Prelim-Physio Intro

• Most abundant in cells; the principal fluid medium in the cell present in most cells except for fat cells

  water
• most abundant in cells next to water

  proteins
• soluble in fat solvents, insoluble in water

  lipids
• principally for cell nutrition dissolved glucose is present in the extracellular fluid and readily available for the cell


  carbohydrates
• function of carbohydrates

  Many have a negative electrical charge

  glycocalyx of some cells attaches to the glycocalyx of other cells

  Many of the carbohydrates act as receptor substances for binding hormones
• PHOSPHOLIPIDS has hydrophilic head - phosphate end, soluble in water has hydrophobic tail - fatty acid end, soluble in fats impermeable to water soluble substances (ion, glucose, urea) permeable to fat soluble substances (oxygen, carbo dioxide, alcohol
• aids in signal transmission

  SPHINGOLIPIDS
• controls fluidity of the membrane

  cholesterol
• sugar + nitrogenous base

  NUCLEOSIDES
• large immature single strand RNA

  PRECURSOR MESSENGER RNA (pre-mRNA)
• directs splicing

  SMALL NUCLEAR RNA
• carries genetic code to cytoplasm

  MESSENGER RNA
• forms ribosomes

  RIBOSOMAL RNA
• transports amino acids to the ribosomes to be used in assembly of proteins

  TRANSFER RNA
• regulate gene transcription and translation

  MICRO RNA