U U (Uracil) U3 U5 U5-15kD UAS )Upstream Activating Sequence) Ubiquinol (QH2; Reduced Coenzyme Q) Ubiquinone (CoQ) Ubiquitin (Regulatory Protein) Ubiquitin Activating Enzyme Ubiquitin Conjugating Enzyme Ubiquitin Protein Ligase Ubiquitination Ubiquitous Ubiquitous Ubiquitylation UCSC Genome Browser UDG (Uracil-DNA Glycosylase) UDI )Uracil-DNA Glycosylase Inhibitor) UDP (Uridine 5-Diphosphate) UDP (Uridine Diphosphate) UDP-3-O-acyl-N-Acetylglucosamine Deacetylase (LpxC) UDPG (UDP-Glucose) UDPG (Uridine Diphosphate Glucose) UDP-Galactopyranose Mutase UDP-Galactose 4-Epimerase UDP-Glucuronate UFO (Unidentified Flying Object) UFO (Unidentified Flying Object) (2) Ufology UK Biobank (UKB) UK Biobank Cohort Ulcerative Colitis Ultimate Carcinogen Ultra- Ultra- Ultra Filtration Ultra High Temperature (URT) Sterilization Ultra Luminous X-rays Ultra Micro Analysis Ultra Microscope Ultra Microscopic Ultra Microtome Ultra Processed Foods (Ultraprocessed Food) Ultra Sonic Wave Ultra Structure Ultra Violet Irradiation Ultra Violet Mutation Ultra Violet Spectroscopy Ultracentrifuge Ultracentrifuge Ultracentrifuges Ultrafiltration Ultramicroanalysis Ultramicroscope Ultramicroscope (Dark Field Microscope) Ultrasonography (Echography) Ultrasound Ultrasound (Ultrasonic) Ultrasound (Ultrasonic) Ultrasound Examination Ultrasound Imaging (Sonography) Ultrasound Ultrasonics Ultrastructural Imaging Ultrastructure Ultrastructure Ultra-Targeted Therapies Ultraviolet (UV) Light Radiation Ultraviolet (UV) Spectrum Ultraviolet Irradiation Ultraviolet Microscope Ultraviolet Mutation Ultraviolet Spectroscopy Ultraviolet- Visible (UV-Vis) Spectroscopy Ultrmicrotome UlV Microscope (Ultraviolet Microscope) Umami Taste Receptors (Glutamate Taste Receptors) Umbilical Cord Umbrella Trial UMP (Uridin 5-Monophosphate, Uridine Monophosphate, Uridylic Acid) Unassayed Unbalanced Unbalanced Translocation Uncertainty Uncertainty Uncertainty of Measurement Uncertainty Principle UncertaintyPrincipal Uncoating Uncompetitive Inhibition Uncompetitive Inhibitors Uncompetitive Inhibitors (2) Uncoupler (Uncoupling Agent) Uncoupler (Uncoupling Agent) Uncoupler of Oxidative Phosphorylation Uncoupling Agent (Uncoupler) Uncoupling Proteins ((UCPs) Undecaprenyl Pyrophosphate Synthase Undecoylium Underwound Undulator Unequal Crossing Over (Nonreciprocal Recombination) Unexplained Infertility UNFCCC (United Nations Framework Convention on Climate Change) Unfolded Protein Response Ungulata Unhinged (Deranged) Uni- Unicellular Unidentified Anomalous Phenomena (UAP) Unidirectional Unidirectional Replication Unidirectional Replication Unified Atomic Mass Unit Uniform Uniform Distribution Unikonta Unilateral Unimodular Gravity Uninducible Union Uniparental Disomy Uniparental Disomy Uni-Parental Disomy Unipolar Uniport Unique Gene Unisexual Unit Unit Membrane Model United Nations Environment Programme Univalent Univalent Antibody Univalent Reduction Univalent Vaccine (Monovalent Vaccine) Universal Universal  Recipient (Blood) Universal Acceptor Universal Antidote Universal Code Universal Donor Universal Genetic Code Universal Indicator Universal Indicator Universal Recipient Universal Solvent Universe Universe Singularity Unpackaging Genes (Helicase Enzyme) Unsaturated Unsaturated Unsaturated Alcohol Unsaturated Compound Unsaturated Fat Unsaturated Fatty Acid Unsaturated Fatty Acids Unsaturated Fatty Acids Unstructured Data Unsupervised Learning Untranslated 5’ Region Ununoctium ;Uuo (Oganesson; Og) Unwinding Protein Unwinding Proteins UP Element Up Mutation Up Regulation/ Down Regulation UPF Proteins Upgrading Upregulation Upstream Upstream /Downstream Uracil (U) Uracil (U) Uracil Inhibitor Uracil-DNA Glycosylase Uranium (U) Uranium (U) Uranium 235 (Enriched Uranium) Uranium 238 Uranium Enrichment Uranium Enrichment (2) Uranium-235 (U-235) (2) Uranus Planet Urate Oxidase Urban Genetics Urban Heat Urbanization Urea Urea ((NH2)2CO) (3) Urea (CH₄N₂) (2) Urea Cycle Urea Cycle Urea Cycle (Ornithine Cycle) Urea Enzyme Urea Production Urea Transporter Urea, H2NCONH2 (ouronG = Urine) Urease Urease Accessory Protein Urease (Urea Enzyme) Ureotelic Ureotelic Ureotelic Animals Urethra Urethra (OureinG = to Urinate) URF )Unidentified Reading Frame) Uric Acid Uricolytic Enzyme Uridine Uridine 5'-Monophosphate Synthase Uridine Phosphorylase Urinary Tract Cancer Urination Urine Urine Color Urochrome Urokinase Urolithins Urothelium US Advanced Research Projects Agency—Energy (ARPA-E) US Health Insurance Portability and Accountability Act (HIPAA) US National Institutes of Health's Recombinant DNA Advisory Committee Usnea Usnea (2) Usnea Lichen (Beard Lichen) Usnic Acid Usnic Acid Uterine Utero- Uterus (Latin, for womb) Uterus Neck (Cervix) UTP (Uridine Triphosphate) Utrasonic Scanning UTRs (Untranslated Regions) UV (Ultraviolet) UV / Visible Spectrophotometry UV Absorbance at 280 nm UV Irradiation UV Irradiation UV Method Uveal Melanoma uvr (UV Repair) UvrABC