BCH Exam 3

Name the non-essential Amino Acids

ANDES

Alanine is made from what compound

Pyruvate

Alanine is made from what enzyme and chemical rxn

ALT, transamination

Asparagine is synthesized directly from what compound; which is made from what

aspartate, oxaloacetate

The first step of Asparagine synthesis requires what enzyme and substrate

AST; OAA

The enzyme the catalyzes the synthesis of Asn

Asparagine synthetase

The enzyme the catalyzes the synthesis of Asn requires

Aspartate _{(from OAA)} , Glutamine & ATP

The enzyme the catalyzes the synthesis of Asn performs what rxn type

amidation

Asparagine synthesis requires what key Nitrogen carrier/donor

Glutamine

Asparagine synthetase and CPS-II uses what strategy to prevent ammonia escape in the environment when transferring the amino group of glutamine to aspartate

Ammonia tunnel

Enzymes using ammonia tunnels

Asparagine synthetase, CPS-II

Aspartate can be synthesized from what two Substrate/Enzyme pairs?

OAA(+Glu)/AST; Asparagine/Asparaginase

Asparaginase catalyzes what type of chemical reaction to generate _______

deamidation, aspartate

Asparaginase activity releases what byproduct

Ammonia

The ammonia released by Asparaginase can be assimilated by what three enzymes

Glutamate dehydrogenase (to make Glutamate); Glutamine Synthetase (to make glutamine); CPS-I (to make Carbamoyl Phosphate)

Which of the ammonia-assimilating enzymes do not require ATP

GDH (requires NADH)

Method of Aspartate synthesis that does not release ammonia is catalyzed by; what are the reactants

AST; OAA+Glu

Three enzymes that make glutamate

Transaminases (like ALT/AST), GDH, Glutaminase

Glutaminase catalyzes what type of rxn

Hydrolysis (so it requires H2O)

Arginine is made by what enzyme; what byproduct is produced along with it

Argininosuccinate Lyase; Fumarate

Creatine Synthesis requires what THREE amino acids (single letter codes)

GRM

Creatine Synthesis requires methionine for what purpose

methyl group donation via SAM

In muscles, creatine is…

phosphorylated by creatine kinase

In muscles, creatine becomes

phosphocreatine

Creatine

Short term energy buffer in muscle cells

phosphocreatine

A small amount of creatine and phosphocreatine constantly and spontaneously cyclize to form this waste product in the muscles, which travels through the blood, and is filtered out into urine by the kidney. High levels in the blood = kidney problems

creatinine

Three-quarters of ingested phenylalanine is going to be hydroxylized by what to make what

phenylaanine hydroxylase, tyrosine

Phenylalanine hydroxylase catalyzes the ________ at ______ of the phenyl group of phenylalanine to form ____________

hydroxylation, C4, tyrosine

Tyrosine formation requires what enzyme and cofactor

Phenylalanine hydroxylase, BH4

BH4 is a necessary cofactor for the synthesis of

tyrosine, dopamine, serotonin, noradrenaline

BH4 is synthesized from

GTP

SAM/Ado-Met is synthesized from

Methionine & ATP

What serves as the body’s primary activated methyl donor

SAM/Ado-Met

Methionine Synthase: reactants, products; cofactor

Homocysteine +5-Methyl THF, Methionine; B12

A

SAM (AdoMet)

B

CH3

C

Methyltransferase

D

SAH (AdoHcy)

E

Adenosyl homocysteinase

F

Adenosine

G

Homocysteine

H

Methionine Synthase

I

THF

J

B12

K

5-Methyl THF

L

Methionine

M

Methionine Adenosyltransferase

N

ATP

Glutathione is a tripeptide composed of what three amino acids (1 letter codes)

ECG

Glutathione is important for

antioxidant reduction/defense

Glutathione in its oxidized form is what kind of structure and contains what key bond

tripeptide dimer; disulfide (bridge)

Amino Acids that are Neurotransmitters

EDSG (Excited Doctors Start Gasping)

Excitatory Amino Acid Neurotransmitters

E, D

Inhibitory Amino Acid Neurotransmitters

S, G

Serine as a neurotransmitter is special because it is in what form

D-Serine

Term for neurotransmitters involved in reward, attention, arousal, and the fight-or-flight response

Catecholamines

Catecholamines include

dopamine, norepinephrine, epinephrine

Major inhibitory neurotransmitter in the CNS that helps reduce neuronal excitability and prevent excessive nerve signaling

GABA

GABA is made from

glutamate

Neurotransmitter involved in regulating mood, sleep appetite, digestion, blood clotting, and sexual desire

Serotonin

Serotonin is derived from

Tryptophan

Catecholamines are derived from

tyrosine

The conversion of Norepinephrine to epinephrine is what type of reaction; meaning it requires

Methylation, SAM

The conversion of Glutamate to GABA is what type of reaction; meaning it requires

Decarboxylation; PLP (vitamin B6)

These reactions all require what critical cofactor

PLP (vitamin B6)

Name the reactant/product pairs in the three decarboxylation reactions (PLP-dependent) where an amino acid builds a neurotransmitter

DOPA→Dopamine, Glutamate→GABA, 5-HyTrp→Serotonin

Name the amino acids that make neurotransmitters and the neurotransmitters they form

Tyrosine/Epinephrine, Glutamate/GABA, Tryptophan/Serotonin

SAM is required in what step where an amino acid is used to build a neurotransmitter; what is the original amino acid used in this pathway

Norepinephrine→Epinephrine; tyrosine

Nucleotides three components

Pentose, Nitrogenous base, phosphates

Nucleoside

Nucleotide without phosphate

Purines

AG

Pyrimidines

CUT

Uracil (U)

Thymine (T)

Adenine (A)

Guanine (G)

Only nitrogenous base that does not contain a carbonyl group

Adenine

dTMP

UMP

CMP

dCMP

AMP

dAMP

CPS-II reaction

Glutamine + CO2 + 2 ATP → Carbamoyl phosphate

Purine synthesis starts with

ribose-5-phosphate

Pyrimidine synthesis starts with making the

base

Three amino acids used in nucleotide synthesis

Gln, Gly, Asp

Amino Acid used in purine but not pyrimidine synthesis

Glycine

PRPP

An intermediate synthesized from ribose-5-phosphate (from the pentose phosphate pathway)

PRPP

PRPP is synthesized from

ribose-5-phosphate (from the PPP pathway)

PRPP is synthesized by

PRPP Synthetase

PRPP Synthetase requires

ATP

Key intermediate that provides the ribose + phosphate groups for all nucleotides

PRPP

CPS-II acts in what cellular component

Cytosol

The 1st committed step of pyrimidine synthesis is catalyzed by

CPS-II

CPSI and CPSII both require what to make what

ATP, Carbamoyl Phosphate

CPS-II nitrogen source

Glutamine (NOT ammonia)

CPS-II allosteric activator

PRPP and ATP