Term
|
Definition
phenylalanine, tryptophan, tyrosine
absorb UV light
more asymmetry in ring = stronger absorption |
|
|
Term
| polar uncharged side groups |
|
Definition
serine, threonine
hydrophilic = H bonds
on surface of proteins
-OH can be phosphorylated |
|
|
Term
|
Definition
has thiol group
can form disulfide bridges with each other via oxidation
can be acylated to form thirster by proteases |
|
|
Term
| basic, positively charged side groups |
|
Definition
lysine, Arginine, Histidine
very hydrophilic
have + charge at biologically relevant pH
His ionizable at physiological pH (6.5) so used in catalysis |
|
|
Term
| acidic, negatively charged side groups |
|
Definition
aspartate, glutamate
very hydrophilic
net negative charge at pH 7 ( ability to pick up protons important) |
|
|
Term
|
Definition
confers greater stereo selectivity of substrate
incorporating D-aa's makes it resistant to enzymatic breakdown
adding D-aa to exciting secondary structures reduces stability
important in pharmaceutics and drug design (drugs produced as racemic mix but only one biologically active) |
|
|
Term
|
Definition
| donate H+ or accept lone pair in covalent bond |
|
|
Term
|
Definition
| accept H+ or donates lone pair in covalent bond |
|
|
Term
|
Definition
|
|
Term
|
Definition
Ka= [A-][H+]/[AH] pKa= - log (Ka)
larger Ka/lower pKa = stronger acid |
|
|
Term
| Henderson Hasselbalch equation |
|
Definition
pH = pKa + log [A-]/[HA]
@pH=pKa 50% dissociation |
|
|
Term
|
Definition
weak acid + conjugate base
effective +/- 1 pH unit of pKa
at pH less than pKa protonated form predominates
at pH over the pKa deprotonated form is predominant |
|
|
Term
|
Definition
(pKa1 + pKa2) /2
if triprotic always use pKa's bracketing the zero net charge ion |
|
|
Term
|
Definition
|
|
Term
| peptide bond (amide bond) |
|
Definition
covalent bond between alpha-carbyl group of one AA and the alpha-amino group of another AA
is planar and rigid bond (makes up backbone, side groups make up variable region) due to partial double bond (resonance between O--C--N)
other bonds able to freely rotate=allows different folding
stable= not broken by high heat or high conc. of urea
broken by eco/endopeptidases
equilibrium favors hydrolo |
|
|
Term
|
Definition
named from N-terminus (left) to C-terminus(right)
chain of several AA linked through peptide bonds |
|
|
Term
|
Definition
each AA unit in a polypeptide
each contains a carboyl group (H bond acceptor) and a amino group (H bond donor) |
|
|
Term
|
Definition
opposite sides (alpha-Cs in peptide) of bond
almost all peptide bond in proteins |
|
|
Term
|
Definition
same side of bond
groups attached to alpha-C offer steric hinderance (less stable) |
|
|
Term
|
Definition
| fundamental functional and 3-D structural unit of peptide |
|
|
Term
|
Definition
supersecondary strucures (domains built from)
packing secondary structures connected by loops close to one another |
|
|
Term
|
Definition
made by H-bonds between NH of one AA and COO of another
alpha helix
beta sheets
beta bends |
|
|
Term
|
Definition
stabilized by intrachain H-bonds
all R groups face out
common in globular proteins and DNA binding domains, found in structural fibrous proteins
right handed
COO of residue i bonds with NH of residue i+4 = 3.6residue per turn |
|
|
Term
|
Definition
INTERstrand (5+ AA) H-bonding
R groups point in opposite directions
usually twisted (not flat)
can be : parallel (1-2 bond), antiparallel (1-1 bond), or mixed (referring to interaction of beta strands) |
|
|
Term
|
Definition
H bond between 1st and 4th AA (180deg)
COO of i andNH of i+3
Gly (b/c small) and Pro (b/c cis form makes tight turn)
usually on surface of protein= involved in interactions with other molecules |
|
|
Term
|
Definition
| not regular, periodic structure, but rigid and well defined |
|
|
Term
|
Definition
zinc finger, leucine zipper, helix-turn-helix
[image] |
|
|
Term
| sequence specific DNA binding |
|
Definition
| H-bonding between R gouts and bases (4 different bases present a hydrogen bonding profile for protein to recognize) |
|
|
Term
|
Definition
| (+) R groups form ionic bonds with (-) phosphate backbone of DNA = electrostatic interactions |
|
|
Term
| bacterial DNA binding protiens |
|
Definition
HTH motif,
C-terminal recognition helix fits into major grove of specific sequence of 6-8 bp
N-termina lhelix lies across major grove and makes electrostatic interactions with backbone |
|
|
Term
|
Definition
helix of 30-40 AA with leucine on every 7th, oriented so that on same side of helix
can dimerize so have 2 DNA binding sites
basic AA's bind to negatively charged phosphate of DNA |
|
|
Term
|
Definition
two antiparallel beta strands fold helix with Zn in fold to stabilize (bound to 2 cystine and 2 histadine)
can bind RNA, DNA, and proteins
binds major grove
on HIV virus nucleocapsid (needed for replication)
found on steroid receptors |
|
|
Term
|
Definition
arranged in long strands or sheets
water insoluble
strong but flexible
structural role (collagen, silk, chitin, alpha-keratin) |
|
|
Term
|
Definition
polypeptides folded into globular/spherical shape
water soluble
several types of secondary structure
diverse functions (most common = enzymes)
myoglobin/hemoglobin |
|
|
Term
|
Definition
folded so that hydrophobic R goups on inside and polar on outside
stabilized by H-bonds, hydrophobic interactions, electrostatic interactions (+Lys to - asp)
complex with metal ions
ion-dipole
covalent disulfide bonds (cys-cys) |
|
|
Term
|
Definition
8 helical regions (80%) no beta sheets= very compact
internal mostly (Leu, Val, Phe) non-polar (hydrophobic interactions = stability)
2 internal his important for O2 binding |
|
|
Term
|
Definition
planar porphyrin ring composed of 4 pyrrole rings with N facing the center binding Fe2+
Fe able to bind 6 ligands (5th = proximal his)
O2 is bound non-covalently (stabilized by H-bonds from distal HIs) |
|
|
Term
|
Definition
heterotetramer, 2 alpha and 2 beta (similar tertiary as myoglobin)
internal hydrophobic pocket with heme (F8 = proximal his, E7 = distal his) |
|
|
Term
|
Definition
fibrous protien: triple helical cable, left handed helices twisted into right handed cable
Gly at every 3 position, Pro kink chain to help form helix
Gly-X(often proline)-Y(often hydroxyproline or hydroxylysine)
OH of hydroxypoline give stability via H-bonding, needed for cross-linking
components of skin, connective tissues, b.v. walls, sclera/cornea, matrix of bone
Types I-III = fibril-forming, Types IV-VII network forming |
|
|
Term
|
Definition
| hydroxylation via hydroxylase ans Vit C and Fe2+, O2, and Alpha-ketogluterate |
|
|
Term
|
Definition
| Vit C defficiency= no hydroxylation of proline or lysine = no cross-link of collagen fibers = degeneration of connective tissue (tooth loss) |
|
|
Term
|
Definition
| supporting high tensile strength (skin, bone, tendon, cornea) |
|
|
Term
|
Definition
|
|
Term
|
Definition
| distensible tissues, blood vessels |
|
|
Term
|
Definition
| form sheet that are major part of basement membranes |
|
|
Term
|
Definition
intra- and inter-molecular covalent linking of tropocollagnes catalyzed by lysyl oxidase
inportant for tensile strength and proper functioning of connective tissue |
|
|
Term
|
Definition
| contains Cu2+, oxidatively deaminates lysyl and hydroxylysyl residues to form reactive aldehydes which condense with lysyl residues on nearby strands to form covalent cross-links |
|
|
Term
|
Definition
breakdown collagen
part of matrix metalproteinases |
|
|
Term
| Osteogenesis Imperfecta (OI) |
|
Definition
aka "brittle bone syndrome", heterogenous inherited disorder, bones easily bend and fracture
retarded wond healing, rotated and twisted spine also common |
|
|
Term
|
Definition
presents in early infancy
fracture secondary to minor trauma, long bond deformation
milder cases from AA substitution |
|
|
Term
|
Definition
osteogenesis imperfecta congenita
more sever, neonatal death from pulmonary hypoplasia
found in cartilage, lead to osteoarthritis
most have mutations in gene for pro1- or pro2-alpha chains of Type I collagen. most common is more bulky residue for Gly in every third position. |
|
|
Term
| Ehlers Danlos Syndromes (EDS) |
|
Definition
EDS IV: mutation in collagen Type II (skin, intestines, arteries tear easily)
EDS V: deficiency of lysyl oxidase (thin skin and cardiac valves)
EDS VI: deficiency of lysyl hydroxylase (hyper-extendable joint, eye defects) |
|
|
Term
|
Definition
structural fibrous protiens (alpha in mammals, beta in birds and reptiles)
major proteins of hair and fingernails
alpha helix with globular domain at one end
lots of cystine for disulfide bridges = insoluble and resist stretching |
|
|
Term
|
Definition
reduce to break disulfide bonds
curl
oxidize to reform disulfide bonds |
|
|
Term
|
Definition
| temporary profound hairless from inactivation of one (of dozens) keratin gene |
|
|
Term
| epidermolytic hyperkeratosis |
|
Definition
loss of mechanical integrity of skin= presents as blisters
rare |
|
|
Term
| Post-translational modification |
|
Definition
phosphorylation:of serene, tyrosine, threonine
post-translational modification
glycosylation
hydroxylation: proline and lysine (in collagen)
acetylation: amino terminus
carboxylation: of glutamate (needed for blood clotting proteins)
crosslinking: of two cysteines to make cystine |
|
|
Term
|
Definition
is reversible
kinases add phosphate to hydroxyl groups of serine, theronine, tyrosine
growth factors (insulin) trigger phos of tyrosine
hormones (epinephrin) trigger phos of serene and threonine |
|
|
Term
|
Definition
attach carbohydrates (N-linkage to asparagine, O-linkage to serine, threonine, and 5-hydroxylysine) = glycoprotien
common in plasma membranes, extracellular proteins, and blood plasma |
|
|
Term
|
Definition
partial transfer of electrons from Fe to O2. = Fe3+ and O2- (superoxide ion)
reactive oxygen species that can damage DNA
if superoxide ion released Fe3+ will not bing O2
structure of Mb stabilizes O2 so superoxide less likely to be released. |
|
|
Term
|
Definition
25,000 times more strongly in isolated heme
b/c CO likes linear conformation and O2 likes bent
in polypeptide environment CO is bent conformation (distal His prevents linear rearrangement, with distal His CO takes 1% of Mb without distal His takes >99% of Hb) |
|
|
Term
|
Definition
fractional saturation (Y) vs. partial pressure of O2 (concentration)
Mb= hyperbolic (high affinity b/c need to extract from low conc in blood)
Hb= sigmoidal (weaker binding than Mb) shows cooperatively (steepest part of curve is at concentration 20-40 torr conc. =difference between exercising and resting muscle tissue)
difference so that Mb can take O away from Hb in tissues where pO is low (and Hb can let go) |
|
|
Term
|
Definition
deoxy form (low affinity)
lower pH and high CO2 in tissues/arteries = promote O2 release and binding of CO2 |
|
|
Term
|
Definition
oxy form high affinity
oxygenation in lungs favors oxy form = stim CO2 release |
|
|
Term
|
Definition
| when forming bicarbonate and when reacting with Hb further stim O2 release and CO2 binding |
|
|
Term
|
Definition
| activity modulated by allosteric effectors |
|
|
Term
| allosteric effectors of Hb |
|
Definition
pO2, pH, pCO2, 2,3-BPG
Mb NOT influenced by allosteric effectors |
|
|
Term
|
Definition
% saturation curve shift to LEFT (greater O2 affinity) by ^ pH and lower pCO2
% saturation curve shift to RIGHT (decreased O2 affinity) by lower pH or increased pCO2 |
|
|
Term
| 2,3-BPG (bisphosphoglycerate) |
|
Definition
negatively charged (2 phosphate groups and 1 carboxyl group)
in erythrocytes
binds tightly to puka in deoxyHb (stabalized by + charge of 2 His and 1 Lys per beta chain)
poor binding affinity for oxyHb because puka too small
bind to beta chains (1 BPG/Hb tetramer), not where O2 binds
= dynamic competition for O2 binding
more BPG = more O2 released at peripheral tissues
one way to increase O2 delivery at high altitudes.
shift binding curve right
part of feedback loop to prevent hypoxia |
|
|
Term
|
Definition
dissolved in plasma = 7-10%
bound to Hb = 20%
bicarbonate ion in plasma = 70% |
|
|
Term
|
Definition
CO2 + H2O = H2CO3 (carbonic acid) = (H+) + HCO3- (bicarbonate ion)
happens in RBCs
catalyzed by carbonic anhydrase
is reversible (reverse run at lungs to release CO2)
the release of H+ = drop in pH = stabilize T state |
|
|
Term
|
Definition
| Cl- moves into RBC from plasma as bicarbonate ions (- charge) move out of RBC into plasma |
|
|
Term
| bicarbonate-carbonic acid buffer systme |
|
Definition
resists changes in pH ( carbonic acid = weak acid, bicarbonate ion = conjugate base)
if excess H+, removed by binding with HCO3-
in H+ to low, carbonic acid dissociates |
|
|
Term
|
Definition
CO binds 10^4 times more than O2
traps Hb in R-state (shift curve left) = O2 already bound not released (carboxyhemoglobin) half life 4-5 hrs
treat with hyperbaric O2 (100% O2) = pO2 of 2000 and 4000 mmHg (arterial and tissue) to displace CO so half live <20 min |
|
|
Term
|
Definition
lone pair on N-terminus of globin reacts with CO2 to form carbamate COO--NH--R + H+
N-termini lei at interface between alpha/beta dimers
negative charge helps stabilize T-state via ion interactions (T-state likes charged, R likes non charged) = favor O2 release |
|
|
Term
| Bohr Effect tissues vs. lungs |
|
Definition
Tissues: Lungs:
high CO2 low CO2
lower pH higher pH
affinity for O2 decreases affinity for O2 increase
O2 released O2 binds Hb
T-state favored R-state favored |
|
|
Term
|
Definition
protonated His side chain
+ 1 overall charge
protonation results in dissociation of O2 (= T-state)
contribute to T-state Bohr effect |
|
|
Term
|
Definition
His side chain deprotonated
zero net charge
pKa = 6.0 |
|
|
Term
|
Definition
interface between alpha1beta1 and alpha2beta2 are very strong (30 residues) and move little
interface between alpha1beta2 and alpha2beta1 have only 19 residues = MAJOR SHIFTS
T-state stabilized by ionic interactions between C5 Lys on alpha and HC3 His on beta and FG1 Asp on beta |
|
|
Term
| Heme conformational changes |
|
Definition
deoxy = nonplanar, Fe ~0.6 A out of plane (electron clouds of Heme and proximal His push each other apart)
oxy: when O2 bound to Fe, porphyrine ring become planar= His is pulled closer shifting the AA nearby |
|
|
Term
| R state conformational changes |
|
Definition
when proximal His is pulled closer to O2 bound heme the F helix moves promoting subunit rotation and rearrangement of alpa1beta2 interface to favor R-state
salt bridges, & H-bonds holding C-terminus in alpha and beta chains broken in R-state |
|
|
Term
|
Definition
R; T:
more compact has additional salt
CO2- termini free rotation bonds
O2 sites have higher affinity CO2- terminal salt link
fewer steric repulsions
better Fe-O2 bond length
shortened Fe-N porphyrin bonds
15 deg rotation of alpha1beta1 relative to a2b2
change at interface between a2b1 and a1b2 |
|
|
Term
|
Definition
acidic conditions: Lys, His, Asp form 2 salt bridges to stabilize T-state (Lys on alpha to C-terminal of beta, protonated His on B, + charge, to Asp on beta)
basic conditions: His is deprotonated and cannot bridge with Asp
(T-state release O2 b/c low affinity) |
|
|
Term
|
Definition
fetal hemoglobin: gamma chains instead of beta, has higher O2 affinity
made in bone marrow in forest few weeks
HbF gradually replaced by HbA (manufacture in bone marrow starting in 8th month of pregnancy) |
|
|
Term
|
Definition
have Ser instead of His in 2,3-BPG binding site
Ser is non-charged so will not bind 2,3-BPG = more in R state = higher O2 affinity |
|
|
Term
| Sickle cell anemia (Hb S) |
|
Definition
single AA substitution of beta subunit: Val for Glu
Val has hydrophobic side chain, Glu has negative charge
Val causes sticky point on deoxyHb where molecules aggregate
symptoms: weak, SOB, fragile sickle cells (anemia), blocked capillaries, abnormal organ function, short RBC life (<20 days compared with 120)
makes deoxyHb insoluble
Phe and Leu on beta subunit at surface bind (hydrophobic interaction) to valine on other beta; in oxyHb Phe and Leu not at surface so not aggregate = O2 binding and allosteric prop retained.
Confers advantage to fight Malaria; shorter life span = parasite cannot complete development |
|
|
Term
|
Definition
lysine sub for Glu
homo relatively mild, chronic hemolytic anemia
no specific therapy |
|
|
Term
|
Definition
hereditary hemolytic disease; either a or B chain defective = low levels of functional Hb and decreased RBC (= anemia, fatigue, pale skin, liver malfunction)
alpha-thalassemia: a chain not produced, only b-chain tetramers= high O2 affinity but no cooperativity
beta-thalassemia: no B chains, a chains form insoluble aggregates, precipitate inside imature RBCs (=anemia)
Thalassemia major or Cooley anemia = most severe form (of beta-thalassemia) |
|
|
Term
|
Definition
| more stable than unfolded = -G = spontaneous (non-spontaneous if +G) |
|
|
Term
|
Definition
| electrostatic effects (H-bonds, salt bridges), salvation/desolvation of charged residues, van der Waals interactions |
|
|
Term
|
Definition
| entropy (hydrophobic effect), conformational entropy (degree of freedom) |
|
|
Term
|
Definition
free energy of folding
G is often small (-5 to -15 kcal/mol) = marginally stable
loss of S is large when fold
H gains(H-bonds, slat bridges, electrostatics) barely overcome loos of S |
|
|
Term
|
Definition
major stabilizing force of protein structures, driven by the increase in entropy of water (loss of S too much to make G negative by itself, but add hydrophobic effect G negative = spontaneous)
why/how?: no H-bonds with non-polar side chains so make "cage" around (decrease entropy of water) if side chains cluster into interior loss of entropy reduced (preferred) |
|
|
Term
| non-covalent folding forces |
|
Definition
H-bonds: (1-7 kcal/mol, distance between 2.7-3.1 A): H covalently bound to O,N makes bond with another O,N
Ionic interactions: 1-6kcal/mol, opposite charges attract, can be dissolved by water
Hydrophobic interactions: 2-3 kJ/mol (4.2 kJ/kcal)
van der Waals interactions: <1kcal/mol transient dipole-dipole |
|
|
Term
|
Definition
conformation of protein disrupted by environmental changes (heat) or chemical agents (detergents)
causes a loss of biological activity |
|
|
Term
|
Definition
| restoration of native conformation when denaturation agents removed |
|
|
Term
|
Definition
denaturing agent; disrupt non-covalent bonds within protein ( hold tertiary and quaternary structure)
guanidinium chloride is also denaturing agent |
|
|
Term
|
Definition
| reducing agent (reduces disulfide bridges): donate electrons from lone pairs |
|
|
Term
|
Definition
primary structure dictates 3_D structure
folding is spontaneous and driven by free energy gained by adopting more stable form
denaturing is reversible
correct disulfide bonds form only after protein folds into correct form
only one correct form has enzymatic activity |
|
|
Term
|
Definition
| folded form has lowest free energy |
|
|
Term
|
Definition
help overcome kinetic barriers to folding, increase rate of correct folding and prevent formation of incorrectly folded intermediates
can bind to unassembled protein subunits (to prevent incorrect aggregation)
most are heat shock proteins to repair damaged or partially denatured proteins
require ATP for protein binding |
|
|
Term
| unfolded protein response |
|
Definition
| if protein is misfolded it is transported out of ER, where it is ubiquinated, then degraded by proteasomes |
|
|
Term
|
Definition
| deletion mutation (Phe) is chloride channel protein leads to improper folding and reduced Cl- conductance |
|
|
Term
|
Definition
| (Alzheimer's, prion diseases, mad-cow) protein misfiling or defective processing, leading to aggregate and formation of insoluble plaques |
|
|
Term
|
Definition
CJD (Creutzfeldt-Jakob disease), Spongiform Encephalopathies (include mad cow), Alzheimer Disease, Parkinson Disease
partly folded or misfiled polypeptides or fragments may sometimes aggregate
aggregates vary in size, from soluble dimer/trimers to insoluble fibrillar structures (amyloid), both can be toxic
protein aggregates = amyloid plaques/tangles form lesions on the brain (Alzheimers), liver or heart
common structural feature: central core of beta sheets known as a "cross-beta" structure |
|
|
Term
|
Definition
beta-amyloid fibril component
symptoms: memory loss, dementia, impairment of cognition and behavior.
Not transmissible
intracellular aggregates of Protein called "Tau"
extracellular plaques = aggregates of beta-amyloid peptides (40-42 residues, derived from cleavage of amyloid precursor protein APP) attached to p.m. of neurons
has flexible structure = make aggregates
plaques develop in hippocampus |
|
|
Term
| Spongiform Encephalopathies |
|
Definition
prion proteins
Bovine spongiform encephalopathy (mad cow), scrapies (sheep), CJD (human).
fatal, neurodegenerative, "holes" appearing in brain
infectious, caused by prion (proteinaceous infections only) protein of PrP (diseased PrP sc)
arggregates resistant to treatment by most protein-degrading enzymes acquired by infection, inheritance (dominant), spontaneously |
|
|
Term
|
Definition
alpha-synuclein
degenerative disorder of CNS, impairs motor skills, speech, and other functions
lesions form in dopaminergic neurons in negra of brain= muscle rigidity and resting tremor
due to insufficient dopamine production (from loss of dopamine-producing cells)
treatment: L-DOPA (levodopa)
L-dopa is a naturally found in brain, moderately effective treatment for Parkinsons |
|
|
Term
|
Definition
- dopamine, norepinephrine, epinephrine = biologically active amines ("flight or fight" hormones released from adrenal glands)
- dop and NE are neurotransmitters in brain and ANS
- all are water soluble and 50% bound by plasma proteins
contain a catechol
[image]
and an ethylamine moiety
|
|
|
Term
|
Definition
- functions: regulate CHO and lipid metabolism
- released from vesicles in adrenal medulla in response to fright, exercise, cold, low blood glucose
- increase degredation of glycogne and triglycerol, increase blood pressure and cardiac output
- endogenous ligands
|
|
|
Term
|
Definition
- low lipophilicity
- fast enzymatic degradation by COMT and MAO= limited clinical app
|
|
|
Term
|
Definition
- sympathomimetic monoamine dervied from Phe and Tyr
- powerful vassopressor (increase b.p.)
- increases heart rate and stroke volume
- dilates pupils
- stim glycogen breakdown
- increases rate of glycolysis in muscles and release of glucose from liver
|
|
|
Term
|
Definition
- E binds to β-adrenergic receptor (plasma protein)
- bound receptor replaces GDP with GTP on Gs activating Gs
- alpha subunit moves to adenylyl cyclase and activates it
- AC catalyzes formation of cAMP
- cAMP activates PKA
- PKA phosphorylates cellular proteins=cellular response
- cAMP degraded
increased cAMP promote relaxation of bronchial muscles |
|
|
Term
biosynthesis of catecholamines
|
|
Definition
- tyrosine is hydroxylated to form L-DOPA; rate limiting step
- L-dopa is decarboxylated by DOPA decarboxylase to form dopamine
- dopamine is hydroxylated to form norepinephrine(NE)
- N-methylation of NE via S-adenosylmethionine forms epiniphrine(E)
|
|
|
Term
|
Definition
monoaminooxidase
sustrate: aliphatic amines
[image]
method of breakdown: deamination |
|
|
Term
|
Definition
catechol-O-methyltransferase
substrate: catechol moiety
method of breakdown of CAs: methylation |
|
|
Term
|
Definition
E and NE: 3-mthoxy-4-hydroxymandelic acid
Dopamine: homovanilic acid
excreted in urine |
|
|
Term
| re-uptake of neurotransmitters |
|
Definition
- after presynaptic release of neurotransmitter from vessicle about 80% if taken back into pre-synaptic neuron and only 20% are effectors for the post-synaptic neuron
- allows recycling, and regulates levels present in synapse, and controls how long signal lasts
- specific transporters are needed (nt are too large and hydrophilic to diffuse)
|
|
|
Term
|
Definition
soluble in organic solvents
structural components of membranes
provide energy reserves (triacylglycerols)
lipids and derivatives serve as vitamines
solubilization aided by lipophilic bile acids |
|
|
Term
|
Definition
terminal carboxylic acid moiety and long saturated or unsaturated carbon chains
function as major energy sources
examples: Stearic Acid (C-18 unsaturated), Oleic Acid (C-18 monounsaturated)
naturally occurring unsaturated FAs have cis configuration = kink in chain |
|
|
Term
|
Definition
formed from FAs and glycerol 3-phosphate
triglycerides formed from a glycerol esterified with 3 FAs |
|
|
Term
|
Definition
| built from FAs and sphingosine (long chain alcohol carrying an amine group) |
|
|
Term
|
Definition
| characteristic 4 fused rings structure |
|
|
Term
|
Definition
| units joined in head-to-tail was (make up terpenes, vit A,E, and K) |
|
|
Term
|
Definition
human body cannot synth unsaturated FAs
must be obtained through diet
long chain polyunsaturated derived from Linolenic, linoleum, and oleic acids
support cardiovascular, repro, immune, and nervous system
needed to manufacture and repair membranes
omega-6 and -3 (# refers to C that first double dond is on)
omega-6: thrombotic/inlammatory
ex: linoleic (corn/sunflower oil), derive Arachidonic acid (meat,eggs,brains), derive prostaglandin E2
Omega-3: lower thrombotic/inflammatory
ex: alpha-Linolenic (flaxseed/canola oil), Eicosapentaenoic acid EPA, Docosahexaenoic acid DHA (fish oil) |
|
|
Term
|
Definition
aka eicosanoids (reflect root 20 C chain FA)
extremely potent, wide rang of effects physiologic (inflammatory) to pathologic (hypersensitivity)
ensure gastric integrity, renal function, regulate smooth muscle contraction/b.v. diameter, maintain platelet homeostasis produced in very small amounts in tissues (not glands) = act locally
not stored, extremely short half life
actions mediated by membrane G prtein coupled receptors |
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Term
| triacylglycerol (triglycerides) |
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Definition
3 Oh groups of glycerol esterified w/ FAs
form oily droplets in cytosol, excellent stored energy
solid at RT = saturated acid rich, fats (animals)
liquid at RT = unsaturated rich, oils (plants, fish) |
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Term
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Definition
| has polar "head" group (phosphate, sulfate, CHO) and non-polar tail |
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Term
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Definition
composed of alcohol attached to diacylglycerol or sphingosine by a phosphodiester bridge
amphipathic
predominant in cell membranes |
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Term
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Definition
derived from glycerol
simple = phosphatidic acid (PA), diacylglycerol with phosphate group on 3rd C
add choline to phosphate group = phosphatidylcholine (lecithin) |
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Term
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Definition
sphingomyelin: amino group of sphingosine linked to FA by amide bond, primary OH group of sphingosine is esterified to phosphoric choline
major component of myelin sheath
an amino alcohol that contains a long unsaturated hydrocarbon chain |
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Term
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Definition
absent from prokaryotes but is found to varying degrees in all animal membranes
consitutes 25% of membrane lipids in certain nerve cells, but absent from some intracellular membranes
in membranes oriented parallel to FA chains = OH groups interact w/ polar groups of nearby phospholipids |
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Term
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Definition
all have tetracyclic ring system
many hormones
major subgroups: cholesterol, bile acids
side groups on C 3 and 17 |
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