Nutrient Digestion I (Carbohydrates and Proteins) Flashcards
what are the principle dietry constituents?
carbohydrtaes proteins fats vitamins minerals water
what are monosaccharides and what are examples of some?
hexose sugars 6C
glucose
galactose
fructose
what do monosaccharides break down to?
complex CHOs which are absorbed by small intestine
what are disaccharides?
two monosaccharides linked together by glycosidic bonds
what do disaccharides break down into?
constituent monomers by brush border enzymes in small intestine
what are examples of disaacharides?
lactose
sucrose
maltose
how do you make lactose?
glucose and galactose
how do you make sucrose?
glucose and fructose
how do you make maltose?
glucose and glucose
what are examples of polysaccharides?
starch
cellulose
glycogen
what is starch?
plant storage form of glucose
- amylose: glucose linked in straight chains
amylopectin: glucose chains highly branched
Glucose monomers linked by a-1,4 glycosidic bonds - hydrolysed by amylases (saliva, pancreas)
what is cellulose?
constituent of plant cell walls
Unbranched, linear chains of glucose monomers linked by B-1,4 glycosidic bonds
Dietary fibre (no enzymatic digestion in vertebrates - require bacteria (cellulase))
what is glycogen?
animal storage form of glucose
Glucose monomers linked by a-1,4 glycosidic bonds
what is transcellular transport?
Transcellular transport involves the transportation of solutes by a cell through a cell.[1] One classic example is the movement of glucose from the intestinal lumen to extracellular fluid by epithelial cells.
what is paracellular transport
Paracellular transport refers to the transfer of substances across an epithelium by passing through the intercellular space between the cells
what is vectorial transport?
The transport of an ion or molecule across an epithelium in only one direction (e.g. absorption of nutrients in the gut). Vectorial transport requires that transport proteins are nonrandomly distributed between the apical and basolateral plasma membrane.
what is the difference between the apical and basolateral membrane?
the term basolateral membrane or serosal membrane refers to the cell membrane which is oriented away from the lumen of the tubule, whereas the term luminal membrane or apical membrane refers to the cell membrane which is oriented towards the lumen.
what is a symporter?
can transport two things at once
what is an example of a symporter and the carrier for glucose and sodium?
SGLT1
what are polymers of amino acids linked togerther by?
peptide bonds
what are enzymes called that hydrolyse peptide bondsand reduces protiens to amino acid?
proteases or peptidases
what are small poteins that are 3-10 amino acids in length?
peptides
