Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
75 Cards in this Set
- Front
- Back
carbohydrates - DRI values
|
1. RDA = 130g/day (brains needs)
2. AMDR=45-65% (low end-AI for fiber, high end-hypertriglyceremia) 3. AI fiber = 38 g/day men, 30 g/day women 4. added sugars < 25% kcal |
|
carbohydrates - dietary guidelines
|
1. increase fruit/veg, whole grain, non-fat/low-fat dairy
2. 3 servings whole grain 3. decrease discretionary calorie intake |
|
fats - DRI values
|
1. NO RDA/AI for total fat
2. AMDR = 20-35% (low-carb intake too high; high-AI fiber, obesity) 3. AI linoleic = 17g/day men, 12 g/day women AI linolenic = 1.6g/day men, 1.1 g/day men 4. cholesterol, sat fat, and trans fat as low as possible |
|
proteins - DRI values
|
1. RDA = .8g/kg body weight (for essential AAs-based on N-balance studies)
2. AMDR = 10-35% (low-essential AA req; high- AI fiber, fat intake too low) 3. Requirements for source of essential AAs and nitrogen 4. high quality programs (all essential, right proportions, digestable) |
|
digestion - mouth
|
starch -(salivary amylase)-> maltose
|
|
digestion - stomach
|
carbs: salivary amylase inactivated (low pH)
proteins: HCl denatures proteins; pepsinogen (inact)-(HCL)->pepsin (act) proteins -(pepsin)->smaller PPs |
|
digestion - small intestine
|
carbs: starch -(pancreatic amylase)-> maltose [secreted by pancreas through duct to duodenum)
lac/mal/suc->MSs (in microvilli) fats: TGs -(pancreatic lipase)-> 2 FFAs + 1 monoglyceride **when fat enters SI, cholecystekinen secreted/triggers gallbladder to release bile (made in liver) |
|
digestion - large intestine
|
carbs: dietary fiber -(fermentation)-> SCFA, menthane, CO2, H2
|
|
carbohydrates - absorption
|
MSs absorbed from GI tract; go into blood/lymph
apical membrane: glucose/galactose-active trans (SGLT1); fructose-fac diff (GLUT5) basolateral membrane: all 3-fac diff (GLUT2) once absorbed in GI cells, go through portal vein to liver (fruc-metabolized/converted to gluc; sucr-converted to gluc) |
|
lipids - absorption
|
micelles (LCFAs>10 Cs) absorbed into intestinal mucosal cells
SCFAs directly absorbed; go through portal vein-->liver |
|
lipids - transportation
|
chylomicrons form from dietary TGs; released by exocytosis into lymph system; go through thoracic duct-->blood
VLDL - transport synthesized TGs |
|
proteins - absorption/transportation
|
end products = free AAs, DPs, TPs, oligopeptides
transportation = active transport acidic AAs, neutral AAs, phenylalanine/methionine, proline/hydroxyproline |
|
carbohydrates - 4 components
|
1. basal metabolism - energy expenditure needed to maintain bio. fxns); 30% ion trans
2. physical activity 3. heat increment - expenditure due to digestion; 5%BMR + activity 4. growth (incr body mass, preg, lactation) |
|
ATP regeneration (2 rxns)
|
1. substrate-level phosphorylation
2. oxidative phosphorylation - substrate oxidized/coenzyme reduced, then passes e's to ETS to generate ATP |
|
substrate-level phosphorylation
|
In glycolysis:
1,3-BPG+ADP-->3-PG+ATP PEP+ADP-->Pyruvate+ATP In TCA cycle: succinyl coA+ADP-->succinate+ATP |
|
oxidative phosphorylation
|
substrate oxidized
coenzyme reduced (NAD-->NADH + H) coenzyme passes e's into ETS to generate ATP ex: GAP+NAD-->1,3-BPG+NADH+H |
|
importance of glucose (4)
|
1. used by every cell
2. only E-source for RBCs 3. only anaerobic E-source 4. only E-source for brain/nervous tissue (except during starvation) |
|
requirements for glucose to enter cells (3)
|
1. facilitated diffusion - needs transporter (insulin= +muscle/adipose, -brain/liver uptake)
2. go down concentration gradient 3. activated glucose (glu-6-P) |
|
HK vs. GK
|
HK-when blood glucose LOW
location=all cells except liver Km=10^5 (higher affinity) Vmax=low inhibitors=glu-6-P GK-when blood glucose HIGH location=liver Km=10^-2 (low affinity) Vmax=high affinity no inhibitors |
|
glycolysis - overall rxn
|
glucose + 2 ATP + 2 NAD --> pyruvate(aerobic)/lactate(anaerobic) + 4 ATP + 2 NADH + H
|
|
glycolysis - energy loss rxns (2)
|
1. glucose -(HK)-> glucose-6-P
2. fructose-6-P -(PFK1)-> fructose-1,6-BP total loss=2 ATP |
|
glycolysis - energy gain rxns (2)
|
1. 1,3-BPG-(PGK)->3-PG
2. PEP-(PK)->pyruvate total gain=4 ATP |
|
regulation of glycolysis - PFK1
|
negative = ATP, citrate
positive = AMP/ATP, fructose-6-P, fructose-1,6-BP (made by PFK2, activated by F-6-P) |
|
regenerating coenzymes (3)
|
1. oxidation of GAP:
GAP+NAD-(GAP DH)-> 1,3-BPG+NADH 2. regenerating NAD+ anaerobically pyruvate+NADH-->lactate+NAD 3. regenerating NAD+ aerobically a)malate shuttle b)glycerol-3-P shuttle |
|
malate shuttle
|
in cytosol:
OAA-->Malate NADH-->NAD in mitochondria: Malate-->OAA NAD-->NADH ATP=3 |
|
glycerol-3-P shuttle
|
in cytosol:
DHAP-->glycerol-3-P NADH-->NAD in mitochondria: glycerol-3-P-->DHAP FAD-->FADH2 ATP=2 |
|
4 pathways of pyruvate
|
1. alanine
2. lactate (anaerobic glycolysis) 3. acetyl coA 4. oxaloacetate (gluconeogenesis) |
|
oxidative decarboxylation of pyruvate - rxn
|
pyruvate + CoA-SH--(PDH complex)-->acetyl coA + CO2
|
|
oxidative decarboxylation of pyruvate - enzymes
|
1. TPP (vitamin=thiamin) - allows for decarboxylation of pyruvate
2. CoA (vitamin=pantothenic acid) - picks up 2C unit from lipoic acid 3. FAD (vitamin=riboflavin) - accepts e-s from lipoic acid 4. NAD (niacin) - accepts e-s from FADH2 and donates to ETS |
|
oxidative decarboxylation of pyruvate - steps
|
1. TPP binds to pyruvate, allowing it to be decarboxylated
2. acetyl group transferred to lipoamide-->acetyllipoamide 3. CoA picks up acetyl group from acetyl lipoamide (acetyl coA) 4. e-s from lipoic acid transferred to FAD (-->FADH2) 5. e-s from FADH2 transferred to NAD (-->NADH) 6. NADH transfers e-s to ETS |
|
oxidative decarboxylation of pyruvate - regulation
|
kinase (-):
pos-acetyl coA/NADH neg-NAD phosphatase (+) pos-insulin neg-acetyl coA/NADH |
|
TCA cycle - energetics
|
1 substrate level phosphorylation (succinyl coA+GDP-->succinate+GTP)
3 NADH+H 1 FADH2 total ATP=12 |
|
TCA cycle - overall reaction
|
GDP + acetyl coA + coNZ --> GTP + 2 CO2 + coNZ-H
|
|
TCA cycle - important reactions (2)
|
1. OAA+acetyl coA--(citrate synthase)-->citrate
neg-lack of OAA 2. isocitrate+NAD --(ICDH)-->alpha-KG+NADH+H neg-NADH |
|
TCA cycle and ETS
|
important=maintaining energy balance in cell
key reg enzyme (TCA cycle)= ICDH build up of NADH---->glucose cant get into cell |
|
lipoprotein lipase - fxn/location
|
fxn- liberates TGs from lipoproteins
location-walls of blood capillaries |
|
lipoprotein lipase - Km/effectors
|
Km:
heart/breast(lactation)= low Km for LPL adipose= high Km for LPL effectors: glucose/insulin: + on adipose LPL - on heart/skeletal LPL glucagon: - on adipose LPL + on heart/skeletal LPL |
|
lipids as energy source
|
heart and liver - almost always use FAs for E
muscle - uses FAs when it can brain cant use FAs for E |
|
sources of FAs for energy (2)
|
1. dietary- FAs picked up by chylomicrons and used for E
2. adipose tissue (energy low)- TGs--(HSL)-->glycerol + FFAs pos-glucagon/epinephrine neg-insulin **FFAs released and travel into blood bound to albumin |
|
beta oxidation - overall reaction
|
palmitate+2ATP+8CoA+7NAD+7FAD ----> 8 acetyl coA+2ADP+7FADH2+7NADH+H
|
|
beta oxidation - energetics/regulation
|
energetics:
7 NADH, 7FADH2, 2 used=33 ATP regulation: 1. availability of O 2. availability of FAs (diet/adipose) 3. oxidized cofactors (NAD/FAD) |
|
beta oxidation - sparing glucose
|
1. produces NADH + H (inhibits ICDH, builds up citrate, spills out....glucose cant go into cell)
2. produces acetyl coA (inhibits pyruvate DH, aCoA-nongluconeogenic) |
|
ketone bodies - types
|
made in liver
types: 1.beta-OH butyrate (urine) 2. acetoacetate (urine) 3. acetate (in breath) |
|
ketone bodies - conditions
|
1. HSL activated (+glucagon/epinephrine)
2. beta oxidation activated (FAs/oxygen available, oxidized coenzymes) 3. body unable to get into TCA cycle (no OAA for acetyl coA to react w/) |
|
glycogen synthesis - reactions (3)
|
mainly muscle/liver
1. glucose--(HK)-->glu-6-P 2. glu-6-P--->UDP-glucose 3.**UDP-glucose+glycogen(n)--(glycogen synthase)-->glycogen (n+1) |
|
glycogen synthesis - regulation
|
1. covalent modification
kinase (-) phosphatase (+) 2. hormonal glucagon (-) insulin (+) 3. allosteric glucose-6-P (+) glycogen (-) |
|
glycogen degredation - overall rxn/regulation
|
glycogen(n)--(glycogen phosphorylase)-->glycogen(n-1)+glucose-1-P
1. covalent modification kinase (+) phosphatase (-) 2. hormonal glucagon (+) insulin (-) 3. allosteric ADP/ATP (+) glucose-6-P (-) |
|
TG synthesis - location/requirements
|
location=liver (packaged/sent out in bood) and adipose (stored as TGs)
requirements: 1. glycerol-3-P a)glycerol--(glycerol kinase)-->glycerol-3-P [not in adipose] b)DHAP-->glycerol-3-P 2. FAs (FA synthesis rxn) |
|
fatty acid synthesis - overall reaction
|
acetyl CoA + 7 malonyl CoA + 14 NADPH + H --(FA synthase)--> Palmitate + 8 CoA + 7 CO2 + 6 H20 + 14 NADP
*insulin increases amts of FA synthase |
|
fatty acid synthesis - source of acetyl CoA
|
1. formation of citrate (mitochondria)
2. formation of acetyl coA (cytosol) citrate --(citrate lyase)--> acetyl coA + OAA pos-citrate |
|
fatty acid synthesis - source of malonyl coA
|
in cytosol:
acetyl coA+CO2 --(acetyl coA carboxylase)--> malonyl coA pos-citrate(potent)/ insulin neg-LCFacyl CoA, glucagon/epinephrine |
|
fatty acid synthesis - source of NADPH
|
1/2:
malate+NADP --(malic enzyme)--> pyruvate+CO2+NADPH+H [source of malate: citrate --(citrate lyase)--> acetyl coA + OAA; OAA-->malate] 1/2: glucose-6-P DH (in HMP) |
|
fate of AAs (4)
|
1. oxidation (AA-->pyr/acetyl coA/into TCA cycle)
2. glucose synthesis 3. protein synthesis 4. other N-containing compounds |
|
urea synthesis - reaction
|
nitrogen primarily excreted as urea in urine
Aspartate+HCO3+3ATP+NH4+NH3 --->urea+fumarate+2ADP+2Pi+AMP+PPi |
|
urea synthesis - uses up...(5)
|
1. HCO3-
2. H20 3. 4 ATP 4. NH4 glutamate+NAD--(glutamate DH)-->alpha-KG+NADH+NH4 5. NH3 (aspartate) |
|
transamination - alpha keto acids and their AAs
|
1. glutamate/alpha-KG
2. aspartate/OAA 3. alanine/pyruvate |
|
transamination - GOT/GPT
|
alpha-KG+aspartate--(GOT)-->glutamate+OAA
alpha-KG+alanine--(GPT)-->glutamate+pyruvate **always start rxns with alpha-KG |
|
deamination reactions (4)
|
1. NH4 lost in urine (kidneys)
glutamine--(glutaminase)-->glutamate+NH4 2. captured in urea cycle (liver) glutamate--(glutamate DH)-->alpha-KG+NH4; NH4 to urea cycle 3. captured as glutamate (muscles) alpha-KG+NH4+NAD ---> glutamate+NADH 4. captured in glutamine (muscles) glutamate+NH4--(glutamine synthase)-->glutamine |
|
significance of transamination/deamination rxns
|
1. detoxification
dietary surplus- N eliminated via trans/deamination rxns or urea formation 2. energy production dietary surplus- C-skeletons conserved as FAs (FA synthesis-lipogenesis) fasting- AAs-->glucose (GN) |
|
gluconeogenesis - enzymes (4)
|
1. pyruvate carboxylase (bypasses PK)
2. PEPCK (bypasses PK) 3. FDP'ase (bypasses PFK-1) 4. G6P'ase (bypasses HK/GK) |
|
gluconeogenesis - controls
|
pos - citrate, insulin
neg - F-2,6-BP, F-6-P, AMP/ATP glucose (-) for G6Pase acetyl coA (+) for glutamate DH |
|
carbs as glucose precursors
|
carbs:
(in muscle) glycogen-->glu-1-P-->glu-6-P-->lactate (in liver) lactate-->pyruvate-->gluconeogenesis-->GLUCOSE |
|
proteins/lipids as glucose precursors
|
proteins-leucine/lysine only nongluconeogenic AAs
lipids: (in adipose) TGs--(HSL)-->FFAs+glycerol (in liver) glycerol--(glycerol kinase)-->glycerol-3-P glycerol-3-P--(gly-3-P DH)-->DHAP-->gluconeogenesis-->GLUCOSE |
|
glucose/alanine cycle - transamination to remove N to break down proteins
|
in muscle:
1. AA "X" + alpha-KG --> KA "X" + glutamate 2. glutamate + pyruvate --(GPT)-->alpha-KG+alanine 3. alanine-->liver in liver: 4. alanine+alpha-KG--(GPT)-->pyruvate+glutamate a)pyruvate-->gluconeogenesis-->GLUCOSE b)glutamate+NAD--(glutamate DH)-->alpha-KG+NH4+NADH+H [NH4-->to urea cycle] |
|
glucose/alanine cycle - deamination to remove N to break down proteins
|
in muscle:
1. alpha-KG+NH4+NADH+H--->glutamate+NAD 2. glutamate+NH3--(glutamine synthase)-->glutamine In kidney: 3. glutamine --(glutaminase)-->glutamate+NH4 [NH4-out in urine] |
|
glucose/alanine cycle - gluconeogenesis in liver
|
1. alanine (from muscle) enters liver
2. alanine+alpha-KG--(GPT)-->glutamate+pyruvate a)pyruvate-->gluconeogenesis-->GLUCOSE b)glutamate+NAD--(glutamate DH)-->alpha-KG+NH4+NADH glutamate+OAA--(GOT)-->alpha-KG+aspartate [aspartate gives NH3 to urea cycle] |
|
fasting - glycogen degradation in liver
|
in liver (releases free glucose into blood-G6Pase)
1. glycogen--(glycogen phosphorylase)-->glycogen(n-1)+glucose-1-P 2. glucose-1-P-->glucose-6-P 3. glucose-6-P--(G6P'ase)-->glucose+Pi [not in muscle] |
|
fasting - glycogen degradation in muscle
|
1. glycogen--(glycogen phosphorylase)-->glycogen(n-1)+glucose-1-P
2. glucose-1-P-->glucose-6-P 3. glucose-6-P-->glycolysis-->lactate 4. lactate to liver in liver: 5. lactate-->pyruvate-->OAA-->gluconeogenesis-->GLUCOSE **no G6Pase enzyme |
|
eating after fasting - where does glucose go first?
|
glucose taken to muscle first (when BG still low)
hexokinase has lower Km, meaning glucose will go to muscle cells (enters through fac. diffusion) |
|
feasting - after all cells have met energy requirements
|
glucose stored as glycogen (mostly in muscle/liver)
1. glucose-->G6P-->UDP-glucose 2. UDP-glucose+glycogen(n)--(glycogen synthase)-->glycogen (n+1) pos: posphatase, insulin, G6P neg: kinase, glucagon, glycogen |
|
feasting - after glycogen stores are filled
|
FA synthesis (high levels of glucose)
7 malonyl CoA+Acetyl CoA+14 NADPH+H --(FA synthase)--> Palmitate+8 CoA+7 CO2 + 6 H2O + 14NADP glucose goes to liver when BG is high glucose high=G6P high=inhibits HK |
|
bad idea to supplement w/ individual AAs
|
AA's share common transporters; too much of 1 AA may crowd out others that share that transporter and inhibit absorption
|
|
why body runs on gluconeogenesis when its starving (even though it costs energy)
|
RBCs can only use glucose, brain prefers glucose, and cell is operating anaerobically
|
|
2 molecules that can pick up free ammonium ion
|
1. alpha-kg+NH4-->glutamate
2. glutamate+NH4--(glutaminase)-->glutamine |
|
molecuse that CARRY nitrogen from trans/deamination rxns
|
transamination - alanine
deamination - glutamine |