biochemistry-biology summary.ALT123

Glycolysis



Pyruvate is the end product of glycolysis


In aerobic glycolysis, oxygen is needed to reoxidize NADH produced during oxidation of
glyceraldehyde-3-phosphate


Aerobic glycolysis allows for the conversion of pyruvate into acetyl CoA



In anaerobic glycolysis, pyruvate is reduced to lactate as NADH is oxidized into NAD+ ,
and happens in cells that lack mitochondria



Glucose cannot diffuse into cells, so needs transportation via sodium-independent
facilitated diffusion transport system, or ATP-dependent sodium-monosaccharide
cotransport system



Sodium-independent:



GLUT 1-14



Exist in two conformations, change conformation upon binding to glucose to allow
entrance of glucose




Different glucose receptors:



GLUT 1: BBB
 BLOOD (RBCs)

,  Fetus

 Blood brain barrier

 Low in adult muscle


GLUT 2: KIDS LIPS

 Kidneys

 Liver

 Beta cells of pancreas

 Can uptake glucose in case of high glucose levels, or export glucose in case of
low blood glucose levels; other GLUTs can only import glucose



GLUT 3: PINK

 Placenta

 Neurons
 Kidney



GLUT 4: MOTHER FATHER

 Muscle

 Fat

 Insulin increase number of this transporter


Facilitated diffusion is uptake of glucose down a concentration gradient (from high level
to low level) therefore not needing energy


GLUT 5 transports fructose in small intestine and testes