Cell Bio Flashcards
What kind of interaction is H-bond?
electrostatic interaction b/w electroneg O and electropos H –> an attraction, not a real bond –> NOT a covalent bond b/c they’re not sharing e-
Relationship b/w entropy and polar solutes vs nonpolar solutes dissolving in water
entropy = favorable and releasing energy during solvation = good vs entropy = unfavorable but energetically more favorable to associate as 1 large unit than individually solvated
What are amphipathic molec and examples?
molec w/ polar and nonpolar groups. ex: fatty acids
Hydrophobic Effect
hydrophobic substances and water will separate to minimize interactions. nonpolar hydrophobic part face inward away from water, polar hydrophilic part face outward towards water –> most energetically favorable. this is how you get protein folding, phospholipid bilayer, DNA double helix
How to find equil constant/Keq? What are the trends of Keq?
Keq = ([C]^c * [D]^d)/([A]^a * [B]^b). EXPONENTS ARE FROM COEFF
[prod]/[react]. Keq < 1 or large neg exponent –> favors reactants, Keq = 1 –> equil, Keq > 1 or large pos exponent –> favors products
How to calculate pH vs pOH?
-log[H+] = 1/log[H+] vs -log[OH-] = 1/[OH-]
pH > pKa meaning
pH < pKa –> exist in protonated form, acid > conj base
pH > pKa –> exist in deprotonated form, base > conj acid
What is a buffer? Why does H3PO4 make a good buffer?
slns that resist changes in pH as acid and base are added (try to keep pH constant); most buffers consist of weak acid & its conjugate base. b/c it has 3 H to get rid off –> their pKas = across the entire pH scale
strong vs weak acid. strong vs weak base
acids donate H+. 100% dissociates, irreversible, HA -> H+ + A- vs partially dissociates, reversible (dissociates & reassociates), HA <-> H+ + A-. base accepts H+. will combine w/ free H+, H+ + B -> BH+ vs reversible (dissociates & reassociates), B + H+ <-> BH+
How to find Ka of weak acid? What are the trends of Ka?
Ka = [H+][A-]/[HA]. Ka>1 –> favors [H+][A-] (prod), Ka<1 –> favors [HA] (react)
Know the Hendersen-Hasselbach eqn. What is this used for?
pH = pKa + log[A-]/[HA]; pKa = CONSTANT. buffer slns
Half-equivalence point
midpoint of buffering region in which half of titrant has been de/protonated thus [HA] = [A-]; pH = pKa
acidemia vs alkalemia. what’s body’s physiological pH?
blood pH < 7.35 vs blood pH > 7.35. 7.35-7.45
bicarbonate buffer system
CO2(g) <-> CO2(d) + H20 via carbonic anhydrase <-> H2CO3 <-> H+ + HCO3-
1st and 3rd steps = spontaneous. pKa carbonic acid = 6 –> pH > pKa –> likely to stay as H+ + HCO3-
hyperventilation vs hypoventilation (bicarbonate buffer system)
if you’re hyperventilating –> expelling too much CO2 –> system moves left –> blood [H+] drops –> pH dec => respiratory alkalosis vs if you’re hypoventilating –> not expelling CO2 –> system moves right –> blood [H+] inc –> pH dec –> respiratory acidosis
malnutrition and examples
too much or too little nutrition. ex: stunting, wasting, obesity
each nutrient has its own set of?
DRI: Dietary Reference Intake. 4 categories: estimated avg requirements, recommended dietary allowance, adequate intake, tolerable upper limits
importance of nutrient balance (7)
mind & spirit, immune & inflamm balance, GI balance, structural balance, hormonal & neurotransmitter balance, energy production/oxidative stress, detox & biotransformation
biochem principles in nutrition
water = medium, macronutrients = substrate (ex: carb, fat, protein), micronutrients = catalysts (ex: vitamins and minerals)
glycogen vs liver glycogen vs muscle glycogen
mainly located in liver and muscle (glu residues joined together to make polysaccharides) vs maintains blood glu levels b/w meals, stores energy during the day, can break down into glu anytime vs supplies energy for contraction during exer, only break down into glu during exer
fat vs carbs vs protein
located in adipose tissue (triglyceride - glycerol backbone + 3 fatty acids (fatty acids can be sat, monounsat, or polyunsat)), efficient fuel storage (9 kcal/g), more [H] & yield more energy when [O], aids in absorption of fat-soluble vit and carotenoid vs CHO, 4 kcal/g, glycogen in liver and muscle vs made of 9 essential aa and 11 nonessential aa, 4 kcal/g, not a primary fuel source, excess protein –> stored as fat; free aa pool = used in 3 ways: make new proteins, precursors for synthesis of nitrogen-containing cmpds (RNA, DNA, Heme), can be [O] for energy
how to distinguish scientific evidence from marketing strategies
ask 7 questions: how does study fit into entire body of evidence on topic? is the story reporting results of one story? how large is the study? was study done on animals or humans? did study look at real dz endpoints like heart dz or osteoporosis? how was diet assessed? what type of study was it? (best if it was randomized clinical trials of dietary interventions on hard endpoints)
What does Nutrient Recommendations and Dietary Guidelines 2015-2020 focus on?
healthy eating patterns, NOT individual nutrients or food in isolation; intended for ages 2+; dec sodium, added sugar, alc, sat fat and trans fat; inc fruits/veggies, whole grains, lean protein, fat-free low-fat dairy, fiber, potassium, calcium & vit D
how to eval nutrition status: ABCDE
Anthropometric (ht, wt, circumference, body composition), Biochemical (blood, urine, hair), Clinical (hair loss, thirst, skin pinch, discoloration), Diet (compare/contrast, self report but beware of bias), Economics/Emotions/Education
Know structures of D-glucose and D-fructose
Know em by heart. Glucose has 4 chiral centers, fructose has 3 chiral centers
What are anomers? How to find anomeric C?
alpha vs beta sugars (not D/L). Carbonyl C = anomeric C; If hydroxyl of anomeric C = down => alpha, if hydroxyl of anomeric C = up => beta
Pyranose vs furanose
6 ring (5 carbon + O) sugar, formed from aldoses vs 5 ring (4 carbon + O) sugar, formed from ketoses
What’s the difference b/w alpha vs beta glycosidic bonds? What type of rxn occurs to make a glycosidic bond?
both groups = same side vs both groups = opposite sides (A down, B up); dehydration
Which C’s in glucose bond to go from linear to ring? Why?
C5 (nuc) attacks w/ carbonyl C (electrophile) –> Carbonyl O bonds w/ H => OH group: if down => alpha, if up => beta
C5 is better because it’s thermodynamically stable. Using C4 hydroxyl would result in 5 members ring (not 6) —> less stable
glycosidic bonds vs N-glycosidic bonds vs O-glycosidic bonds
-OH group of anomeric C of monosacch reacts w/ -OH or -NH group of another cmpd vs found in nucleosides/tides vs join sugars to e/o or join sugar to -OH group of aa
examples of substituted sugars. know how to identify them
phosphate groups, amino groups, sulfate groups, N-acetyl groups, dietary disaccharides (sucrose (gluc-α-1,2-fru), lactose (gal-β-1,4-glu), maltose (glu-α-1,4-glu), and isomaltose (glu-α-1,6-glu)
what are glycosaminoglycan (GAG) molec? know how to recognize them
major constituent of proteoglycans, glycolipids, glycoproteins (they’re in extracellular matrix as shock absorbers), very charged –> inc polarity and formal neg charges –> hydrated. ex: heparin, chondroitin 4/6 sulfate, hyaluronate, dermatan sulfate, keratan sulfate
lipid/fat function (besides the ones mentioned in nutrition)
maintain body temp/insulation/heat generation by mito and electrical insulator like myelin sheath
know structure of fatty acids. know sat vs unsat and which config dominates in unsat
straight aliphatic chains w/ methyl on one end (where omega C is) and carboxyl group at other end. single C-C bonds vs double C-C bonds. cis dominates
examples of sat vs unsat fatty acids
behenic acid, arachidic acid, lauric acid, lignoceric acid, stearic acid, myristic acid, palmitic acid vs alpha linolenic acid, gamma, linolenic acid, palmitoleic acid, linolenic acid, oleic acid, arachidonic acid, nervonic acid
acylglycerols vs triacylglycerol (TAG) vs phosphoacylglycerols
glycerol backbone w/ 1+ fatty acid, fatty acid storage vs fatty acid storage, super hydrophobic, dietary fat = largely triglyceride, in liver/gut/adipose vs glycerol w/ fatty acids at C1 and C2 and phosphate at C3 (alone or w/ constituent; if phosphate alone => phophatidic acid), a type of phospholipid
sphingosine vs ceramide vs cerebroside vs ganglioside vs sphingomyelin
NO glycerol backbone –> sphingosine background (palmitate + serine; palmitate w/ amino and alc group) vs sphingosine structure but amino group is amide (thank to a fatty acid binding w/ amino group) vs 1 sugar bound to alc group vs mult sugars bound to alc group vs phosphate + N group bound to alc group
know how to identify cholesterol and their derivativess
cholesterol stabilizes cellular membranes: primarily the plasma membrane; precursors for bile salts and steroid hormones
know how to identify 5 nitrogenous bases and which ones are purines vs pyrimidines vs pyridines. nucleoside vs nucleotide
purines, double ring: A & G; pyrimidines, single ring: C, U, T; pyridines: vit B6. N-containing ring structures = reactive b/c they form H bonds
nitrogenous base, sugar (JOINED BY N-GLYCOSIDIC BOND); ex: adenosine vs nitrogenous base, sugar, 1-3 phosphate(s); ex: adenosine triphosphate
know names and abbrev for aa. know each category for aa. aa = major source of what?
aa = major source of nitrogen to synthesize all nitrogen-containing cmpds
the charge of aa at pH = 7.4
carboxyl group = deprotonated, amino group = protonated –> net zero charge w/ 1 neg and 1 pos charge => zwitterion
Average pKas for carboxyl vs amino groups
2 vs 9-10
List essential aa. What does it mean to be essential?
Very Heavy MILK is essential? - WTF –> V, H, M, I, L, K, W, T, F. we can’t synthesize it –> external diet
what kind of bond is peptide bond?
covalent amide bond; forming peptide bond = NOT SPONTANEOUS –> need enzyme to catalyze; resistant to denaturing; partial 2x bond character –> rigid and planar; uncharged but polar (ie. can do H bonds)
EAA deficiencies vs general protein deficiencies
lys = growth/development, EAA = strong antioxidants, low energy/alertness = phe -> tyr -> neurotransmitter, inc anxiety/stress = trp -> neurotransmitter vs sluggish metabolism, trouble building muscle mass, low energy and fatigue, poor concentration, muscle/bone/joint pain
impt biomolec derived from aa
nitrogenous bases (gly and asp), creatine (arg and gly), glutathione (cys and glu), neurotransmitters and catecholamines (tyr), ornithine and citrulline (from arg), taurine, selenocysteine (modified ser)
do you need enzyme to [H] or [O] cysteine?
yes you need enzyme to make that disulfide covalent bond
know the 7 ionizable side chains
asp, glu (lower pKa) | his, cys, tyr, | lys, arg (higher pKa)
what are the 4 weak forces? how do they relate to biomolec recognition and interaction?
van der Waals (weak inter-atomic attractions, depends on distance, can be electrostatic), ionic bonds (attraction b/w oppositely charged polar groups like cations and anions, salt bridge), H bonds (electrostatic dipolar interactions b/w delta pos and delta neg), hydrophobic interactions (tendency for polar molec to exclude nonpolar molec, entropy driven process, not electrostatic). ALL THESE WEAK FORCES DETERMINE PROTEIN FOLDING, MAINLY H BONDS
like dissolves like, polar seeks polar, hydrophobic seeks hydrophobic, lock and key example; weak forces restrict organisms to narrow range of environ conditions: temp, pH, ionic strength, solvent medium
Name and describe proteins’ 4 levels of structure
Primary: aa seq (determined by DNA seq) stabilized by covalent peptide bonds; secondary: a helix or beta sheets stabilized by noncovalent interactions (ie. H bonds, ionic bonds, vdw interactions, hydrophobic interactions) B/W THE BACKBONE (ie. R GROUPS HAVE NOTHING TO DO WITH SECONDARY STRUCTURE); tertiary: 3D structure to show hydrophobicity/phillicity; nonrandom, ordered pathway facilitated by molec chaperone; final folded structure; quaternary: multiple subunits that can function independently or cooperatively
3 classifications of proteins
globular - look like irreg balls, soluble in aq medium, fibrous - look like linear fibers, have a repeating unit structure, transmembrane - proteins that have 1+ regions aligned to cross lipid membrane
Parallel vs antiparallel beta sheets
sheets running in same direction vs alternating directions; H bonds = perpendicular to polypeptide backbone; -R groups alternate b/w above and below plane for both
super secondary structure vs domain vs motif
individual helices & sheets come together to form larger structures on the way towards tert structure vs part of the whole but doesn’t carry function by itself (analogy: head of body, arm of body) vs super secondary and domain structure rpted in related proteins that have similar function
Which type of bonds help determine tert and quat structure?
H bonds, vdw interactions, hydrophobic interactions, ionic bonds, and disulfide bonds for tert structure; disulfide bonds create loops (ex: curly hair) AND ARE THE ONLY COVALENT BONDS
At which structure does denaturation occur?
Tert —> protein loses its function. High conc of salts and detergents can denature, heat can denature. Sometimes it can affect sec and quat structures but NEVER primary —> can’t break peptide bonds
Know that proteins go thru post-translational mods
enzyme-catalyzed rxns that add a chemical group, oxidize, or modify aa: glycosylations, fatty acylation/prenylation, reg modifications, [O] aa
Hemeproteins
proteins that contain heme (a tightly bound prosthetic group composed of protoporphyrin IX & Fe2+); heme reversibly binds to O2 in myo/hemoglobin
structure and function of myo vs hemoglobin
in heart and skel muscle, O2 reservoir w/in muscle cells, complex made of 8 alpha helices, nonpolar = interior by hydrophobic interactions and polar = on surface by H bonds w/ H2O, heme sits in b/w nonpolar groups (proximal his binds to Fe2+ of heme and distal his stabilizes the 1 O2 bound to Fe2+) vs in RBCs, transport O2 from lungs to capillaries in tissue and return CO2 and H+ from tissues to lungs, quat structure: 2 alpha helices & 2 beta sheets by noncovalent interactions
Examples of allosteric effectors. what happens if high pH in lungs and low pH in tissues?
pO2, pH of environ, pCO2 (high pCO2 –> release O2), 2,3-BPG (dec O2 affinity of hgb by binding ONLY to deoxy hgb –> can’t take O2). binding of O2 to monomeric myo = not influnced by allosteric effectors. load O2 in lungs and unload O2 in tissues
Myoglobin vs hemoglobin. Know the O2 binding curves
Stores oxygen, like enzyme saturation curve (hyperbolic) –> high affinity for O2 at low partial pressure [O2} than hgb; not affected by inhibitors/modulators vs transports oxygen, sigmoidal, tense state - deoxy form of hgb, rigid, hard to bind O2 & relaxed state - easy to bind to O2 —> pos cooperativity; pO2 = x axis, sat O2 = y axis
Know high affinity vs low affinity on graph. What happens when you dec pH?
towards left top vs towards right bottom. Lower pH –> more p+ –> more oxygen released –> lower affinity for oxygen
Competitive vs uncompetitive vs noncomp vs mixed inhibitors. Know what they look like graphically (ie. LINEWEAVER BURK PLOTS AND MM PLOTS)
competes w/ S, inc Km, (inc S does overcome inhibitor) vs binds to allosteric site of ES, dec Vmax and Km (inc S doesn’t overcome inhibitor) vs either binds to allosteric site of E or ES, dec Vmax, (inc S doesn’t overcome inhibitor) vs either binds to allosteric site of E or ES, inc/dec Km and dec Vmax
Know the enzyme saturation graph. Know what comp and noncomp inhibition looks like on nml graph
x axis = [S], y axis = rxn rate
Noncomp is lower but same shape, comp has LESS steeper slope but same Vmax
Lyases vs ligases vs hydrolases vs transferases vs isomerases vs phosphorylase vs kinase vs oxidoreductase vs dehydratase vs protease
cleave w/o water or e- transfer vs linking molec together w/ water removed => condensation/dehydration vs cleaves w/ water (ex: phophatase - removes phosphate group w/ water) vs transfers functional group from one molec to another vs inter conversion of isomers (ex: D to L) vs add inorganic phosphate to another molec vs transfers phosphate group typically from ATP to another molec, also a transferase v add/remove 1 or more e- to/from substrate (ex: dehydrogenase) vs removes water vs breaks peptide bond (dehydration rxn)
What is irreversible inhibition? examples? vs non-covalent irreversible inhibitors? example?
When inhibitor covalently bonds w/ aa in active site —> destroys active site an enzyme permanently lost function —> need newly made enzymes to do the job; called mechanism-based inhibitor b/c they depen on nml rxn cycle for action, also can be called “suicide inhibitors” b/c enzyme does catalysis that leads to its own destruction. Acetylcholine (Ach) = neurotransmitter for synaptic transmission that’s degraded by acetylcholinesterase to terminate transmission signal; organophosphate inhibitors (nerve gas, pesticides) bind covalently to acetylcholinesterase –> destroyed. cyclooxygenase = enzyme produces prostaglandin H for pain response; ASA acetylates active site ser in cyclooxygenase –> prevents formation of prostaglandin H –> no pain (side note: acetaminophen and ibuprofen have similar structures to ASA but no acetyl group => reversible competitive inhibitors) vs inhibitors closely resembles TS –> inhibitor bind w/ such affinity that it will never dissoc from enzyme –> enzyme permanently inhibited. HIV inhibitor drugs have structure resembling TS of HIV protease = asp protease –> don’t dissoc –> no HIV proteins
What are allosteric enzymes? Allosteric activator vs allosteric inhibitor?
Enzymes with active site + multiple allosteric sites. Causes shift in more available active site vs causes shift in less available active site; both of these = allosteric regulation
As hemoglobin unloads oxygen, what happens to affinity of remaining oxygen?
Lowers affinity
Enzymes stabilizes transition state —> lowers activation energy —> faster rxn rate. Once in transition state, rxn can go where?
Enzymes can affect kinetics (rate of chemical rxn) BUT NOT THERMODYNAMICS (ie. They don’t affect deltaG); A single enzyme doesn’t catalyze a variety of rxns cuz they’re usually highly specific. rxn can return to substrate or move forward to products –> more likely to go prod if more energetically favorable
T/F: most enzyme-catalyzed rxns = fully reversible
T
binding energy vs proximity vs induced fit vs orientation
binding of S to E’s active site provides binding energy –> S = closer to TS –> lowers Ea –> inc rxn rate vs binding substrates inc conc w/in active site –> inc rxn rate vs binding of S induce changes in tert structure of E => conformational change –> distort S to TS vs geometry of S binding active site allows reacting molec to be in perfect orientation for rx –> inc rxn rate
serine protease vs chymotrypsin vs trypsin vs elastase
hydrolyze specific peptide bonds in proteins, mainly for digestion: made in pancreas as pro-enzymes or zymogens => inactive (they get activated when released from pancreas) vs hydrophobic binding pocket that favors aromatic residues and large nonpolar residues, Ser-OH = proximity w/ target peptide bond –> his activates ser to make nuc attack on peptide carbonyl bond –> TS –> target peptide bond cleaved but part of S = still stuck to E –> hydrolysis: E reacts w/ water (nuc) –> water attacks carbonyl C –> TS –> 2nd peptide fragment of S = released and ser = free vs deep binding pocket w/ neg charged residue (glu) at bottom that favor binding of lys and arg vs small binding pocket that favor binding of ala or gly residues
Know the Michaelis Menton eqn and plot!!!
eqn: know it by heart and how to determine v after changing variables. plot: [S] = x-axis, rxn vel = y-axis, Km = [S] at half Vmax
why regulate enzymes? how?
inc/dec enzyme activity to change rate of prod formation. alter [E] or alter E activity by non/covalent modulations
noncovalent reversible binding: pos vs neg modulator
allosteric modulators change affinity of E for S but doesn’t change Vmax. inc affinity of E for S –> inc rxn rate at given [S], “allosteric activator” vs dec affinity of E for S –> dec rxn rate at given [S], “allosteric inhibitor”
covalent reversible binding: kinase vs phosphatase
add phosphate from ATP to -OH group of S (ser, thr, tyr); phosphorylating can in/activate E (ex: glycogen phosphorylase: inactive when dephosphorylated –> when phosphorylated –> active and inc glu/dec glycogen, glycogen synthase: inactive when phosphorylated –> when dephosphorylated –> active and inc glycogen/dec glu vs removes phosphate from S by hydrolysis
glycogen phosphorylase
example of allosteric modulation and reversible covalent modification; breaks gly to make G1P for glycolysis; has T and R forms; activated by AMP binding (pos allosteric noncovalent modulator) and phosphorylation (allosterically activates the E)
regulation by protein-protein interaction and examples
proteins interact w/ weak interactions –> stimulate conformational change –> stimulate functional change. protein kinase A, calmodulin, G proteins
covalent irreversible modification and examples
some E/proteins = made in precursor inactive forms –> proteases remove parts of precursor –> protein refolds –> E/proteins = activated (ex: proinsulin becoming insulin, chymotrypsinogen becoming chymotrypsin, Achase + organophosphate, cyclooxygenase + ASA
regulation using isozymes and example
E have isoforms that catalyze same rxn –> diff regulation of enzyme in diff tissue. lactate dehydrogenase catalyzes reversible conversion of lactate to pyruvate (depends on tissue location and amount of lactate)
minerals
solid, essential, inorg nutrients
Ca2+
bones/teeth; 1000-1200mg/d; dairy, clams, oyster, legumes; fat malabsorption, rickets in children and osteoporosis in adults, tetany, colon ca, TIIDM, obese; hypercalcemia, calc kidney stones, heart arrhythmias
Na+
extracellular cation, maintain blood vol, bp, membrane potential; 1500mg/d Na, 3800mg/d salt; muscle weakness, cramps, HA, N/V; high bp and risk for CVD
phosphorous
bound to O2 in all bio systems, bone mineralization, energy transfer and storage, nucleic acid formation, acid/base balance; 700mg/d; meat, poultry, fish, eggs, legumes, nuts, cereal. renal dz, alc, diabetic ketoacidosis, resp alkalosis, starving/anorexic pts w/ refeeding syndrome; rare but renal and heart dz
K+
intracellular cation, maintain membrane potential, smooth/skel/heart muscle contraction, pyruvate kinase, nutrient of public health concern; 2600mg/d F or 3400mg/d M; potatoes, tomatoes, leafy greens, beans and lentils, prune, avocado, banana; hypokalemia; hyperkalemia –> MI
Cl
extracellular anion; salt, eggs, meat, seafood; electrolyte, gastric HCl acid, exchange anion; infants - loss of appetite, failure to thrive, weakness
Mg2+
intracellular cation; structural cofactor, allosteric activator of enzyme activity, energy prod, structural component, cell signaling and migration, ion transport; 400mg/d M, 310mg/d F; nuts, legumes, whole grains, leafy greens; hypocalcemia, hypokalemia, N/V, sodium retention, GI d/o, renal d/o, endo/metabolic d/o; diarrhea, hypotension, lethargy, confusion, abnl cardiac rhythm
Iron (Fe)
18mg/d F, 8mg/d M; heme from animal prod, non-heme from plants; iron-def anemia (fatigue, inc HR/palpitations); iron toxicity = largest cause of death in children under 6yo, GI irritation, N/V/D, constipation
Zn
divalent ion (Zn2+), cofactor for collagenase and spermatogenesis; red meat, seafood, whole grains, leafy greens and roots; delayed wound healing, suppressed immune system, hypogonadism, dec in adult hair, loss of taste and smell, alc cirrhosis
Cu
cofactor for cuproenzymes, energy prod, iron metabolism, connective tissue formation, CNS, melanin formation, antioxidant; organ meats, shellfish, nuts, whole grains, legumes; microcytic anemia, skel abnmlities, Menke’s syndrome (x-linked; Cu malabsorption –> inc urinary Cu loss and abnl intercellular Cu transport, dec lysyl oxidase, brittle kinky hair, growth retardation, hypotonia); Wilson’s dz (chronic liver dz, basal ganglia degeneration, Kayser-Fleischer ring around cornea, do veggie diet)
Selenium (Se)
based off soil content; cofactor for glutathione peroxidase –> converts peroxide to H2O; weakness an muscle pain, loss pigmentation of hair/skin/nails, dilated cardiomyopathy; selenosis - N/V, hair/nail brittleness, paresthesia
Iodine (I)
found as I-, thyroid, iodized salt; makes thyroid hormones; cretinism (poor development in children), goiter (overdevelopment of thyroid gland in adults)
bioavailability and absorption
20% of Fe = absorbed from red meat, 5-10% = absorbed from plants; 50% of Ca = absorbed from food; absorption requires transport proteins in sm intestine cell membrane (ex: Fe2+ uses transport protein DCT or DMT1 –> transports Zn, Ca, Mn, Cu, Ni, Pb)
B1
thiamin; meat, legumes, grains, black bean, soy; defic: dry beriberi - chronic low thiamin intake --> muscle wasting and weakness, peripheral neuropathy, or wet beriberi - cardiovasc/myocardial issue --> cardiomegaly, rapid HR, R heart failure, peripheral edema, or Wernicke's Encephalopathy - related to alcism --> liver dmg, ophthalmoplegia, nystagmus, ataxia, loss of recent memory, confusion thiamine pyrophosphate (TPP); used for energy transformation/metabolism (pyr dehydrog complex, alpha ketoglutarate complex)
B2
riboflavin (nonpolar); dairy, legumes, meat, spinach/broccoli (***destroyed by sunlight = why milk isn’t sold in glass bottles anymore); defic: ariboflavinosis - cheilosis, corneal vascularizataion, peripheral neuropathy
e- transport to mito to drive ATP production (FAD/FMN –> FADH2/FMNH2)
B3
niacin; meat, fish, legumes, peanut butter; defic: pellagra (rough skin), 4 Ds - dementia, diarrhea, dermatitis, death; tox: facial flushing/vasodilation –> take ASA, hyperglycemia, hyperuricemia
nicotinic acid and nicotinamide; for redox rxns: NAD+/NADH for catabolic rxns, NADP+/NADPH for anabolic rxns
B5
pantothenic acid; plants and animals; defic: burning feet syndrome - paresthesia in toes & feet/burning in feet
forms part of coenzyme A, acyl carrier group –> acyl group attaches to sulfur
B6
pyridoxine; meat, whole grains, nuts, veggies; defic: seborrheic rash (face/neck/shoulders), weakness/fatigue, cheilosis, glossitis, angular stomatitis, confusion, peripheral neuropathy, sz & convulsions; tox: sensory & peripheral neuropathy, hyperhomocysteinemia?; use to tx: carpal tunnel, morning sickness, depression pyridoxal phosphate (PLP coenzyme form), aa metabolism, ald group = functional center
B7
biotin; colonic synthesis, meat, soybean, egg yolk, cereal; defic: aloepecia, enteritis, dermatitis
cofactor for carboxylation rxn (pyr –> oxaloacetate, acetyl CoA –> malonyl CoA in FA synthesis)
B9
folate (not folic acid => synthetic); green veggies, legumes, grains, peanuts, fruit, mushrooms; defic: megaloblastic macrocytic anemia –> few large immature blood cells, fatigue, weakness, HA, irritability
tetrahydrofolate; neuro fxn, neuro development in fetus, donates methyl group in methionine synthesis, nucleic acid synthesis
B12
cobalamin; animal prod –> sorry vegan/etarians, digestion requires intrinsic factor like HCl; defic: 2. Megaloblastic Macrocytic Anemia, neuro d/o methylcobalamin - transfer methyl groups, methionine synthesis; cyanocobalamin - common dietary form
vit C
fruits and veggies, organ meats; defic: scurvy (Moeller-Barlow); tox: GI upset and diarrhea
ascorbic acid; made by animals from glu and gal, and plants; redox rxns
vit A
retinoids: retinol, retinal, retinoic acid, retinyl ester, carotenoids: beta carotene (vit A precursor); liver, fish, dairy, carrots, sweet potato, butternut squash, cantaloupe (think yellow, orange, red food)
11-cis-retinal, vision
vit D
saltwater fish, liver, beef, veal, egg yolk, dairy; defic: rickets, osteomalacia, osteoporosis; tox: bone demineralization, hypercalcemia, kidney stones
made from UVB and chol; 7-dehydrocholeterol –> cholecalciferol (D3) in animals, ergosterol –> ergocalciferol (D2) in plants and fungi
vit E
plant oil, seed, nuts, peanut butter, dark leafy greens; defic: takes 5-10yrs, fat malabsorption in premature infants; least toxic vit –> can consume 100x recommended amount
antiO2, tocopherol, tocotrienol
vit K
leafy greens, dairy, meat, eggs, fruit, cereal; defic: breast milk = very low, hemorrhage; tox: jaundice in infants
phylloquinone, menaquinone, “clotting” vit
water-soluble vit vs fat-soluble vit
not readily stored except B12, no known toxicity vs stored in adipose –> potential for toxicity, fat absorption d/o –> fat soluble vit malnutrition
cofactor vs metabolite vs cosubstrate vs prosthetic group vs vit
non-protein molec or ion require for proper functioning of enzyme vs molec produced by metabolic pathways and used by other enzymes to carry out rxns vs coenzyme bind to enzyme, carry out rxn, then dissoc from enzyme vs coenzyme bind tightly to enzyme residue at active site vs vs org, essential micronutrient
lipoamide
not a B vit, it’s a prosthetic group and works w/ other vit B cofactors; formed for lipoic acid; attaches to lys of enzyme; acyl group carrier, has redox properties: ring form w/ S-S => [O] –> NAD+ -> NADH or ring form w/ -SH groups => [H]
do MM enzymes have cooperativity? can MM enzyme be allosteric enzyme?
nope, only allosteric enzymes have cooperativity. nope
protease specificity = determined by?
substrate binding pocket on the protease
