Cell Bio Flashcards
(110 cards)
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