Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry: Ch 8 & Ch 9 > Ch 9: Lipids & Biological Membranes > Flashcards

Ch 9: Lipids & Biological Membranes Flashcards

1
Q

lipids

A

biological molecules soluble in organic solvents

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

fatty acid

A

carboxylic acid (polar head) with long-chain hydrocarbon side groups (nonpolar tail)

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

Saturated

A
  • only single bonds
  • flexible (rotation)
  • tightly packed (large # of weak intermolecular forces—Van der Waals + hydrophobic effect)
  • melting point increases with molecular mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

no db/triple bonds in saturated fats excluding…

A

polar head

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

fats are harder to melt as you increase length of chain bc?

A

bc it is more stable

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

is it easier to make even or odd numbered fatty acids?

A

even

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

unsaturated

A
  • contain double bond
  • rigid, cis configuration
  • lose packing, reduced interactions
  • lower melting points
  • delta 9 = db bond at 9th carbon from carb. acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the more weak interactions contributing to something…

A

the stronger the overall forces of that

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

triacylglycerols

A
  • another form of lipids
  • energy reservoirs in animals
  • 2-3 diff types of fatty acids
  • yield more energy bc less oxidized than carbs
  • also provides warmth (animals)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

less oxidized…

A

… yield more energy per mass unit

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

Fats and oils

A

complex mixtures of triacylglycerols

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

triacylglycerols: 2-3 diff types of fatty acids

A

name by adding -oyl to end of each fatty acid and ending with “glycerol”

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

adipocytes

A
  • provide energy (2-3 months)
  • synthesize triacylglycerols
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

glycerol

A

attach all fatty acids to hydroxyl groups

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

trans fat consumption

A
  • db bonds in unsaturated acids oxidized to aldehydes & carboxylates
  • hydrogenated to reduce some of the db bonds
  • side effect: convert cis to trans
  • causes cardiovascular disease (increase consumption of trans fat, increase of cholesterol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

trans conformation

A
  • have issues digesting this
  • increases melting pt as u can pack molecules tightly
  • increases Van der Waal interactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

glycerophospholipids

A
  • modification of triacylglycerols
  • bind to active site, fatty acid tail hangs out
  • aka phosphoglycerides
  • amphiphilic
  • phosphatidic acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

glycerophospholipids: phosphoglycerides

A

C1 & C2 esterfied with fatty acids, C3 contains phosphate

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

glycerophospholipids: amphiphilic

A
  • nonpolar aliphatic tails & polar phosphoryl-x heads
  • x can be sugars, AAs, hydrogen, etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

glycerophospholipids: phosphatidic acid

A
  • X is H
  • saturated C16 or C18 at C1 position
  • unsaturated C16 to C20 at C2 position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

phospholipases

A
  • enzymes that hydrolyze glycerophospholipids
  • can disrupt membranes (detergents & in venoms)
  • selectively cleaves carbon 2
  • use destruction of these as a signal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

plasmalogens

A
  • special type of glycerophospholipids
  • contain ether linkage
  • “X” = Serin, ethylamine
  • easily oxidized
    react w/ free radical that are naturally produced by metabolism, to prevent damage to other molecules
    “sacrificial limbs”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

sphingolipids

A
  • membrane component
  • amino alcohol derivatives; most derived from C18 amino alcohol sphingosine
  • no ester linkages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

sphingolipids: ceramide

A

N-acyl fatty acid derivative of sphingosine

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

sphingolipids: sphingomyelins

A

bear phosphocholine or phosphoethanolamine group

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

sphingolipids: cerebrosides

A

ceramide w/ single sugar head group

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

sphingolipids: gangliosides

A

ceramides with attached oligosaccharides

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

phosphocholine & phosphoethanolamine

A

most common sphingolipids that occur in plasma membranes

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

Steroids

A
  • another form of lipids (eukaryotes), things like cholesterol + hormones
  • 4 fused, nonpolar rings
  • steroid hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

steroid hormones

A
  • glucocorticoids
  • mineralocorticoids
  • androgens & estrogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

glucocorticoids

A

affect carbohydrate, protein, and lipid metabolism

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

mineralocorticoids

A

regulate salt/water excretion

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

androgens and estrogens

A

sexual development and function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

isoprenoids

A
  • other lipids
  • build from 5C units that resemble isoprene
    —- Ubiquinone (coenzyme Q—major player in cell respiration as it acts as e carrier in mitochondria)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

fat soluble vitamins

A
  • vitamin A
  • vitamin K
  • vitamin E
  • long carbon chains = nonpolar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

vitamin A

A

(retinol)
- derived from plant products like Beta-carotene, part of vision process
- deficiency = blindness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

vitamin K

A
  • involved in blood clotting
  • excessive bleeding & easy bruising
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

vitamin E

A
  • group of compounds, prevents oxidative damage
  • big group of compounds…needs to be monitored
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Vitamin D

A
  • vitamin D1 & D2 —-inactive forms
  • active vitamin D promotes intestinal absorption of Ca2+
  • water insoluble, can accumulate in fatty tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Vitamin D2

A
  • R = Y (ergocalciferol)
40
Q

vitamin D3

A
  • R = X (cholecalciferol)
41
Q

cholesterol

A
  • most abundant protein
  • tail will change
  • OH group makes cholesterol slightly polar
  • does better in inorganic solvents
42
Q

Lipid bilayer formation

A
  • driven by hydrophobic effect
    —–size constraints
  • made up of phosphoglycerides & sphingolipids
43
Q

hydrophobic effect

A

not an attraction b/t non polars but exclusion of non-polar tails by water to maximize entropy

44
Q

liposome

A

closed, self-sealing solvent filled vesicles bounded by single bilayer

45
Q

Lipid bilayer: fluidlike properties

A
  • layers are not static (are moving)
  • transverse/flip-flopping of lipids is rare (thermodynamic barrier)
  • lateral diffusion (movement w/in the same plane)
  • constant rotation around C-C bond of lipid tails
    ——-polar heads nestle in next to each other
46
Q

transverse diffusion (flip-flop)

A
  • takes massive amnts of energy
  • won’t see polar heads flip-flop, but move up & down
47
Q

lateral diffusion

A
  • moves in same plane
  • most likely to happen
  • rapid
48
Q

lipid bilayer: fluidity temperature dependent

A
  • HIGHLY DEPENDENT
  • above transition temperature = liquid crystal
    ——-organized liquid, still have bilayer but a lot of space (movement allowed)
  • below, gel-like solid
49
Q

cholesterol decreases membrane what?

A
  • membrane fluidity
  • by getting into spaces b/t fatty acids = motion restricted
50
Q

how do animals regulate the fluidity of its cells?

A

by changing the types of lipids that are in it

51
Q

membrane proteins

A
  • integral (intrinsic) proteins
  • asymmetrically oriented amphiphiles
  • transmembrane
  • glycophorin A
52
Q

integral (intrinsic) proteins

A
  • associated tightly w membrane via hydrophobic interactions
  • anchors
53
Q

asymmetrically oriented amphiphiles

A

larger side & smaller side

54
Q

transmembrane proteins

A

spans both faces of membrane

55
Q

glycophorin A

A
  • 3 domains: inside, outside, bilayer interacting portions
  • help segregate diff parts of membrane
56
Q

How to completely disrupt membrane/extract integral proteins?

A

use a detergent

57
Q

lipid bilayer: structure

A
  • indicative of the type of protein
  • hydrophobic portions interact with lipid bilayer
  • shield polar backbone
  • alpha-helices common structure (taller than width of mem + common way we see integral proteins sit in mem)
58
Q

shield polar backbone

A
  • helices w/ nonpolar residues
  • nonpolar AAs as part that spans membrane = protection
59
Q

lipid bilayer: structure (pt 2)

A
  • hydrophobic portions interact w lipid bilayer tails
  • shield polar backbone
  • Beta-barrel possible (to form channels thru bilayer)
  • porins = channel-forming proteins
60
Q

Lipid linked proteins

A
  • lipid acts as anchor (not like integral proteins)
  • prenylated = built from isoprene (isoprene = decorate/identify proteins)
  • Cys-X-X-Y
  • linked to Cys S atom (thioether + most common way to connect to mem)
  • intercellular membranes & cytoplasmic face of plasma membrane
61
Q

Cys-X-X-Y

A
  • X = often aliphatic amino acid
  • Y = Ala, Met, Ser (farnesylated)
    OR
  • Y = Leu (geranylgeranylated)
62
Q

Lipid linked proteins: fatty acylated

A
  • 2 common ways: myristic acid & palmitic acid
63
Q

fatty acylated: myristic acid

A

(C14, saturated)
- amide linkage, thioester
- myristylation stable for life
- located cytosol, ER, inner face of plasma membrane & nucleus
- plays nice, high melt. pt., no rotational restrictions, packs tight

64
Q

fatty acylated: palmitic acid

A

(C16, saturated)
- amide linkage, thioester
- palmitoylation reversible, regulates
- located only cytoplasmic face of plasma membrane
—–where we need to regulate which proteins are sitting on membrane

65
Q

lipid linked proteins: glycophosphatidylinositol-linked (GPI-linked)

A
  • located on exterior face of plasma membrane
  • protein attaches at C terminal (n-terminus is free)
66
Q

fatty acids will vary based off?

A

protein we’re trying to attach to

67
Q

peripheral membranes

A
  • aka extrinsic
  • bind to membrane via electrostatic & hydrogen bonding
  • easiest to dissociate from mem
  • still important (cytochrome C)
68
Q

membrane structure

A

fluid mosaic model- membrane is not static, proteins can be imbedded
- constant movement

69
Q

fluid mosaic model

A
  • fluorescence recovery after photobleaching (FRAP)
70
Q

photobleaching

A

put sm energy/light into fluorescent molecule “essentially turns it off”

71
Q

defining cell shape

A
  • sub membranous (inside mem) network of proteins as membrane skeleton (proteins under mem)
  • certain things will be anchored/immobile
  • spectrin
  • ankyrin
  • gate & fences model (herding sheep)
72
Q

spectrin

A
  • protein that provides membrane skeleton of erythrocytes (dense, triple stranded alpha helical coil coils)
73
Q

ankyrin

A
  • binds integral membrane ion channel protein
  • anchor mem skeleton to membrane
74
Q

membrane lipids

A
  • asymmetrically distributed (will find one type of lipid in one leaflet vs the other more frequently)
  • carb tail interior of mem, polar head exterior membrane
  • synthesized on cytoplasmic face of mem (inner leaflet)
  • flip-flop to get to correct side
75
Q

flip-flop

A
  • conformational change, push lipid thru enzyme
  • flippase
  • phospholipid translocase
  • new membrane created from expanding existing membranes
76
Q

flippase

A
  • enzyme, catalyzes outer to inner leaflet flip of lipid
  • anchored in mem
77
Q

phospholipid translocase

A
  • transport specific phospholipids across a bilayer
  • LOW TO HIGH CON
  • “taking it up”
  • enzyme itself will move across bilayer then release it when it’s on other side
78
Q

floppase

A
  • opp fucntion of flippase
  • catalyzes inner to outer leaflet
79
Q

scramblase

A
  • do it in either direction
80
Q

lipid rafts

A
  • small, closely packed glycosphingolipids & cholesterol (lil thicker, less fluid like)
  • glycosphingolipids associate laterally via weak interactions of head group, cholesterol fills the gaps
  • expedite the process?
81
Q

secretory pathway

A
  • pathway of proteins from ribosomes thru rough ER mem. embedded into matrix
  • an assembly of complex structure made of multiple enzymes & activated by GTP in order to get protein embedded in membrane
  • harvest energy from cleavage of phos. groups from GTP to drive this process
82
Q

translocon

A
  • pore/hollow cylinder that we can send things through
  • transmembrane channel facilitates protein transport thru ER reticulum and into lipid bilayer
    —– alpha, beta, gamma subunits (10,1, and 1 TM alpha- helices respectively)
    —– small helix blocks entry acting as plug to prevent unwanted leaking of other small mol
    —— soluble proteins move enter channel
    ——- transmembrane proteins enter channel, alpha helix opens to lipid bilayer releasing into lipid bilayer
    main function = create soluble conduit for polar protein to move thru
83
Q

Intracellular vesicle transport

A
  • translation (syn of polypep. from an mRNA transcript from ribosome)
  • golgi where posttranslational modifications made
  • transportation thru golgi
    movement is progressive
84
Q

transportation thru golgi

A
  • anterograde transport
    —- move from backfold (closest to ER) to the end furthest away from ER
  • cisternal progression (maturation)
    —– when ur going thru golgi parts (change & mature into next type)
85
Q

transportation coated vesicle

A
  • membrane secretory & lysosomal proteins transported in coated vesicles
  • coated vesicle
  • doesn’t change protein environment = highly favorable
86
Q

coated vesicle

A
  • encased by proteins acting as flexible scaffolding
    —- buds of originating membrane
    —- fuses to target membrane
  • preserves orientation of transmembrane protein
    —-portions of the proteins in the vesicle that are in cytosol environment remain in cytosol
87
Q

coated vesicle: parts

A
  • clathrin
  • COPI
  • COPII
88
Q

Clathrin

A
  • forms flexible cages/protein called triskelions
    —-transport mem and secretory proteins b/t golgi and plasma mem
    —– participate in endocytosis (vacuole from mem for the purpose of taking in something)
89
Q

COPI

A
  • transports proteins b/t golgi compartment
  • never leaves golgi
90
Q

COPII

A
  • transports proteins from Er to golgi
91
Q

directing proteins

A
  • carbohydrate recognition
  • C-terminal sequences
92
Q

carbohydrate recognition

A
  • sugar code
  • trafficking of lysosomal proteins depend on oligosaccharide
93
Q

C-terminal sequences

A
  • soluble resident ER proteins have C-terminal -Lys-Asp-Glu-Leu, -Lys-Lys-X-X, or -Lys-X-Lys-X-X-X where X = any AA
  • if altered, secreted out of ER
94
Q

vesicle fusion

A
  • new membranes generated by expansion of existing membranes
    —–vesicle buds off membrane and fuses to target membrane
  • biological membranes don’t spontaneously fuse, mediated by proteins called SNARE’s
95
Q

R-SNAREs

A
  • conserved Arg, associate w/ vesicle membranes
  • single letter code
96
Q

Q-SNAREs

A
  • conserved Gln, associate w/ target membranes
  • single letter code
  • form coiled coils (a-b-c-d-e-f-g, a and b hydrophobic)
  • see pseudo repeats = holds coil shape
97
Q

membrane fusion

A
  1. zipping
  2. hemifusion
  3. two bilayers leflets farthest apart are brought together
  4. fusion pore formation
  5. fusion pore expands
98
Q

virus fusion proteins

A
  • mechanism & machinery diff from membrane fusion
  • budding from infected cell - membrane enveloped virus
    1. host cell recognition by virus
    2. activation of viral membrane fusion machinery
    3. fusion of viral membrane w host
    (genetics)
  • integral proteins that recognize specific glycoproteins are gonna act as the cell surface receptors
  • virus vesicles taken up by receptor mediated endocytosis (resembles of fusion of a vesicle w/in a mem)

Biochemistry: Ch 8 & Ch 9 (2 decks)

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