Nutrients and Digestion Flashcards
what are the 3 monosaccharides?
glucose
galactose
fructose
what are the 3 disaccharides?
lactose
sucrose
maltose
what type of bonds are glucose monomers held together by in disaccharides?
glycosidic bonds
what type of bonds are glucose monomers linked together by in starch?
alpha 1,4, glycosidic bonds
what type of bonds are glucose monomers linked together by in cellulose?
beta 1,4 glycosidic bonds
what is lactose broken down into and by what enzyme?
lactase
glucose + galactose
what is maltose broken down into and by what enzyme?
maltase
glucose + glucose
what is sucrose broken down into and by what enzyme?
sucrase
glucose + fructose
what is the term sed for cellulose because we cannot digest it?
dietary fiber
because we don’t produce cellulase, how do vertebrates digest it?
by bacterial enzymes
what enzyme breaks polysaccharides into disaccharides?
amylase
what transporter is used in the transport of glucose and galactose from the cell into the blood?
GLUT - 5
what transporter is used in the transport of fructose from lumen to cell?
GLUT- 2
what transporter is used in the transport of glucose and galactose from lumen to cell?
SGLT1
what transporter is used in the transport of fructose from cell to blood?
GLUT - 5
what type of bond are polymers of amino acids linked by?
peptide bonds
what are the enzymes which break down proteins and peptides into amino acids?
peptidases / proteases
what are the 2 different peptidases?
exopeptidases - act on the terminal branches of the peptides: amino peptidases and carboxypeptidases
endopeptidases - act on the inside of the peptide
name 2 transporters which are used in the transport of amino acids into the cell.
SAAT1 and pepT1
what is the most common transporter used int he transport of peptides?
PepT1
how does the transport of di peptides occur?
di and tri peptide amino acid transporter.
occurs in microclimate (acidic conditions) = higher abundance of H ions
dependant on H ions (protons) to drive peptide into cell through PepT1
H ions then leave the cell back into the lumen
what is considered a small protein / peptide?
3-10 amino acid chains in length
what are almost all fats ingested in the form of?
triacylglycerides
where are fats digested ?
the small intestine
what are fats digested by?
pancreatic lipase
what does lipase digest triacylglycerides into?
monoglyceride + 2 fatty acids
what is emulsification and why does it happen?
divides large lipid droplets into smaller ones because digestion occurs on the surface of the droplet therefore if they are large then there is not a large surface area
by making them smaller - surface area increases
what are miscalles made up of?
monoglyceride + fatty acids + bile salts + phospholipids
what is the purpose of micelles?
miscele enhances speed of digestion by storing the monoglycerides and fatty acids
the then release a small amount into solution
(they are soluble due to bile and phospholipids)
they are then able to diffuse across the membrane
what happens when fatty acids and monoglycerides enter the epithelial cell?
they enter the set where they reform into triacylglycerides
released in a vesicle then pass through the golgi apparatus
they then leave the cell through serosal membrane and enter the extracellular fluid
what are triglycerides in extracellular fluid called?
chylomicrons
what vitamins are fat soluble?
A , D , E , K
what vitamins are water soluble?
B group, C and folic acid
where is iron absorbed?
across the intestine
after iron is absorbed where is it transported and by which transporter?
transported into the duodenal enterocytes by DMT1
how is iron stored intracellularly?
iron + protein = ferritin
what happens to unbound iron?
transported into the blood and binds to transferritin
what condition has decreased ferritin levels?
anaemia
what condition has more iron bound in enterocytes than in the blood?
hyperaemia
what condition has more iron released to the blood ?
anaemia (decreased ferritin levels)
