BIOCHEM Exam 3

sodium, depolarization

excitatory neurotransmitters open — channels and promote membrane — in another cell either a neuron or effector cell

chloride, inhibiting

inhibitory neurotransmitters open — channels and make the membrane potential in the postsynaptic cell more negative thereby — membrane depolarization

nitrogen, neuropeptides

neurotransmitters fall into 2 categories: small — containing molecules, and —

glutamate, glycine, dopamine, GABA, norepinephrine

major small nitrogen-containing neurotransmitters include: —, —, —, serotonin, —, Acetylcholine, —, histamine

glucose, ketone bodies

in the fasting state in the liver, carbons from degraded AAs are used to produce — and — —

glycogen, triacylglycerols

in the fed state in the liver, carbons from degraded AAs are used to produce — and —

liver

the — is the only tissue containing all the pathways of AA synthesis and degredation

serine, glycine, cysteine, alanine

What are the 4 AAs synthesized from glycolytic intermediates?

serine

glycine is synthesized from — in a reversible reaction

oxalate

about 40% of — formed in the liver is the result of glycine degradation

cystathione B synthase

serine + homocysteine → cystathione

methionine

the homocystine used in cystine synthesis comes from — an essential AA

cystathionase

cystathionine → cysteine and a-ketobutyrate

homocystinemia

A deficiency of cystathionine B synthase that is associated with cardiovascular disease

tyrosine hydroxylase

rate limiting step of catecholamine (NTs syn from L-tyrosine) synthase:

L-tyrosine → DOPA

dopa decarboxylase

catecholamine synthase: DOPA → dopamine

Dopamine β-hydroxylase

Catolamine synthesis: dopamine → norepinephrine

phenylethanolamine N-methyl-transferase

Catolamine synthesis: norepinephrine → epinephrine (typically occurs in the adrenal medulla)

Dopamine, norepinephrine, epinephrine

What NTs is tyrosine used to synthesize?

serotonin, melatonin

What NTs is tryptophan used to synthesize?

catecholamine

— is NTs formed by L-tyrosine

reuptake, diffusion

catecholamine action is terminated by — into the presynaptic neuron and — away from the synapse

COMT, MAO

What are the 2 enzymes involved in the degradation of catecholamines?

Vesicles

MAO inactivates any catolamines that are not in —

tryptophan hydroxylase, dopa decarboxylase

— — catalyzes the first step of serotonin synthesis and — — catalyzes the second

MOA-A

Serotonin is inactivated by —

choline acetyltransferase

Acetyl CoA + choline →acetylcholine

Acetylcholinesterase

Acetylcholine is inactivated in the synaptic cleft by —

Cholinergic

Unless acetylcholine is inactivated by acetylcholinesterase it will continue to activate the postsynaptic — receptors

Aging

The irreversible inhibition of Acetylcholinesterase by water binding

2-PAM, atropine

DuoDote treats a cholinergic crisis with — and —

Atropa Belladonna

Atropine comes from — — (Deadly nightshade)

Antagonist

Atropine is a competitive — of cholinergic receptors

Acetylcholinesterase

2-PAM binds to — changing the conformation of the enzyme and protecting it from aging by releasing the inhibitor from the enzyme preventing irreversible inhibition

GABA, glycine

What are the major inhibitory NTs?

α-ketoglutarate

Glutamate is typically synthesized by —

glutamic acid decarboxylase (GAD)

glutamate → GABA

GABA, Glutamine, glutamate

α-ketoglutarate is used to synthesize what 3 NTs?

glycine

— is the major inhibitory NT in the spinal cord

glutamine

— serves as the transporter of glutamate between cells in the CNS

cholinergic crisis

symptoms such as bradycardia, labored breathing, excessive salivation, and increased bowel sounds are the clinical signs of a — —

methionine, cystine

homocystinemia is treated by having a low protein diet and a diet high in — and —

phenylalanine hydroxylase

phenylketonuria is an autosomal recessive genetic disorder caused by a deficiency in — —

phenylalanine, tyrosine

phenylketonuria is treated by consuming a diet low in — and high in —

branched chain a-keto acid dehydrogenase

MSUD is a deficiency of — — — — — complex

valine, leucine, isoleucine

what are the 3 AAs that need to be avoided in a persons diet to treat MSUD?

Lysosomal protein, ubiquitin proteosome

What are the 2 systems involved in degrading proteins to free AAs? — — turnover system and the — — pathway

nitrogen balance

the changes in the relative amounts of free AA in the pool of circulating AA

greater

positive nitrogen balance indicates that the amount of protein ingested is — than the amount of protein degraded (excess AA can be oxidized in liver or degraded in the feces)

less

in a negative nitrogen balance the amount of ingested protein is — than the amount of proteins degraded by the cell in normal turnover → the amount of circulating AA will decrease over time

urea

in the liver, ammonia from the amine groups of AAs is converted to — and excreted in the urine

Kwashiorkor syndrome

A disease characterized by sufficient calorie intake but insufficient protein causing ascites (specifically caused by a decrease in Albumin)

cachexia

a disease of extreme oxidation of AA obtained from muscle proteins leading to muscle wasting often associated with diseases such as cancer

alanine

What AA transports amino groups from muscle cells to the liver?

glutamine

What AA transports amino groups from everywhere but muscle to the liver?

aminotransferase

in the liver the first step of processing of an amine group is:

amine group + a-ketoglutarate → glutamate

ALT (alanine aminotransferase)

— is found in many tissues and catalyzes the

transfer of an amine from alanine to α-ketoglutarate

to form pyruvate and glutamate