Biochem - Block 2- Part 2

davidwurbel7's version from 2015-04-19 06:21

Uncouplers and Inhibitors of ETC

Question Answer
Decreased oxygen consumption; Increased intracellular NADH/NAD and FADH2/FAD ratio; Decreased ATP synthesis.Inhibitors of ETC
Increased oxygen consumption; Decreased intracellular NADH/NAD and FADH2/FAD ratio; Decreased ATP synthesis.Decouplers of ETC
RotenoneInhibitor, Complex I, ETC
Antimycin AInhibitor, Complex III, ETC
CyanideInhibitor, Complex IV, ETC
Carbon MonoxideInhibitor, Complex IV, ETC
AzideInhibitor, Complex IV, ETC
Hydrogen sulfideInhibitor, Complex IV, ETC
OligomycinInhibitor, ATP synthase, ETC
ThermogeninUncoupler, Proton carrier, ETC
2, 4-DinitrophenolUncoupler, Proton carrier, ETC
Thyriod hormoneUncoupler, Proton carrier, ETC
AspirinUncoupler, Proton carrier, ETC

Proteoglycans and Glycosaminoglycans

Question Answer
All amino sugars found in glycoproteins are derivatives ofGlucosamine-6-Phosphate
The precursors for the addition of four of the seven sugars that are usually found in glycoproteins – glucose, galactose, N-acetylglucosamine, and N-acetylgalactosamineUDP-Sugars
The precursors for the addition of mannose and L-fucoseGDP-Sugars
The precursor of NANA (N-acetylneuraminic acid, also called as sialic acid)CMP-NANA
Synthesized by sequential addition of nucleotide sugars on the protein (Serine, Threonine, or Tyrosine) by specific glycosyltransferasesO-linked Glycosaminoglycans
Glycosidic bond forms between xylose and Serine or GalNAc and Serine (only found in keratan sulfate II)O-linked Glycosaminoglycans
Involves dolichol phosphate in transferring branched sugar chains to the amide nitrogen of Asparagine residuesN-linked Glycosaminoglycans
The key lipid that acts as an acceptor for other sugars in the assembly of Dol-P-P-oligosaccharideDolichol-P-P-GlcNAc (Dol-P-P-GlcNAc)
Enzymes destined to lysosomes are targeted to lysosomes by a specific chemical markerMannose-6-Phosphate
Patients with I-cell disease are severely deficient in the activity ofGlcNAc phosphotransferase (N-acetylglucosamine phosphotransferase)
The receptor for this marker is located in the trans-Golgi for targeting an enzyme to the lysosomeMannose-6-Phosphate

Blood Groups

Question Answer
GlacNAc attached to Galactose attached to FucoseH Substance
GlacNAc attached to Galactose of the H SubstanceType A
N-acetylgalactosamine transferase attaches GlacNAc to Galactose of the H SubstanceType A
Galactose attached to Galactose of the H SubstanceType B
Galactose transferase attaches to Galactose of the H SubstanceType B
GlacNAc attached to Galactose of the one H Substance and Galactose attached to Galactose of another H SubstanceType AB
Active N-acetylgalactosamine transferase and Galactose transferaseType AB
Neither GlacNAc or Galactose attached to Galactose of the H SubstanceType O
Defective N-acetylgalactosamine transferase and Galactose transferaseType O


Question Answer
Fatty acids that cannot be synthesized by the human body are the ω-6 and ω -3 fatty acidsEssential Fatty Acids
Part of the ω-6 family, an essential FA that can be used to make arachidonic acid which is an important precursor for prostaglandins, throbaxanes, and leukotriensLinoleic Acid
Part of the ω-3 family, used to make eicosapentenoic acid which is a precursor for many eicosanoidsLinolenic Acid
The replacement of omega-6 family arachidonic acid with _________ in platelet membranes decreases synthesis of thrombaxene which is know to induce platelet aggregation, hence decreased risk of atherogenesis and coronary artery clot formationOmega-3 Fatty Acids
These fatty acids decrease membrane fluidity and increase the risk of atherosclerosisTrans-Fatty Acids
Glycerophospholipid with a phospholipid backbone and cholinePhosphatidylcholine (Lecithin)
Most abundant in cell membrane. Storage form of choline in the body. Choline is involved in neurotransmission and methylation reactionPhosphatidylcholine (Lecithin)
Found in the alveoli in the lungs and acts as surfactant in alveoli of lungs and maintains surface tension and prevents alveolar collapseDipamitoyl Lecithin

Metabolism of Lipids

Question Answer
Digestion of lipids begins in the _______, catalyzed by lingual lipase and gastric lipaseStomach
Lingual lipase and gastric lipase are acid stable with an optimum pH range of4 to 6
Lingual lipase and gastric lipase primarily targetShort or Medium Chain Fatty Acids
Pancreatic lipase will targetShort or Medium or Long Chain Fatty Acids
Stimulates the release of pancreatic juices from the pancreas, contraction of the gallbladder and reduces the contraction of the stomachCholecystokinin
Stimulates the release of bicarbonate mostly from the pancreas and some from the liverSecretin
Coating of dietary lipids with bile acids and salts to increase the surface areaEmulsification
Bile acids and salt inhibit the action of _____Pancreatic Lipase
Enzyme that interacts with bile acids and salt to inhibit the inhibitory effect of bile acids and salts on pancreatic lipaseColipase
Emulsified fat globule containing undigested fatty acids, cholesterol, and vitamins A, D, E and KMicelle
Emulsified fat globule containing digested fatty acids, cholesterol, and vitamins A, D, E and KMixed Micelle
The length fatty acids are not converted to their CoA derivatives and are not reesterified to 2-monoacylglycerol. Instead they are released into the portal circulation, where they are carried by serum albumin to the liverShort and Medium Chain Fatty Acids
The protein onto which fatty acids and fat soluble vitamins are loaded ontoApoliporotein B-48 (APO B-48)
Apoliprotein B-48 combined with phospholipids, triacylglycerol, cholesteryl ester and fat-soluble vitaminsChyomicron
Presence of excess fat in feces. Stools having oily appearance, difficult to flush and foul smellingSteatorrhoea

Drugs and Poisons

Question Answer
Completes with inorganic phosphate as a substrate for Glyceraldehyde 3-phosphate dehydrogenaseArsenic
Poisioning converts Glyceraldhyde-3-phosphate to 1,3 Bisphosphoglycerate skipping Glyceraldehyde 3-phosphate dehydrogenase and resulting in a loss of the production of NADH + H+Arsenic
Inhibits all the enzymes requiring lipoic acid as a coenzymeArsenite
Forms a stable complex with thiol (-SH) groups of lipoic acid, making lipoate compound unavailable as coenzyme. Arsenite
Inhibits aconitase by converting to fluoroacetyl CoA, which condenses with oxaloacetate to form fluorocitrate – a potent inhibitor of aconitaseFluoroacetate (rat poison)
Alpha-Ketoglutarate Dehydrogenase Complex is inhibited by Arsenate
Pi-H+ symporter of the ETC which transports H+ and Pi across IMM is inhibited by Arsenate
Adenine nucleotide translocase (ANT) transports ADP and ATP across IMM is inhibited byAtractyloside
Inhibits acetaldehyde dehydrogenase producing adverse effects upon the consumption of alcoholDisulfiram
Inhibits gastric and pancreatic lipaseOrlistat
Absorption of cholesterol can be further reduced by the use ofEzetimibe

Fatty Acid Biosynthesis

Question Answer
Dietary carbohydrates and proteins in excess of body’s needs can be converted to fatty acids which are stored asTriacylglycerol
Process that occurs mainly in the liver, lactating mammary glands and, to a lesser extent, in adipose tissueFatty Acid Synthesis
Citrate which moves out of mitochondria byCitrate Transporter.
Enzyme that releases acetyl CoA into the cytoplasmCitrate Lyase
Malate is converted to pyruvate using NADP+ as a coenzyme to produce NADPH plus H+Malic Enzyme
The rate limiting enzyme of fatty acid synthesis isAcetly CoA Carboxylase
The third carbon of Malonyl CoA comes fromCarbon Dioxide
Allosterically activates Acetyl CoA CarboxylaseCitrate
Alloaterically inhibits Acetyl CoA CarboxylasePalmitoyl CoA
Under the influence of glucagon and epinephrine, via protein kinase A, phosphorylate and inactivates acetyl CoA carboxylaseAMP