypsin cleaves carbonyl side of lysine and arginine

Only has access to outer layer.
analyse remaining protein

65
Q

Based on sequence can we predict transmembrane protein domains?

A

Yes by Genome sequencing projecting

66
Q

How do we know which transmembrane protein domain?

A

– sequence will consist of hydrophobic amino acids
– conformation will be an α-helix
– span (segment of protein) equal to width of membrane

67
Q

What is the thickness of membrane and number of residues in alpha helix in membrane

A

3nm

20 hydrophobic residues

68
Q

How to determine the number of protein and which is in the membrane

A

using hydropathy index

69
Q

Which substance are permeable to membrane?

A

Only a few eg O2, CO2, mostly impermeable

70
Q

What are responsible for transferring small water soluble molecules across lipid by layer

A

Transport proteins

71
Q

What are the classes of membrane transport proteins

A

Carriers(transporter) and channels

72
Q

How does passive carrier protein transport

A

undergo conformational change

73
Q

Examples of Passive transporter

A

GLUT 1( glucose down a concentration gradient, no other substance)

74
Q

What is the mechanism of glucose transport

A

two conformation, Binding of glucose (from blood plasma) may induce a conformation change from T1 to T2

75
Q

Mechanism of active transporters

A

Requires energy

76
Q

Example of active transporter

A

P-type ATPases

77
Q

What is P-type ATPases

A

membrane proteins that uses ATP hydrolysis to pump ions across membranes

78
Q

What doe p-type ATPases pump

A
  • Na+-K+ ATPase (pumps Na+ out, ↑K+ in cell)
  • H+-K+ ATPase (pumps H+ out, K+ in; acidifies stomach)
  • Ca2+ ATPase (pumps Ca2+ out of cytosol)
79
Q

What maintain cell volume and create transmembrane electrical potential

A

Na and K gradient in animal cells

Biochemistry and molecular science (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions