Chap 8: Carbohydrates 2 Flashcards
Glycogenolysis Defined
the breakdown of glycogen
Regulation of Glycogenesis and Glycogenolysis
PKA is the main regulator of both
Glycogen synthase and glycogen phosphorylase work in
Opposition
Phosphorylation determines whether the enzyme
Active or inactive
Regulation of Glycogen Synthesis
Pathway that phosphorylate glycogen synthase will inactivate it
Regulation of Glycogen Breakdown
Glycogen phosphorylase is activated by phosphorylation and deactivated by dephosphorylation
Pentose Phosphate Pathway
+ Produces monosaccharides, NADPH and antioxidants
(Two phases: Oxidative and nonoxidative)
Regulation of the Pentose Phosphate Pathway
Glucose-6-phosphate dehydrogenase is regulated by levels of NADP+
Glutathione and the Pentose Phosphate Pathway
Glutathione is a tripeptide antioxidant that neutralizes reactive oxygen species
Glycoproteins Defined
Glycoproteins are membrane-bound or extracellular proteins with some amount of carbohydrate modification
(carbs and protein)
Glycolipids Defined
Glycolipids are membrane phospholipids with an attached carbohydrate moiety exposed to the external environment
(carbs and lipids)
Examples of Glycolipids
+Lipopolysaccharides
+Glycosylphophatidylinositol (GPI)
+Cerebrosides
+Gangliosides
Proteoglycans Defined
Proteoglycans are extensive mesh nets of polysaccharides joined to fibrous proteins
Peptidoglycans Defined
Peptidoglycans are lengthy chains of polysaccharides cross-linked by peptides and found in bacterial cell walls
Extracellular Matrix Defined
Extracellular matrix is a tissue made of proteins, glycoproteins, and proteoglycans in a fibrous, gel-like mesh
Collagen Synthesis requires
Vitamin C
(Proline hydroxylation is key to this process
Elastin is
Responsible for the core of elastic fibers found in skin and arteries
Fibronectin
Found in the extracellular matrix in a soluble form in the circulation
Cell Culture Defined
Cell culture is a process in which cells are grown on a plastic tissue culture for researchers to study cells under different conditions
What is glycogen
A stored form of glucose
Glycogenesis Defined
Glycogenesis is the synthesis of glycogen
Components important for glycogenolysis
Glycogen phosphorylase &
Glycogen Debranching enzyme
Phosphorylation determines
whether the enzyme is active or not
Glycogen synthase works opposite to
Glycogen phosphorylase
Epimers
type of isomer that differ only in the stereochemistry about a single chiral center
Glucose-6-phosphate dehydrogenase is regulated by
Levels of NADP+
Glutathione is a tripeptide antioxidant that neutralizes
reactive oxygen species
Peptidoglycans Defined
Peptidoglycans are lengthy chains of polysaccharides cross-linked by peptides and found in bacterial cell walls
