Biochem - Lipids

Front 1

Fatty acids

Fx of gauche confirmation?
Heating promotes?
Membrane fluidity factors?
Lipid rafts contain?
Short v. med v. long-chain?
Essential FA?

Back 1

Incr gauche -> dec chain length & incr cross-sectional area

Gauche conformation -> fluid state

Dec by cholesterol
Incr by unsaturated lipids

Cholesterol, sat sphingolipids, sat phosphoacylglycerols

Short = 2-4C
Med = 6-10C
Long = 12-26C

Linolenic (omega-3)
Linoleic (omega-6)

Front 2

Lipid absorption

Primary digestion products? 3
Where from micelles? Mix with?
Which attach to alb?
How FA absorbed? 2-monoglyceride? Chol? 4

Back 2

FA, chol, 2-monoglyceride

Jejunum; bile acids

Short-med length FA

FA activated by fatty acyl coA
+ 2-mono-glyceride -> TG
Chol esterified
Packaged into chylomicrons

Front 3

Fat mobilization

Enhanced during? 2
Fx insulin/glucagon on adenylate cyclase? 2
Triacylglycerol lipase fxn? Where?
Tissues using FA? 5
Chylomicron broken down by capillaries of? 6 Via?
FFA transported by? 2

Back 3

Starvation; fasting

Glucagon promote; insulin inh

Convert TG -> glycerol + 3 FA (adipose tissue)

Heart, muscle, kidney, liver, brain (ketone bodies)

Sk muscle, adipose, liver, heart, lung, kidney
LPL

Albumin, FABP

Front 4

FA transport into mitochondria

Activated by? Into? Where?
Converted into? By? Where? Inh? Promote?
Converted into? By? Where?

Back 4

Acyl CoA synthetase
OMM
FA -> FA CoA

FA CoA -> fatty acylcarnithine
CPT I across IMM
+: Vit C; -: malonyl CoA

Acylcarnithine -> FA CoA by CPT II in IMM

Front 5

FA synthesis

Occurs in?

Acetyl coA converted to? B/c?
Malic enzyme pathway?

RLS? Via? Vit req? Def? 5

FA synthase:
Config?
Carrying/transferring req?
ACP?

# NADPH/cycle?

Released by?
Odd # formed if?

Regulation: 2
High insulin/glucagon ratio stim: 4

Back 5

Cytosol

Citrate; acetyl coA won't cross mitochondria membrane

Citrate + ATP -> OAA + ADP + Acetyl coA via citrate lyase
OAA + NADH -> malate + NAD+ via malate dehydrogenase
Malate + NADP+ -> pyr + NADPH via malic enzyme

Acetyl coA -> malonyl coA via acetyl coA carboxylase
Biotin def: dermatitis, depression, dry skin/eyes; can arise from raw egg ingestion

Head-to-tail
Phosphopentethine; cys residue
Acyl carrying protein

2 NADPH/cycle

Thioesterase release palmitate

Start w/ propionyl coA -> odd #

Glucagon -> cAMP -> PKA -> acetyl coA carboxylase-P (inactive)
Insulin -> protein phosphatase -> acetyl coA carboxylase (active)

malic enzyme, citrate lyase, FA synthase, G6PD

Front 6

Beta oxidation:

Step 1? 3
Step 2? 1
Step 3? 2
Step 4? 3

If even # C? If odd?

FADH2 energetics? NADH?Acetyl CoA?
ATP req for activation?

Peroxisome work on? Mitochondria?

Back 6

Acyl CoA dehydrogenase
Uses FAD
Inh by Jaimaica vomitting sickness

Enoyl CoA hydratase

β-hydroxy acyl CoA dehydrogenase
Uses NAD+

β-keto thiolase
Uses CoA-SH
Generate aceyl CoA + FA CoA

Continues w/ even
Odd end in propionyl coA -> -> succinyl CoA

2 ATP/cycle; 3 ATP/cycle; 12 ATP;
2 ATP for FA activation

P: Long-med FA
M: Med FA

Front 7

Ketone body synthesis

Ketone bodies: 3
Occur in?
Catalyzed by? Located in?
Regulation in starvation state?

Back 7

Acetate, ACAC, BOHB

Mitochondrial matrix

HMG CoA reductase; liver

Acetyl coA low -> can't react w/ OAA so converted to KB

Front 8

Liproteins: fxn/route, apolipoproteins:

Chylomicrons 3, 4
VLDL 2, 3
IDL 2, 2
LDL 3, 1
HDL 3

Back 8

Deliver TG to peripheral tissue
Deliver chol to liver as chylomicron remnants
Secreted by intestinal epithelial cells
B-48, A-IV, C-II, E

Deliver hepatic TG to peripheral tissue
Secreted by liver
B-100, C-II, E

Formed by VLDL degradation.
Deliver TG & chol to liver
B-100, E

Deliver liver's chol to peripheral tissue
Formed from VLDL in peripheral tissue
Taken up by liver cell via R-mediated endocytosis
B-100

Mediate reverse chol transport to liver
Repository for ApoC, apoE for chylomicron, VLDL
Secreted from both liver, SI

Front 9

Lipoprotein enzymes:

LPL: synth? translocated to? bound to? fxn? 2 Regulated by? 3 Found in? 3
LCAT: fxn? 2
ACAT: fxn? 2

Back 9

Synth in parenchymal cells
Translocated to intestinal surface; bound to heparin sulfate
Process chylomicron, VLDL for TG -> FA hydrolysis
Postprandial: Incr insulin -> Inc LPL activity in adipose
Postabsorption: Dec activity in adipose, Incr activity in muscle
Sk muscle3, heart, adipose

Storage & transport of chol esters in lipoprotein core
Cleaves FA -> attach to chol -> more hydrophobic -> penetrate HDL core

Preps chol for stoarge
Intracellular esterification of chol when taken up from LDL

Front 10

Familial dyslipidemia: Name? Incr?

I: Serum? 2 Patho? 2 Sx? 3
IIa: Serum? 1 Patho? 2 Class? 5 Sx? 3
IV: Serum? 1 Patho? 1 Sx? 1

Back 10

Hyperchylomicronemia
chylomicrons
TG, chol
LPL def or altered C-II
Pancreatitis, HSM, eruptive xanthomas

Familial hypercholesterolemia
LDL
Chol
Auto dom; absent/dec LDL-R
1: promoter
2: Golgi to cell surface
3: Cys disulfide mutation
4: Clustering in pits
5: LDL-R recycling impaired
Accelerated atherosclerosis, tendon xanthomas, corneal arcus

Hypertriglyceridemia
VLDL
TG
Liver overproduction of VLDL
Pancreatitis

Front 11

Abetalipoproteinemia

Genetics?
Def? 2
Sx? 5
Bx? 1

Back 11

Auto R
Apo B-100, Apo B-48
Failure to thrive, steatorrhea, acanthocytosis, ataxia, night blindness
Chylomicron accumulation in enterocytes b/c can't be exported

Front 12

Chol biosynth

7 steps?
Regulation? 3

Back 12

1. 2 Acetyl coA -> acetoacetyl coA
2. Acetoacetyl coA + acetyl coA -> HMG CoA
3. HMG CoA + NADPH -> NADP+ + melavonate via reductase (RLS)
4. Melavonate -> activated 5C isoprene using ATP
5. 6 isoprenes -> 30C squalene
6. Squalene cyclize -> 4 ring lanosterol w/ C3 oxidation
7. 3C cut -> cholesterol

Sterol inactivate SCAP (regulatory protein for regulatory element)
Sterol promoted HMG proteolysis
Glucagon -> cAMP -> PKA -> HMG CoA reductase-P (inactive)

Front 13

Bile acid synth/conj

Where synth? Stored? Released by?
RLS of synth?
Chenocholic v. cholic acid
Conj w/? 2 Why?
Bile salt pK v. intestinal lumen pH
2o bile salts made by? Purpose?

Back 13

Liver; gallbladder
Released by CCK -> contraction GB

α-hydroxyl added to C7 of B ring via 7α-hydroxylase

Cheno: 3α, 7α diol
Cholic: 3α, 7α, 12α triol

Conj w/ glycine or taurine
Lower bile salt pK -> more ionized -> better detergents

Bile salt pK = intestinal lumen = ~ 6 -> abt 1/2 ionized

Bacteria remove glycine & OH @ C7 -> less soluble -> more excreted

Front 14

Sitosterolemia

Incr in? 2
Patho? 2
Sx? 2
Tx? 2

Back 14

Chol, plant sterols

Mutation ABCG5/8 -> pump chol & plant sterols into lumen

Xanthomas, Incr plant sterols

Diet low in plant fats, nuts, chocolate, seeds; bile acid resins

Front 15

PG, TX, LT

Derived from? COX v. LOX?
Subscript indicates?
PGD2 located in? 3 PGE2? 1 PGF2? 1 PGI2? 1 PGH2 =?
Fx of: PGI2/E2/D2? 3 PGF2? 2

TX contain? Located in? Fx: TXA2? 3

LT lack?
LOX enzymes where?
LTB4 fx? 6
LTCDE fx? 4 Strength?
Aspirin fx?

Back 15

C20 poly-unsaturated FA (AA)
Cyclooxygenase -> PG, TX
Lipoxygenase -> LT

# double bonds

Brain, spinal cord, mast cells
Kidney
Uterus
Vasc endothelial cells
PGH2 = precursor for other PGs
PGI/E/D2: vasodilatin, dec plt aggregation, T cell prolif
PGF2: vasoconstriction, bronchoconstriction

O incorporated to form 6 member ring
TXA2 in plt
Vasoconstriction, plt aggregation, bronchoconstriction

No internal ring
5-LOX PMN; 12-LOX plt; 15-LOX eosinophilic
Incr vasc perm, T cell prolif, chemotaxis, IFN-g, IL-1, IL-2
D > C > E: Incr bronchoconstriction, vasc perm, GI contraction, IFN-g

COX-inh -> No PG, No TX, but LT still