12. Breakdown of Food (nutrients, vitamins, minerals) Flashcards
(104 cards)
Digestion in the MOUTH:
MECHANICAL: Chewing/mastication & Swallowing
CHEMICAL: CARBOHYDRATES and FATS
Digestion/Absorption in the STOMACH:
MECHANICAL: PERISTALTIC MIXING and PROPULSION
CHEMICAL: PROTEINS & FATS
ABSORPTIN of LIPID-SOLUBLE SUBSTANCES ie Alcohol, Aspirin
Digestion/Absorption in the SMALL INTESTINE:
MECHANICAL: MIXING and propulsion, primarily SEGMENTATION
CHEMICAL: CARBOHYDRATES, FATS, POLYPEPTIDES, NUCLEIC ACIDS
ABSORPTION of PEPTIDES, AMINO ACIDS, GLUCOSE, FRUCTOSE, FATS, WATER, MINERALS, VITAMINS
Digestion/Absorption in the LARGE INTESTINE:
MECHANICAL: SEGMENTAL MIXING and propulsion
ABSORPTION of WATER*, IONS, MINERALS, VITAMINS, ORGANIC MOLECULES
(NO Chemical digestion)
what is there early ABSORPTION of in the STOMACH
LIPID SOLUBLE Substances
what is there CHEMICAL DIGESTION of in the MOUTH
CARBOHYDRATES
FATS
what is there CHEMICAL DIGESTION of in the STOMACH
PROTEINS
FATS
PROTEINS are BROKEN DOWN into AMINO ACIDS which are USED for
PROTEIN SYNTHESIS
& ENERGY PRODUCTION
COMPLEX CARBOHYDRATES are BROKEN DOWN into GLUCOSE which is USED for
ENERGY PRODUCTION (ADP -> ATP)
TRIGLYCERIDES are BROKEN DOWN into GLYCEROL and FATTY ACIDS which are USED for..
LIPID SYNTHESIS and STORAGE
& ENERGY PRODUCTION
GLYCOGEN (POLYSACCHARIDE) can be BROKEN DOWN into MALTOSE (DISACCHARIDE) by which ENZYME
AMYLASE (Salivary)
- hydrolyses alpha-1,4 glycosidic bonds
MALTOSE BREAK DOWN by MALTASE into..
GLUCOSE (x2)
SUCROSE BREAK DOWN by SUCARASE into..
GLUCOSE & FRUCTOSE
LACTOSE BREAK DOWN by LACTASE into..
GLUCOSE & GALACTOSE
GLYCOGEN BREAK DOWN by AMYLASE into…
MALTOSE
MONOSACCHARIDES (gluctose, fructose, galactose) are ABSORBED into Blood stream (to liver) by/via which CELLS
ENTEROCYTES
- ACTIVE TRANSPORT
how is GLUCOSE TRANSPORTED across ENTEROCYTES into BLOOD stream
at blood end: Na+ ACTIVELY PUMPED OUT by
Na+/K+ ATPase
- establishes a conc. gradient
at BRUSH BORDER of enterocyte:
NA+ GLUCOSE SYMPORTER
as Na+ diffuses IN, GLUCOSE CARRIED WITH IT
how is GLUCOSE TRANSPORTED across ENTEROCYTES into BLOOD stream
brush border: GLUT5 TRANSPORTER
blood end: GLUT 2 tranports FRUCTOSE and Glucose/GALACTOSE
does FRUCTOSE ABSORPTION use NA+
NO
GLUT5 and GLUT 2 TRANSPORTERS
what is SHORT BOWEL SYNDROME
a condition in which your body is UNABLE to ABSORB ENOUGH NUTRIENTS from foods
because you don’t have enough small intestine
NA+ CONC should be ABOVE …. in JEJUNAL LUMEN for WATER ABSORPTION (transported with Na+)
ABOVE 90 mmol/L
what is there PRODUCTION and ABSORPTION of in the LARGE INTESTINE (COLONIC FERMENTATION)
SHORT CHAIN FATTY ACIDS
- ANAEROBIC BACTERIA BREAK DOWN CARBOHYDRATES into short chain fatty acids (& gases)
COLONIC FERMENTATION in LARGE INTESTINE GENERATES…
ENERGY
(eg butyrate fatty acid - energy source)
800kcal a day can be generated from COLONIC FERMENTATION and Absorption
NON-DIGESTIBLE POLYSACCHARIDES in LARGE INTESTINE are BROKEN DOWN into SHORT CHAIN FATTY ACIDS and GASES (H2) By which BACTERIA?
FIIRMICUTES