protein oral topics Flashcards
oxidative de-amination of D-aa
peroxisomes is an organelle that contain the aerobe D-amino acid oxidase, used as a defence system to generate hydrogen peroxide - antimicrobial
what happens to N-free carbon chain of AA (after de-amination)
ketogenic and/or glucogenic aa’s are made. these enter the TCA cycle at different places to be utilized
which are ketogenic amino acids
leucine
- can be converted to acetylCoA
- if no OAC is present, leu will enter ketogenesis (acetoacetate) instead
which are glucogenic amino acids
if the diet lacks carbs, aa’s are converted into pyruvate or OAC to be used in TCA, make glucose is goal
(ala, arg, asn, asp, cys, glu, gln, gly, his, met, pro, ser, thr, val)
gluco or ketogenic amino acids
can form partly acetylCoA, partly OAC
Phe, ile, trp, tyr, lys
schiff base
using the cofactor PALP to make a imine link (N=C) btw PALP and the aa and then transferring the imine bond to the aa using water, creating a alpha-ketoacid, and vice versa an amino acid
essential amino acids
THILLT MVP
P - phenylalanine, T - threonine, tryptophan
what are biogenic amines
decarboxylated amino acids
- synth in microbial, vegetable and animal metabolisms. In food and beverages they are formed by the enzymes of raw material or are generated by microbial decarboxylation of amino acids
histidine as biogenic amine
histamine
- capillary dilator, allergic reactions (H1-rec)
- secretion of gastric juice (H2-rec)
Lysine as biogenic amine
cadaverine
- produced by bacterium, responsible for foul smelling odor of dead flesh
ornithine as biogenic amine
putrescine
- produced by bacterium, responsible for foul smelling odor of dead flesh
Tryptophan as biogenic amine
tryptamine
- neurotransmitter; SM contraction
serotonine
- neurotransmitter; SM contraction
aspartate as biogenic amine
B-alanine
- synthesis of pentochloric acid(?)
- used in synth of coenzyme A
coenzyme A
synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle
- made from vit B5
glutamate as biogenic amine
GABA
- inhibitory neurotransmitter
serine as biogenic amine
ethanolamine=cholamine
- made of phosholipids used in biological membranes
cysteine as biogenic amine
cysteamine
- vasoconstrictor, SM constrictor
- used in synth of pantothenic acid (Vit B5)
cysteic acid -> taurine
- bile salt synthesis, essential for carbs
tyrosine as biogenic amine
tyramine
- neurotransmitter, smooth muscle contraction
DOPA
- dopamine -> neurotransmitter, hormone
carnosine and anserine effect
antioxidants, buffering of lactate in muscle
carnosine made of and found where
B-ala and His
- muscle and brain of mammals
anserine made of and found where
B-ala and CH3-His
- muscle and brain of birds
interspp: essential aa’s
ru: all are synth in the rumen by microbes
birds: gly, arg
Fe: taurine (cys)
glutathione effect
in RBC removes harmful peroxides via glutathione peroxidase
Gamma glutamoyl cycle
transfer aa across membrane to GGcycle, where the aa becomes an acceptor for the glutamoyl moiety, the glutathione formed will be an antioxidant (reduced, -H)
PPP supply RBC with NADPH+H+ to maintain its reduced state.
what would happen W/O the GGcycle
incr. H2O2 -> MetHb
production of ammonia
- oxidative deamination
- degr. of biogenic amines
- absorption from the GI tract (mainly ru)
detoxification of ammonia
- urea cycle: liver
- Glutamine synth from glu: liver
- Asparagine synth from asp: liver
- L-glu synth from alpha-ketoglutarate: liver
- purine synth -> uric acid
PALP is used
as cofactor in transamination, deamination nd decarboxylation reactions
TPP cofactor is used in
cytosol for the activity of transketolase and in the mitochondria for the activity of pyruvate-, oxoglutarate- and branched chain keto acid dehydrogenases
biotin
as cofactor in carboxylation reactions (carboxylases)
urea cycle in ru
ruminohepatic system
- bacterial metabolism play a key role
- non-protein N - bacterium to make protein or ammonia
hemoglobin structure
4 heme, 4 pp chains = hemoglobin
fetal: 2 alpha, 2 gamma
adult: 2 alpha, 2 beta
hemoglobin role
- bind 4 oxygen used in resp chain of tissues
hemoglobin binding of oxygen
- confirmational change: from tense to relaxed form, makes binding of 2nd ox easier
inhibiting the binding of oxygen and co2 how
200-300x higher affinity for CO than O2 -> hb can no longer carry O2 or CO2
methemoglobin: Fe³⁺ instead of Fe²⁺, ox binding not possible
the first 2 steps of hemoglobin synthesis: where, inhibitiation?
1st: mitochondrion
2nd: cytoplasm
ALA dehydratase is inhibited by lead
where is iron stored after degr. of hb
phagocytes as Fe³⁺
- speen, liver and bone marrow
icterus
high conc. of bilirubin 1/2 in the blood
- prehepatis (hemolysis)
- hepatic (liver disease)
- post hepatic (gall stone)
myoglobin composition
1 heme and 1 polypeptide
- hyperbolic saturation curve as skeltal mm. needs oxygen quicker than other tissues
paralytic myoglobinuria
in horser esp.: genetic background
- muscle cell, kidney damage
- myoglobin in circulation -> urine -> black urine
cytochromes
found in respiratory chain as electron carrier, e.g. - P450:
heme as cofactor; metabolize potentially toxic compounds, including drugs and products of endogenous metabolism such as bilirubin, principally in the liver.
catalase and peroxidase function
antioxidant controle prevents Fe²⁺ -> Fe³⁺ in hb making hemin, which is not able to carry O2 or CO2
what can iron be stored as
hemosiderin: not water soluble
ferritin: water soluble
iron sources
Fe²⁺
Fe³⁺ from plants
heme: Fe²⁺
what is needed to transport iron on the apical side of enterocytes
ascorbic acid - vit. C
hepicidin
inhibit ferroportin during inflammation, leading to an decr. in RBC
iron deficiency leads to, where is iron lost
hair loss, nail loss
iron loss through
- urine, sweat, milk, blood loss
