Biochemistry: enzymes & glucose Flashcards
what is the function of an enzyme
increase the speed to equilibrium (not position) by reducing activation energy
what molecules are enzymes
usually proteins, rarely ribosomes
what does enzyme activity often depend on
co-factors and co-enzymes
what is a co-factor and its function
a metal ion(inorganic), involved in redox reactions to stabilise transition state
what is a co-enzyme, its function and give an example of a common co-enzyme
organic molecule
transiently alter charge/structure of enzyme, regenerated afterwards
common co-enzyme = NAD+
what are the 2 different ways an enzyme can bind
lock and key, OR induced fit model
what is an apoenzyme
an inactive enzyme form that requires a co-enzyme to become active and perform its function
what is a holoenzyme
the active compound formed by the combo of an apoenzyme and coenzyme
what is an isozyme
any of several forms of an enzyme that all catalyse same reaction but may differ in properties such as reaction rate
what is a zymogen
an inactive precursor that is converted into an active enzyme by action of an acid or other enzyme
what are the different forms of glucose storage
starch, glycogen, sucrose or converted into lipids
other than storage what else is glucose used for (3)
oxidised(pentose phosphate pathway) to ribose-5-phosphate, a precursor for nucleotide synthesis + DNA repair
fermented by anaerobic glycolysis to lactic acid
oxidised(aerobic glycolysis) to pyruvate
how does glucose enter cells
via Na+/Glucose symporters
eg GLUT 1 in brain
