Introduction to Cell Biology & Biochemistry

These flashcards cover essential vocabulary from the lecture on cell biology and biochemistry, focusing on the properties and classifications of amino acids.

Amino Acids

Building blocks of proteins categorized by their side chains.

Zwitterion

A molecule with both positive and negative charges, resulting in a net charge of zero.

Hydrophobic Side Chains

Amino acids that are nonpolar and typically found in the interior of proteins.

Aliphatic R groups

Amino acids with R groups consisting only of carbon and hydrogen (C-C & C-H bonds) with no double bonds.

Aromatic R groups

Amino acids with side chains that contain aromatic rings, such as phenylalanine, tyrosine, and tryptophan.

Cystine

A dimer of cysteine formed through the oxidation of two cysteine residues, linked by a disulfide bond.

pKa

The pH at which a compound is 50% in its uncharged form and 50% in its charged form.

Basic Amino Acids

Amino acids that can accept protons, e.g., arginine, lysine, and histidine.

Acidic Amino Acids

Amino acids that donate protons and typically carry a negative charge at physiological pH.

Post-translational modifications

Chemical modifications of proteins after synthesis that can affect their function, such as phosphorylation or glycosylation.

UV Absorbance

A critical property of proteins and nucleic acids used in their isolation, with different maximum absorbances (280 nm for proteins, 260 nm for DNA).

Disulfide bond

A covalent bond formed between the sulfur atoms of two cysteine residues, important for stabilizing protein structure.