Category: F

  • Fatty acid oxidation

    A process that occurs after the glycerides are hydrolyzed to glycerol and fatty acids. This oxidation is called p oxidation and occurs in the mitochondria. It is preceded by the transport of the fatty acid into the mitochondria via the acyl carnitine transport system. While most of the fatty acids that enter the p oxidation…

  • Fatty acid esterification

    The joining of a fatty acid to a carbon skeleton using oxygen. The resultant product is a monoglyceride, diglyceride, or triglyceride (triacylglyceride). Triacylglycerides are formed in a stepwise fashion. First, a fatty acid (usually a saturated fatty acid) is attached at carbon 1 of the glycerophosphate. The phosphate group at carbon 3 is electronegative and…

  • Fatty acid elongation

    The lengthening of fatty acids by the addition of two carbon units (acetyl groups). Elongation occurs in either the endoplasmic reticulum or the mitochondria. The reaction differs depending on where it occurs. In the endoplasmic reticulum, the reaction sequence is similar to that described for the cytosolic fatty acid synthase complex. The source of the…

  • Fatty acid desaturation

    The conversion of saturated fatty acids to unsaturated fatty acids in the body. Desaturation occurs in the endoplasmic reticulum and in the microsomes. The enzymes that catalyze desaturation are the Δ9, Δ6, or Δ3 desaturases. They are sometimes called mixed function oxidases because two substrates (fatty acid and nicotinamide adenine dinucleotide phosphate [NADPH]) are oxidized…

  • Fat substitutes

    Synthetic compounds designed to provide the food characteristics of fat without the energy value.  

  • Fasting blood glucose

    The level of glucose in the blood after 12-16 hours without food, usually between 80-120 mg/dL or 4-6 mmol/L. Levels below this range indicate hypoglycemia; levels above this range indicate hyperglycemia.  

  • Facilitated transport

    Transport against a concentration gradient using a carrier. Facilitated transport does not require energy or sodium.  

  • Fusional convergence

    Convergence induced by fusion stimuli without reflex as sociation with accommodation.  

  • Frothing

    The presence of myriads of tiny air bubbles underneath a contact lens, due to the fact that air has been trapped underneath the lens.  

  • Fluorescein pattern

    The dye pattern appearing underneath a contact lens when the tear fluid has been dyed with fluorescein and the eye is observed under ultraviolet light.