Part 2 - lecture 1 - Quiz Flashcards
(57 cards)
Which sugar can act non-enzymattically to make modifications?
Glucose
Why must glucose always be at a certain concentration in our blood?
Anaerobic and brain cells require glucose for energy and without them they would be damaged
What do sugars interact with and how?
proteins, lipids, glycoproteins, glycolipids, proteoglycans, themselves - enzymatic reactions - they are chemically reactive
What are the dietary polysaccharides?
Glycogen (amylose and amylopectine) and starch (glycoproteins and proteoglycans)
What are the dietary dissacharides?
Sucrose and lactose
What makes up lactose?
Glucose and galactose
What makes up sucrose?
Glucose and fructose
What are indigestable carbs?
Carbs with unusual linkages, cellulose and fiber
What is glucose stored as?
Glycogen
Where is alpha amylase found and what does it do?
Mouth and pancreas to small intestine to digest larger polyglucoses like starch and glycogen
What cannot be digested by alpha amylase?
Lactose and sucrose
What happens in the small intestine?
Uses enzymes on mucsal cells to break down starch and glycogen into maltose and isomaltose - receives the disaccharides
What happens to monosaccharides?
They are absorbed by mucosal cells on epithelium
What happens if you are lactose or sucrose intolerance?
No enzyme on mucosal cells to break down so go to large intestine where bacteria have the enzyme to digest but produces a lot of gas and large intestine reacts to foreign substance by bloating, diarrhea, dehydration
How can lactose intolerance be tested?
Hydrogen breath test because gases like H2 are produced along with CO2 and carbon metabolites
What does SGLT-1 do?
Sodium glucose transport system - Active symporter of enterocytes that uses 2 sodium ions to move glucose and galactose from luminal side into cytosol
What is needed to counteract effects of SGLT-1
Sodium potassium ATPase on capillary side to push sodium out to protect membrane potential
What is GLUT-5?
Facilitated transporter of enterocytes specific to fructose to move inside cytosol
What is GLUT-2?
Facilitate transporter to move all monosaccharides (Glc, Gal, Fru) out of cytosol and into blood stream (on capillary side)
What is the function of glycolysis?
Sets stage for aerobic oxidation of carbs, supplies intermediates for carbohydrate storage and pentose phosphate pathway, can take up glycerol for triglyceride storage and degredation and can take up other monosaccharides
Where does glycolysis occur?
Cytosol - aerobic goes to mitochondria
What are some cell types that use anaerobic pathways because they lack mitochondria or have limited blood supply?
RBCs, cell of the eye like cornea, lens, retina, testis, leukocytes, white muscle fibers, kidney medulla
What are some aerobic cell types with lots of oxygen and mitochondria?
Brain, skeletal and heart muscle
What are the 3 stages of glycolysis?
Priming (energy investment), splitting stage, and oxidoreduction-phosphorylation stage (energy gaining)
