7.7 Metabolic Integration Flashcards
what happens to excess glucose in cells?
it can be stored in cells and then mobilized when necessary
what are the two major forms for glucose storage?
glycogen and starch
glycogen
the form in which glucose is stored in animals
starch
the form in which glucose is stored in plants
describe the structure of glycogen:
a large, branched chain of glucose molecules attached to a central protein.
describe the structure of starch:
a large, branched chain of glucose molecules found in plants,stored in granules inside cells
where can glycogen be stored?
the muscle (provides ATP for muscle contraction) or he liver (central glycogen storehouse)
glycogen provides a source of:
glucose-6-phosphate (cleaved as glucose 1-phosphate and then converted into glucose 6-phosphate which is an intermediate in glycolysis)
how many ATP molecules are produced from one glucose molecule cleaved from a glycogen chain?
3 (ATP consuming step 1 is bypassed)
how are disaccharides hydrolyzed?
they are converted into monosaccharides, generally glucose which directly enters glycolysis
how are monosaccharides other than glucose hydrolyzed?
they are converted into intermediates of glycolysis that come later in the pathway
in addition to carbohydrates, what is a good source of energy?
lipids (C-H bonds carry lots of chemical potential energy)
B-(beta)oxidation
the process of shortening fatty acids by a series of reactions that sequentially remove two carbon units from their ends
beta oxidation does not produce ATP, instead it…
releases a large number of NADH and FADH2 that provide electrons for the synthesis of ATP by oxidative phosphorylation
fatty acids are a useful and efficient source of energy but cannot:
be used by all tissues of the body (ex. brain and red blood cells depend on glucose for energy)
