Bioengineering and biomedical engineering merge the disciplines of engineering, biology, and medicine to create techniques and devices that are based on an understanding of living systems and serve the objective of improving the quality of human and animal life.
Weight of 1 US Gallon of water = approx. 8.35 lb (about 3.785 kg). Weight of 1 Imperial gallon (i.e. UK measure) of water weighs 10 pounds (4.536 kg) by definition, at a specified temperature and pressure.
1 So a gallon of salt water weighs 8.556 lbs.  That's a common expression. A pint is 16 fluid ounces and 16 fluid ounces of water weighs approximately 16 dry ounces. Two pints to the quart, four quarts to the gallon means eight pints to the gallon, so a gallon weighs about eight pounds. But that only applies to FRESH water. Salt water has a whole range, depending on how much salt is dissolved in the water. So you'd have to add the weight of the dissolved salt.