Biochemistry Quiz on Amino Acids and Enzymes

True (A)

6.7

<p>L-amino acid decarboxylase</p> Signup and view all the answers

<p>Bananas (B)</p> Signup and view all the answers

<p>Tyramine = Tyrosine Histamine = Histidine Putrescine = Arginine Phenylethylamine = Phenylalanine</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Gram-negative bacteria</p> Signup and view all the answers

<p>Glycine (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Limiting amino acid</p> Signup and view all the answers

<p>hydrophobic</p> Signup and view all the answers

<p>Serine = Forms sulfydryl bridges Threonine = Forms hydrogen bonds Cysteine = Forms hydrogen bonds Glutamate = Enhances taste and suppresses undesirable flavors</p> Signup and view all the answers

<p>Cysteine (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Gelatin</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>side chain</p> Signup and view all the answers

<p>Albumins (B)</p> Signup and view all the answers

<p>Casein</p> Signup and view all the answers

<p>Albumins = Soluble in water Globulins = Soluble in neutral salt solutions Glutelins = Soluble in dilute acid or alkali Prolamins = Soluble in 70% alcohol</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Glycoproteins (D)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Lysine, Tyrosine, Tryptophan (B)</p> Signup and view all the answers

<p>Peptides are short chains of amino acids.</p> Signup and view all the answers

<p>Nitrosamines are considered carcinogenic, meaning they can potentially increase the risk of cancer.</p> Signup and view all the answers

<p>sodium nitrite</p> Signup and view all the answers

<p>Lysine = α-aminoadipic acid Tyrosine = Dityrosine, Kynurenine Tryptophan = Kynurenic acid</p> Signup and view all the answers

<p>Proline, Tryptophan, Tyrosine (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Low pH (acidic environment) and high temperatures (e.g., frying, roasting) promote nitrosamine formation.</p> Signup and view all the answers

<p>β-turns (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Hydrophobic interactions</p> Signup and view all the answers

<p>Cold temperatures (C)</p> Signup and view all the answers

<p>tertiary</p> Signup and view all the answers

<p>All of the above (D)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Hydrogen bonds = Stabilize secondary structure Hydrophobic interactions = Drive protein folding Disulfide bonds = Form between two cysteine residues Ionic interactions = Occur between positively and negatively charged side chains</p> Signup and view all the answers

<p>Alpha-helices and beta-pleated sheets</p> Signup and view all the answers

<p>foaming</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Secondary structure denaturation = Loss of alpha-helices and beta-pleated sheets Tertiary structure denaturation = Disruption of covalent interactions like disulfide bonds Quaternary structure denaturation = Dissociation of protein sub-units Overall protein denaturation = Loss of solubility and activity</p> Signup and view all the answers

<p>Hydrogen bonds</p> Signup and view all the answers

<p>It is reversible when the denaturant is removed, except for egg white. (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>They are dissociated.</p> Signup and view all the answers

Nine amino acids that human bodies cannot synthesize and must be obtained through diet.

The essential amino acid present in the lowest quantity in a protein source compared to a reference protein.

A measure of the effectiveness of protein in supporting growth and maintenance based on essential amino acid content.

Characteristics of amino acids that affect the structure and function of proteins.

Amino acid side chains that are hydrophobic and restrict flexibility in peptide chains.

Weak bonds that form between polar side chains, aiding protein structure stability.

The ability of certain amino acids like L-glutamate to modify or suppress flavors in foods.

The activity of L-glutamate in modulating taste is stronger at lower pH levels.

The process where tyrosine is oxidized to DOPA by the enzyme tyrosinase in the presence of oxygen.

An enzyme that catalyzes the oxidation of tyrosine, requiring copper as a co-factor.

A process where fruits or vegetables turn brown due to enzymatic oxidation, mainly involving tyrosinase.

Essential mineral needed for the activity of tyrosinase in the oxidation process of tyrosine.

A chemical reaction that removes a carboxyl group from amino acids, forming biogenic amines.

Compounds formed from amino acids through decarboxylation, like tyramine and histamine.

A biogenic amine derived from tyrosine, associated with dietary sources and some poisoning risk.

A biogenic amine derived from histidine, related to allergic reactions and inflammatory responses.

Chemical reaction where amino acids lose electrons, often impacting protein function and health.

Carcinogenic compounds formed when nitrites react with amines in low pH environments.

The ability of proteins to perform their biological roles, affected by oxidation.

Used in cured meats for preservation but can lead to harmful nitrosamine formation.

Functional groups in amino acids that can donate or accept protons, affecting reactivity.

The process whereby nitrosamines become cancer-causing after metabolic activation in the body.

The core atom in amino acids bonded to four groups: hydrogen, amino, carboxyl, and side chain (R).

Proteins that yield amino acids upon hydrolysis like albumins and globulins.

A type of simple protein soluble in water, found in egg and serum.

Proteins that consist of amino acids combined with non-protein constituents.

Conjugated proteins with phosphate groups, such as casein in milk.

Proteins obtained from chemical or enzymatic methods, including derivatives like peptides.

Short chains of amino acids formed from the breakdown of proteins.

A type of secondary protein structure characterized by parallel or antiparallel strands linked by hydrogen bonds.

Polypeptide turns that allow a protein chain to reverse direction by 180 degrees.

The three-dimensional shape formed by the further folding of a polypeptide chain with secondary structures.

Arrangement of multiple polypeptide chains into a functional protein unit.

Forces that drive protein folding by promoting interactions between nonpolar amino acid side chains.

Covalent bonds formed between the sulfur atoms of two cysteine residues, important for protein stability.

The ability of a protein to maintain its structure under physiological conditions, influenced by interactions like hydrophobic forces.

Changes in protein structures without breaking peptide bonds.

Factors that can cause proteins to denature include acids, heat, and radiation.

Denaturation is often reversible if aggregated conditions are not present.

Denaturation can lead to loss of protein solubility in solution.

Denaturation can increase the intrinsic viscosity of proteins.

Denaturation disrupts regular patterns like α-helices and β-pleated sheets.

Denaturation disrupts covalent and non-covalent interactions without breaking peptide bonds.

Physical and chemical properties that affect proteins in food systems during various stages.