Nutrients and Absorption Flashcards
Give an example of monosaccharides
Glucose, galactose, fructose
Where are monosaccharides broken down?
The small intestine
Describe the structure of disaccharides
Two monosaccharides linked together by a glycosidic bond
Where are disaccharides broken down?
The brush border of the small intestine
What bonds are present in starch molecules?
Alpha 1-4 Glycosidic Bonds
What hydrolyses starch?
Amylases
What bonds are present in cellulose?
Beta 1-4 Glycosidic bonds
What bonds are present in glycogen?
Alpha 1-4 Glycosidic bonds
Describe transcellular transportation
Movement of molecules from the apical membrane to the basolateral membrane (or vice versa) without the need for transport proteins
Describe vectorial transport
Movement of molecules across membranes requiring transport proteins
Describe the glucose symport
Na/KATPase pumps 2 K ions in and 3 Na ions out into the blood, creating a downward gradient. The SGLT1 protein uses the energy fro this gradient to transport Na ions and glucose across the apical membrane. Na is used in the Na/KATPase and glucose enters the blood via a GLUT-2 transport protein
What proteins transport fructose?
GLUT-5 and GLUT-2
What bonds link amino acids to make protein chains?
Peptide bonds
What hydrolyses peptide bonds?
Proteases or peptidases
Where is fat digested?
The small intestine
In what form is fat digested?
Triacylglycerol
What enzyme aids in fat digestion?
Lipase
Triacylgycerol is broken down by lipase into what?
Monoglyceride and 2FA’s
Define emulsification
Dividing large droplets into smaller droplets to increase surface area and accessibility to lipase action
Name the two things that are required during emulsification
Mechanical disruption and an emulsifying agent
What makes up a micelle ?
Bile salt + monoglyceride + FA + Phosopholipid
What does vitamin B12 bind to?
Intrinsic factor in the stomach
What occurs when someone is B12 deficient?
Pernicious anaemia –> failure of rbc maturation
what does iron bind to?
Ferritin
Where does ubound iron enter?
The blood
What does iron in blood bind to ?
Transferrin
What is hyperaemia?
Increased ferritin levels which means more iron is bound in enterocytes
What is anaemia?
When body’s ferritin levels are decreased meaning there is more iron released to blood
