Protein Structure and Function Flashcards
Covalent bonds
Join building blocks into macromolecules like DNA.
Non-covalent bonds
Stabilize macromolecule shapes crucial for cellular life.
Macromolecules
Large biological molecules like proteins and nucleic acids.
Dehydration reactions
Join monomers by removing water, forming polymers.
ATP
Energy currency of the cell, vital for metabolism.
Redox reactions
Chemical reactions involving electron transfer, essential for life.
Amino acids
Building blocks of proteins, linked by peptide bonds.
Peptide bonds
Link amino acids, formed by dehydration reactions.
Protein structure levels
Include primary, secondary, tertiary, and quaternary structures.
Globular proteins
Compact proteins, often soluble, with diverse functions.
Fibrous proteins
Structural proteins, elongated and insoluble in water.
Protein misfolding
Incorrect folding can lead to diseases like Alzheimer’s.
Protein-protein interactions
Crucial for biological processes and cellular functions.
N-terminal
Free amino end of a polypeptide chain.
C-terminal
Free carboxyl end of a polypeptide chain.
Zwitterions
Amino acids at physiological pH with no net charge.
Chirality
Property of amino acids, except glycine, having two forms.
Hydrophobic amino acids
Tend to be inside globular proteins, avoiding water.
Hydrophilic amino acids
Able to form hydrogen bonds, found on protein surfaces.
Disulfide bonds
Covalent bonds formed between cysteine residues.
Secondary structure
3D structure formed by hydrogen bonds in polypeptides.
Alpha helix
Tightly coiled structure with R groups projecting outward.
Beta sheets
Formed by adjacent strands linked by hydrogen bonds.
Random coil
Irregular arrangement of polypeptide chains.
Motifs
Specific arrangements of secondary structure elements.
Leucine zipper
Example of an alpha helical protein involved in gene regulation.
Fibroin
Silk protein with antiparallel beta sheet structure.
Hydrogen bonding
Interactions stabilizing secondary protein structures.
Tertiary structure
Overall 3D arrangement of protein atoms.
Native fold
Specific conformation enabling biological function.
Cystine
Dimer of cysteine linked by disulfide bond.
Insulin
Hormone stored as inactive hexamer, active as monomer.
Protein domains
Independently stable structural motifs in proteins.
Kinase domain
Common protein domain involved in phosphorylation.
Quaternary structure
Association of multiple polypeptide chains.
Homo-multimers
Complexes of identical polypeptide chains.
Hetero-multimers
Complexes of different polypeptide chains.
Primary structure
Linear sequence of amino acids in a protein.
Protein diversity
Variety of protein structures reflecting function.
α-Keratin
Coiled-coil fibrous protein providing structural support.
Membrane proteins
Proteins interacting with lipid bilayers.
G-protein-coupled receptors (GPCRs)
Large family of membrane proteins with seven domains.
Ligand
Small molecule that binds to a protein.
Induced fit model
Conformational change upon ligand binding.
Enzymes
Proteins that catalyze biochemical reactions.
Active site
Region where substrate binds on an enzyme.
Transition state
Intermediate state during a chemical reaction.
Inhibitors
Molecules that decrease enzyme activity.
Peptidoglycan
Structural component of bacterial cell walls.
Penicillin
Antibiotic that irreversibly inhibits transpeptidase.
Neurodegenerative diseases
Diseases linked to protein misfolding and aggregation.
Lewy bodies
Intraneuronal aggregates associated with Parkinson’s disease.
Alpha-synuclein
Protein linked to Lewy bodies in Parkinson’s.
