Introduction to Proteins, Carbohydrates, and Acids

Flashcards covering key concepts including amino acids, proteins, carbohydrates, acids, bases, and titration processes.

Amino Acid

A molecule consisting of an amine group (NH2), a carboxyl group (COOH), hydrogen, and an R group attached to a central carbon.

Zwitterion

A molecule that has both positive and negative charges simultaneously.

Isoelectric Point (pI)

The pH at which an amino acid has no net charge.

Denaturation

The loss of protein structure due to heat, pH changes, or chemicals.

The Biuret Test

A test that detects the presence of proteins (peptide bonds) and turns purple if positive.

Types of Carbohydrates

Monosaccharides, disaccharides, and polysaccharides.

Benedict’s Test

A test that detects reducing sugars, indicated by a color change from blue to green/yellow/orange/red.

Iodine Test

A test that detects starch, producing a blue-black color if positive.

Lipids

Hydrophobic (nonpolar) molecules such as fats, oils, and steroids.

Arrhenius Definition of an Acid

A substance that produces H+ ions in solution.

Arrhenius Definition of a Base

A substance that produces OH- ions in solution.

Brønsted–Lowry Acid

A proton donor.

Brønsted–Lowry Base

A proton acceptor.

Strong vs Weak Acids

Strong acids fully dissociate, while weak acids only partially dissociate.

pH Measurement

A measure of the concentration of hydrogen ions (H+).

Low pH

Indicates high acidity and high concentration of H+ ions.

High pH

Indicates basic conditions and low concentration of H+ ions.

Properties of Acids

Sour taste, react with metals, and turn litmus paper red.

Properties of Bases

Bitter taste, slippery feel, and turn litmus paper blue.

Titration Purpose

To determine the concentration of an unknown solution.

Equivalence Point in Titration

The point where moles of acid equal moles of base.

Titration Formula

MaVa = MbVb.

Endpoint of Titration

The point where the indicator changes color.

Buffer

A solution that resists changes in pH.

Amino Acids and Buffers

Amino acids can act as buffers due to their ability to gain or lose protons.