NBCE - Part 1 / Biochemistry - Irene Gold review QUESTIONS AND ANSWERS COMPLETE (2023/2024)

NBCE - Part 1 / Biochemistry - Irene

Gold review

All amino acids are L-form except? ANSWER- glycine

T/F - All amino acids are amphoteric? ANSWER- T

What does amphoteric mean? ANSWER- Can act as either an acid or a base

What are the essential amino acids? ANSWER- P = phenylalanine

V = valine

T = tryptophan

T = threonine

I = isoleucine

M = methionine

H = histidine

A = arginine

L = leucine

L = lycine

T/F - histidine is essential in a child but not an adult? ANSWER- True

What are the purely ketogenic amino acids? ANSWER- Leucine and Lysine

What amino acid is the precursor for carnitine? ANSWER- Lysine

What is the function of carnitine? ANSWER- takes FA into mitochondria for betaoxidation

What are the aromatic amino acids? ANSWER- phenylalanine

tyrosine

tryptophan

What is unique about tryptophan? ANSWER- It has an indole ring

What are the sulfur-containing amino acids? ANSWER- cysteine, methionine, and

cystine

2 cysteines linked together make what? ANSWER- cysteine

What are the branched chain amino acids? ANSWER- isoleucine, leucine and valine

Maple syrup urine disease is a defect in? ANSWER- the bodies ability to breakdown

branched chain amino acids

What are the acidic amino acids? ANSWER- aspartate and glutamate

What does aspartame contain that makes it neurotoxic in excess? ANSWER- aspartic

acid (aspartate)

What are the basic amino acids? ANSWER- histidine, lysine and arginine

T/F - basic amino acids have the smallest positive net charge at NORMAL pH of blood?

ANSWER- F - greatest positive net charge

Wheat is lacking in which aa? ANSWER- lysine

Rice is lacking in which aa? ANSWER- lysine

Legumes are lacking in which aa? ANSWER- tryptophan

Maize is lacking in which aa's? ANSWER- lysine and tryptophan

Pulses are lacking in what aa? ANSWER- Methionine (or cysteine)

Eggs and chicken are lacking in what aa? ANSWER- none

Phenylketonuria is a deficiency in which enzyme and limits conversion of which two

amino acids? ANSWER- Phenylalanine hydroxylase; cannot convert phenylalanine to

tyrosine

Tyrosine is the precursor for what neurotransmitters? ANSWER- L-dopa --> dopamine --

> norepinephrine --> epinephrine (catecholamines)

Tyrosine is a precursor for what pigment? ANSWER- L-dopa --> melanin (skin

pigmentation)

Albinism is a problem with the conversion of what? ANSWER- L-dopa --> melanin

What hormones can tyrosine be converted to? ANSWER- T3, T4

What is melatonin derived from? ANSWER- Tryptophan --> serotonin --> melatonin

What is histamine derived from? ANSWER- Histidine

What is nicotinamide derived from? ANSWER- Tryptophan --> niacin --> nicotinamide

For every 10 kg of body wt, how many grams of protein does a person need?

ANSWER- 8g