ch. 17: carbohydrate digestion (review?)

what linkages does salivary amylase break

alpha 1,4 linkages (breaks down starch, not fiber)

what animals have salivary amylase

men, apes, pigs, rats, some avian

what animals do NOT have salivary amylase

dogs, cats, cattle, horses

what does pancreatic amylase do to starches?

hydrolyzes alpha 1,4 linkages and alpha 1,6 linkages

amylose → maltose

amylopectin → maltose + isomaltose (dextrin)

what does amylase hydrolysis of starch results in (4 things)

1) starch

2) maltose

3) isomaltose (dextrin)

4) glucose

what CHO’s are NOT hydrolyzed by amylase

1) cellulose

2) hemicellulose

3) lactose

4) sucrose

5) maltose

what enzymes are released by the duodenum for starch digestion

lactase, sucrase, maltase and isomaltase

what do lactose, sucrose, maltose, and isomaltose get broken down into by their respective enzymes?

1) lactose —lactase—> galactose + glucose

2) sucrose —sucrase—> fructose + glucose

3) maltose —maltase—> glucose + glucose

4) isomaltose —isomaltase—> glucose + glucose

what are the residues of digestion that enter the cecum and colon

crude fiber and undigested NFE

what does the fermentation of CHOs in the large intestine produce

VFAs

rank galactose and glucose in their rate of absorption with active transport

galactose »» glucose

(young animals need energy from milk quickly)

rank the following in their rate of absorption with passive diffusion: xylose, mannose, arabinose, fructose

fructose » mannose » xylose » arabinose

what are the relative concentrations of glucose and Na in the cytoplasm (high or low)

1) glucose = high concentration

2) Na = low concentration (pumped out to be used to bring glucose in)

how are starch and cellulose digested in the RUMEN

by microbial amylase and microbial cellulase respectively

converted into glucose

how is glucose broken down into the rumen

glucose —MCO—> 2 acetic acids (VFAs) + CO2 + CH4

how are CHOs digested in the hindgut of a ruminant

similarly to rumen

undigested CHO and NFE —MCO amylase and MCO cellulase—> glucose —MCO—> VFAs

what is lactose intolerance

1) genetic correlation where you lack lactase

2) results in accumulation of gas & diarrhea

what is diabetes mellitus

1) lack of insulin leads to cells not being able to absorb glucose

2) blood glucose levels increase and spill over into the urine