Biochemistry: Protein Structure and Function

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

<p>Breakdown into amino acids (C)</p> Signup and view all the answers

<p>Catalysis of biochemical reactions (A)</p> Signup and view all the answers

<p>Oxidative deamination (C)</p> Signup and view all the answers

<p>Denaturation disrupts proteins' 3D structures without breaking peptide bonds. (D)</p> Signup and view all the answers

<p>They serve as the primary macromolecule accounting for 15% of total cell mass. (A)</p> Signup and view all the answers

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

<p>Proteins could not be broken down into amino acids. (C)</p> Signup and view all the answers

<p>Only 20 amino acids. (A)</p> Signup and view all the answers

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

<p>They consist of unbranched polymer chains of amino acids. (D)</p> Signup and view all the answers

<p>50% (A)</p> Signup and view all the answers

<p>Jacob Berzelius in 1839 (C)</p> Signup and view all the answers

<p>Acidic solution (C)</p> Signup and view all the answers

<p>It has both positive and negative charges but overall is neutral. (D)</p> Signup and view all the answers

<p>It switches from zwitterion to negatively charged form. (A)</p> Signup and view all the answers

<p>They help transition amino acids to their negative ion form. (B)</p> Signup and view all the answers

<p>Negatively charged form (A)</p> Signup and view all the answers

<p>H3N+ - C - COO- (C)</p> Signup and view all the answers

<p>A specific amino acid's side chain that varies among different amino acids. (D)</p> Signup and view all the answers

<p>H3N+ – C – COOH (C)</p> Signup and view all the answers

<p>2.95 (D)</p> Signup and view all the answers

<p>It is the pH at which the amino acid has no net charge. (B)</p> Signup and view all the answers

<p>Using the sum of pKa1 and pKa2 divided by 2. (B)</p> Signup and view all the answers

<p>It predominates over the zwitterion form. (B)</p> Signup and view all the answers

<p>To control the charge state of the amino acids. (D)</p> Signup and view all the answers

<p>Their charge at specific pH levels. (D)</p> Signup and view all the answers

<p>2.09 and 3.86 (C)</p> Signup and view all the answers

<p>The concentrations of its intermediate form and negative ion are equal. (C)</p> Signup and view all the answers

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

<p>They are often derived from vitamins. (C)</p> Signup and view all the answers

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

<p>It denotes that the molecule acts as an enzyme. (D)</p> Signup and view all the answers

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

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

<p>They catalyze the transfer of a group of atoms. (D)</p> Signup and view all the answers

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

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

<p>They exist as zwitterions. (A)</p> Signup and view all the answers

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

<p>It produces a violet coloration if amino acids are present. (D)</p> Signup and view all the answers

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

<p>Negative ion form (D)</p> Signup and view all the answers

<p>Alanine and isoleucine do not migrate, while aspartic acid and arginine do. (D)</p> Signup and view all the answers

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

Categorizing amino acids based on functional groups and polarity.

Amino acids can act as both acids and bases due to their amino and carboxyl groups.

Connecting amino acids through peptide bonds to form peptides.

Determining the order of amino acids in a peptide.

Some small peptides have crucial biological roles.

Proteins have different organizational levels, influenced by amino acid sequence.

The protein's structure dictates its function.

Hydrolysis breaks down proteins into their constituent amino acids, while denaturation disrupts the protein's structure without breaking bonds.

Proteins are naturally occurring unbranched polymers of amino acids connected by peptide bonds.

An amino acid contains both a carboxyl (-COOH) group and an amino (-NH2) group.

The 20 amino acids found in humans.

Proteins are crucial for various physiological functions in the body.

Proteins account for 15% of total cell mass and almost 50% of its dry weight.

The bond that connects amino acids in a protein.

Early scientists thought whole proteins were incorporated directly into tissues, neglecting the existence of smaller units (amino acids).

Early nutrition studies recognized the importance of nitrogen-containing compounds for animal survival.

The pH at which an amino acid predominantly exists in its zwitterion form.

The electrically neutral form of an amino acid, where the amino group is protonated (+) and the carboxyl group is deprotonated (-).

The dipolar ion form of an amino acid, with both a positive and negative charge.

The process of an amino acid gaining or losing protons (H+) to form different charged species.

The balance between the zwitterion, positive ion, and negative ion forms of an amino acid in solution; the dominant species changes with pH.

The pH at which an ionizable group of an amino acid exists in two forms with equal concentrations.

The isoelectric point can be calculated using the formula: pI = (pKa1 + pKa2) / 2.

The form of an amino acid with a net positive charge under acidic conditions.

A method for separating charged molecules (like amino acids) in an electric field using paper as a matrix.

The form of an amino acid with a net negative charge under basic conditions.

The pH of the solution determines which form (zwitterion, positive ion, or negative ion) of an amino acid is most prevalent.

Techniques like electrophoresis are used to isolate and analyze amino acids by their charge and size.

A medium, like paper or gel, that holds the sample during separation by electrophoresis.

An example of how varying pH causes changes in the ionization state of an amino acid (alanine).

The side chain of an amino acid, which remains unchanged in solution under varying pH conditions, unless otherwise noted, in the context of ionization.

The isoelectric point of aspartic acid is approximately 2.95.

A technique that separates molecules based on their charge and size by applying an electric field, causing them to migrate towards oppositely charged electrodes.

The positively charged electrode in electrophoresis, attracting negatively charged molecules.

The negatively charged electrode in electrophoresis, attracting positively charged molecules.

The isoelectric point, the pH at which an amino acid exists as a zwitterion and has no net charge.

At a specific pH, amino acids will migrate towards either the anode or cathode depending on their overall charge, determined by their pI.

At pH 6, amino acids with pI below 6 will migrate towards the anode (negative), those with pI above 6 will migrate towards the cathode (positive), and those with pI near 6 will remain stationary.

After electrophoresis, ninhydrin solution is sprayed onto the matrix to reveal the locations of amino acids by creating a violet coloration where they are present.

An enzyme without its cofactor. This inactive form requires a cofactor to become fully functional.

A complete, catalytically active enzyme. It consists of an apoenzyme combined with its cofactor.

A non-protein molecule that assists an enzyme in its catalytic activity.

A small organic molecule that acts as a cofactor. Many coenzymes originate from vitamins.

A tightly bound coenzyme that remains permanently attached to the enzyme.

An enzyme that catalyzes oxidation-reduction reactions.

An enzyme that catalyzes the transfer of a functional group between molecules.

An enzyme that catalyzes the hydrolysis of a molecule, breaking it down using water.