Fixation: Theory, Chemistry and Fixative Types
Fixation preserves tissue morphology by stabilizing proteins and preventing autolysis, with the choice of fixative determining downstream staining success.
BiologySpecimen Reception, Gross Examination and Dissection
Specimen reception and gross examination are the first steps in histopathological preparation, ensuring correct identification and representative sampling.
Biology
Amino Acid-Derived Molecules
Amino acids serve as precursors for a diverse range of biologically active molecules including neurotransmitters, hormones, porphyrins, melanin, and nitric oxide.
BiologyBranched-Chain Amino Acids
Branched-chain amino acids leucine, isoleucine, and valine are essential amino acids with unique metabolic pathways and important roles in muscle protein synthesis and energy metabolism.
BiologyG Protein-Coupled Receptors
G protein-coupled receptors are the largest family of cell surface receptors, transmitting signals from hormones, neurotransmitters, and sensory stimuli through heterotrimeric G proteins.
BiologyHormones and Their Classification
Hormones are chemical messengers secreted by endocrine glands that travel through the bloodstream to regulate the activity of distant target tissues.
BiologyJAK-STAT Signaling Pathway
The JAK-STAT signaling pathway transmits signals from cytokines, interferons, and growth factors to the nucleus, regulating gene expression in immune responses and cell growth.
BiologyReceptor Types and Mechanisms
Cellular receptors are proteins that bind signaling molecules and initiate intracellular responses, classified into four main types based on their structure and mechanism.
BiologyReceptor Tyrosine Kinases
Receptor tyrosine kinases are a class of enzyme-linked receptors that regulate cell growth, differentiation, metabolism, and survival through tyrosine phosphorylation.
BiologySecond Messengers
Second messengers are small intracellular signaling molecules that relay and amplify signals from cell surface receptors to intracellular targets.
BiologyWnt, Notch, and Hedgehog Signaling
Wnt, Notch, and Hedgehog are three highly conserved signaling pathways that control cell fate decisions, embryonic development, and tissue homeostasis.
BiologyApoptosis and Cell Death
Apoptosis is a programmed form of cell death that eliminates unwanted cells through a tightly regulated cascade of caspase activation.
Biology