Ch 1 Biochemistry Flashcards
Isotope
atom of one element that have same chemical formula, but different number of neutrons. some are radioactive, known as radioisotopes
tracer
radioactive carbon can be used as a tracer, incorporated into molecules of carbon dioxide to track metabolic pathways
ionic bonds
form when electrons are transferred between anion and cation. Anions gain electrons, cations lose.
covalent bonds
form when atoms share electrons. results in a molecule
polar bonds
covalent bond with unbalanced forces. have stronger attractions.have negative and positive ends.
nonpolar bonds
covalent bonds with balanced forces. these attractions are weaker, like CO2. They are linear.
hydrophobic
repelled by water. lipids
hydrophilic
attracted to water. phosphate
characteristics of water
high specific heat, high heat of vaporization, adhesion properties, universal solvent, cohesion tension, and ice floats on water.
bicarbonate ion
most important buffer in human blood
buffer
substances that resist changes in pH. they absorb excess hydrogen ions ir donate hydrogen ions when too few.
Carbohydrates
made of carbon, hydrogen, and oxygen. supply quick energy, one gram releases 4 calories of heat when burned. made of monosaccharides, disaccharides, and polysaccharides.
monosaccharides
C6H12O6, glucose, galactose, and fructose. they are all isomers of each other.
disaccharides
two monos joined together by dehydration synthesis.
glucose + glucose =
maltose + water
glucose + galactose =
lactose + water
glucose + froctose =
sucrose + water
hydrolysis
opposite of dehydration synthesis; breakdown of compound with addition of water. occurs during digestion.