Intro to carbs (1) Flashcards
In a D sugar, how would you distinguish an alpha anomer or beta anomer?
alpha - OH is opposite to CH2OH
–starts down
Beta - OH is in same direction as CH2OH
-starts up
What is:
- disaccharide
- oligosaccharide
- polysaccharide
- 2 sugars covalently bound
- 2-15 sugars covalently bound
- many sugars covalently bound
What is amylose?
a starch with alpha 1,4 linkages
What is amylopectin?
a startch wtih alpha 1,4 linkages
alpha 1,6 branches
What is lactose?
galactose bound to glucose
B 1,4 linkages
What is sucrose?
alpha 1,2 glucose to fructose
(hexagonal cyclic structure = fructose)
-table sugar
-non-reducing sugar because OH’s of two anomeric Cs are not free
What is the structure of glycogen?
identical to amylopectin, but has a bit more branching
Define:
- endoglycosidases
- exoglycosidases
- disacharidases
- cleaves internal glycosidic bonds
- cleaves terminal glycosidic bonds
- cleaves glycosidic bonds in disaccharides
What is alpha-amylase?
cleaves Glu-alpha 1,4-Glu
-endoglycosidase
What is glucoamylase?
cleaves Glu-alpha 1,4-Glu
-exoglycosidase
What is maltase?
cleaves Glu-alpha 1,4- Glu
-disacharidase (and some larger)
What is isomaltase?
cleaves Glu-alpha 1,6-Glu
-disacharidase (and some larger)
What is lactase?
cleaves Gal-B1,4-Glu
-disacharidase
What is sucrase?
cleaves Glu-alpha 1,2 -Fru
-disaccharidase
What is cellulose?
linear polysaccharide
starch with B1,4 linkages
-CANT be digested by humans
What is the function of salivary amylase?
cleaves starch polymers into smaller polysacharides
-inactivated by acid in the stomach
What is the function of pancreatic alpha-amylase? What products does it produce?
continues hydrolyzing starch digestion Produces: -maltose -maltotriose -longer linear oligosacccharides -alpha-dextrins -isomaltose
Where does the digestion of oligos and disaccs to monos take place?
glycosidases that are attached to the brush border
in the jejunum
What are the glycosidases at the brush border? (5)
- glucoamylase
- maltase
- isomaltase
- sucrase
- lactase
What does the severity of lactase intolerance symptoms depend on?
ethnicity, age, speed of digestion
Glucose is the exclusive fuel of:
RBCs
What is the function of glycolysis?
produce pyruvate and ATP
- in all cells
- cells with mitochondria and O2–> combo with CAC
Where does the conversion of glucose into glycogen take place?
liver and muscle
What is the function of the pentose phosphate pathway?
generates NADPH
-critical for making fatty acids
What is “breakdown of glycogen to glucose”
glycogenolysis
What is” synthesis of glucose from non-carb sources such as AAs”
gluconeogenesis
What are the three effects of glucagon release ?
mobilize fuels to inc blood glucose
- inc glycogen breakdown in liver
- inc gluconeogenesis in liver
- inc lipolysis in adipose tissue
What are the three functions of insulin?
promotes fuel storage:
- increases glycogen synthesis in liver & muscle
- inc fatty acid synthesis in the liver
- inc triglyceride synthesis