Anderson Intro 1 Flashcards
Which sugars make maltose? What is the bond?
Glucose + glucose. alpha1-4
Which sugars make lactose? What is the bond?
Galactose + glucose. beta1-4
What sugars make sucrose? What is the bond?
Glucose + fructose. alpha1-beta2
What is the only beta linkage human (babies) can break down?
Lactose - lactase specific
What sugars make up glycogen? What is the bond
Multiple glucoses. Chains are alpha1-4, and branching are alpha1-6.
Define glycogen.
Storage form of glucose in animals. Highly branched (more than amylopectin)
Define inulin
Tuber starch. Hydrolyzed fructose. Easily soluble in warm water.
Define cellulose
Plant starch/insoluble fiber. beta1-4.
Monosaccharide absorption
Glucose and Galactose - Na+ cotransporter
Fructose - facilitated diffusion
How much ATP does one sugar molecule produce?
36-38 ATP
B2 name and role in TCA
Riboflavin, FAD
B1 name and role in TCA
Thiamine, active form - thiamin diphosphate (alpha-ketoglutarate dehydrogenase)
B3 name and role in TCA
Niacin, NAD
B5 name and role in TCA
Pantothenic acid, co-enzyme A
Where in the Kreb cycle is most of the ATP created?
Oxidative phosphorylation.
In oxidative phosphorylation, which membrane (inner/outer) is most active?
Inner!
What is the rate limiting enzyme in glycolysis?
Phosphofructokinase (requires 1 ATP)
Induction (first step) enzymes for glycolysis and where they are found?
Hexokinase - all tissues, muscles
Glucokinase - liver/pancreas
Aerobic glycolysis ends in…
Pyruvate (Net 2 ATP)
Anaerobic glycolysis ends in…
Lactate (Net 2 ATP, no more produced)
What stimulates/inhibits glycolysis?
Insulin - stimulates
ATP - inhibits
What inhibits PFK?
ATP and citrate
What converts phospheno-pyruvate (PEP) to pyruvate?
Pyruvate kinase (creates 2 ATP)
What converts pyruvate to acetyl-coA?
Pyruvate dehydrogenase (final step to TCA)
Elevated lactate dehydrogenase lab values indicate what?
Anaerobic glycolysis making too much lactic acid.
What four enzymes are required for gluconeogenesis?
Mitochondria: Pyruvate carboxylase (pyruvate to oxaloacetate)
malate shuttle
Cytosol: Pyruvate carboxykinase (oxaloacetate to PEP)
F-1,6-Diphosphatase (F-1,6-P to F-6-P)
Glucose-6-phosphatase (G-6-P to Glucose)
What stimulates/inhibits gluconeogenesis?
Epinephrine, Glucagon, Cortisol - stimulates
Insulin - inhibits
What is the rate limiting step of gluconeogenesis?
Fructose-1,6-diphosphates - inhibited by F6P
What is the use of liver glycogen? What is the use of muscle glycogen?
Liver: Blood glucose maintenance, usually between meals. (12-18hr fast)
Muscle: Vigorous exercise, starvation.
What is the important enzyme that takes glucose-6-phosphate into the glycogenesis reaction?
Phosphoglucomutase (G6P to G-1,6-Bis-phosphate)
Requires Mg
What is the major controller of glycogen concentration?
Phosphorylase-a
How does cAMP (affected by insulin or glucagon) affect glycogenolysis or glycogenesis?
Increased cAMP - activates phosphorylase leading to glycogenolysis. Reduces glycogenesis.
Decreased cAMP - activates glycogen synthase leading to glycogenesis. Reduces glycogenolysis.
What is the primary function of the pentose pathway?
NO ATP CREATED, Generates NADPH (required for FA synthesis) and ribose (nucleic acid synthesis)
Where does the pentose pathway occur?
Cytosol
What are the oxidative and non-oxidative phases of phases of hexose-monophosphate shunt (pentose pathway)?
Oxidative: NON-REVERSIBLE
G6P to Ribulose-5-phosphate
Requires - G6P Dehydrogenase and 6-Phosphogluconate Dehydrogenase
Non-oxidative: REVERSIBLE
R5P back to G6P
Requires: transketolase and transaldolase
One of the most common causes of hemolytic anemia?
G6P dehydrogenase deficiency
Glutathione redox cycle require what product of the pentose pathway to be converted to the reduced form?
NADPH
Why is glutathione important to peroxide detoxification?
Required for glutathione peroxidase. Otherwise H2O2 explodes RBC - G6PD deficiency.
What substance builds up with diabetic retinopathy (product of fructose)?
D-sorbitol
What product is galactose “laundered” through to form usable glucose?
Glycogen (glycogen synthase from UDP galactose)
How is a mammary gland a “modified” sweat gland? What’s the modification?
Can produce lactose (via lactose synthase using UDP galactose and glucose)
Name omega-6, omega-3 fatty, omega-9 acids.
Omega9- oleic
Omega6- linoleic acid
Omega3- linolenic acid
What lipids are in the phospholipid/triglyceride family?
Phosphatidylcholine, triacylglycerol, cardiolipin
Important for cell membrane integrity.
Acyl vs. Acetyl
Acyl - large fat for oxidation or storage
Acetyl - 2 carbon molecule for TCA
How does insulin influence triglycerides?
Causes livers to increase TG in blood.
ApoE receptors receive which lipid?
Chylomicrons
Where does the LDL come from?
The liver!
ApoB receptors receive which lipid?
LDL
What is the difference between IDL, VLDL, and LDL?
How much interaction they have had with HDL. HDLs are very hormone-like. Trades triglycerides with cholesterol ester. Takes away the oxidizable TGs for CE in LDL. Oxidized LDL damages blood vessels.
A-1 receptors receive which lipid?
HDL, turn on cholesterol removal.
What does ACAT do? CE Hydrolase?
ACAT - Takes free cholesterol and keeps it safe as CE (Cholesterol ester) less oxidizable and also lessl usable.
CE hydrolase - takes CE to free cholesterol, makes it more usable.
What is the primary fat-soluble antioxidants?
Tocopherols = Vitamin E
How is Vitamin E absorbed and carried?
LDLs
How many carbons do eicosanoids have?
20 C - linoleic acid, arachidonic acid, alpha-linolenic acid.
What are the end cytokine products of linolenic acid, arachadonic acid, and linoleic acid?
Linolenic: prostaglandin, thromboxane, and leukotriene 3 (anti-inflammatory)
Arachadonic: “” 2 (pro-inflammatory)
Linoleic: “” 1 (anti-inflammatory)
What fat inhibits conversion of linoleic and linolenic acid to GLA and EPA respectively?
Trans-fats ( inhibits delta-6 desaturase)
What inhibits/stimulates delta-6 desaturase?
Inhibits: stress, hormones, age, cancer
Stimulates: B-6, Mg, Zn
What inhibits/stimulates delta-5 desaturase?
Inhibits: EPA, DHA, glucagon
Stimulates: Insulin
What enzyme frees membrane phospholipids to arachadonic acid? What stimulates/inhibits?
Phospholipase A2
Stimulates: angiotensin 2, bradykinin, epi, thrombin
Inhibits: corticosteroides
What converts arachadonic acids to leukotrienes, prostaglandins, thromboxanes?
Lipoxygenase and cyclooxygenase
Inhibited by NSAIDs
Define micelle.
Bile encrusted fats in the GI lumen.
What enzyme converts TG to FFA and glycerol?
Lipoprotein lipase
What are the two produces to acetoacetyl CoA?
HMG- CoA (HMG-CoA Synthase) and Acetyl-CoA (Thiolase)
HMG -CoA can go to Ketones or Cholesterol. What enzyme takes it to which product?
HMG CoA lyase - Ketone
HMG CoA reductase - Cholesterol (mevalonate)
What class of drugs blocks HMG CoA reductase?
Statins
What is the final enzyme for the conversion of demusterol to cholesterol?
delta24 reductase
What organ systems can use ketones? To which organ are ketones toxic?
Muscle and brain.
Liver.
What inhibits/stimulates conversion of TG to FFA?
Stimulates: epinephrine and cortisol
Inhibits: insulin
What molecule helps shuttle the fat into the mitochondria?
Carnitine (amino acid-like)
Where is carnitine palmitoyl transferase I? II?
I - outer membrane
II - inner membrane
What does carnitine acyl transferase?
Recycles carnitine and helps CPT II get a hold of the fat to carry it into the mitochondria.
Protein bonds: Primary, Secondary, Tertiary, Quaternary
Primary: covalent between AA, strongest bond
Secondary: first folding, disulfide bonds, weaker bonds
Tertiary: secondary folding, s-s bonds
Quaternary: multiple polypeptides, e.g. hemoglobin.
Define protein vs. peptide.
Protein = >10 AA long Peptide = 2-10 AA long
Essential amino acids…
Histidine, isoleucine, leucine, lysine, methionine, valine, phenylalanine, threonine, tryptophan, arginine
PVT TIM HALL
Non-essential amino acids…
Alanine, aspartate, glutamine, glycine, cysteine, proline, asparagine, tyrosine
What are the three amino acids that make up glutathione? Which one is the middle and rate limiting AA in glutathione synthesis?
Cysteine, glutamine, glycine
Cysteine.
Products of tyrosine?
Dopamine, norepinephrine, epi, T3, T4, melanin
Products of tryptophan?
5-HTP (Serotonin), melatonin, niacin
Product of glutamate?
GABA
Products of glycine?
Porphyrin (heme), creatine (glycine + arginine)
Product of histidine?
Histamine
What is a zymogen?
Inactive form of enzyme.
How are all proteins absorbed in the GI?
Na+ dependent transporter
What do the following enzymes do? Hydrolase Aldolase Dehydrogenase Hydratase Isomerase Esterase
Hydrolase - adds H2O to break bonds
Aldolase - cleaves C-C bonds to form aldehydes
Dehydrogenase - removes H from substrate
Hydratase - adds H2O to C-C bonds w/o breaking bond. Can also remove H2O to create double bond.
Isomerase - converts between isomers
Esterase - hydrolyzes ester linkages to form an alcohol and acid
What are the phase I and phase II liver detox mechanisms?
Phase I - CYP450 for fat-soluble compounds (steroid hormones endogenous and exogenous)
Phase II - Conjugation for water-soluble compounds (add amino acid anchor)
Adding glycine - hippurates
Glutathione - mercapturates
Glucuronic acid - glucoronides
What are two damaging bi-products of phase I detoxification?
Peroxide and superoxide
