Lec 3 Post-Translational Modifications

These flashcards cover key concepts related to post-translational modifications and cellular processes discussed in the lecture notes.

Prokaryotic Cell

A type of cell characterized by the absence of a true nucleus and membrane-bound organelles; typically 0.1-10 μm in size.

Eukaryotic Cell

A cell with a nucleus and membrane-bound organelles; usually larger than prokaryotic cells, measuring 10-100 μm.

Transcription

The process of converting DNA into RNA, leading to protein synthesis.

Post-Translational Modification (PTM)

Chemical modifications that occur to proteins after translation, impacting their function and stability.

Phosphorylation

The addition of a phosphate group to an amino acid residue in a protein, which can activate or deactivate the protein's function.

Ubiquitination

The process of adding ubiquitin to a protein, marking it for degradation or altering its function.

Glycosylation

The addition of carbohydrate moieties to proteins, resulting in glycoproteins that play critical roles in biological processes.

SUMOylation

The attachment of small ubiquitin-like modifiers (SUMOs) to proteins, affecting their stability and function.

Methylation

The addition of methyl groups to amino acid residues, which can regulate protein function and interactions.

Citrullination

The conversion of arginine residues in proteins to citrulline, which can affect protein folding and interactions.

Dephosphorylation

The removal of phosphate groups from proteins, generally reversing the effects of phosphorylation.

Kinases

Enzymes that catalyze the addition of phosphate groups to proteins during phosphorylation.

Phosphatases

Enzymes that remove phosphate groups from proteins, mediating dephosphorylation.

Cleavage of Amino Acid Chains

The process of cutting protein chains at specific locations, which is a type of post-translational modification.

Protein Stability

The ability of a protein to maintain its structure and function over time, influenced by post-translational modifications.

Histone Regulation

The process of modifying histone proteins, which affects DNA packaging and gene expression.

Extracellular Signaling

Communication between cells involving signaling molecules that can be influenced by post-translational modifications.

Signal Transduction

The process by which a cell converts an extracellular signal into a functional response, often mediated by PTMs.

Proteasome

A protein complex responsible for degrading ubiquitinated proteins, thus regulating protein levels within the cell.

Redox Modifications

Chemical modifications involving the gain or loss of electrons, which can alter protein function.