Exam Q-cards (1-4) Flashcards
Which monosaccharide has a slower rate of uptake from the digestive tract?
Fructose
The digestion of disaccharides occurs mainly in which location?
Upper small intestine
. The digestive enzymes which achieve this are collectively known as ………
Disacharidases
What is the name of the key enzyme involved in the breakdown of polysaccharides?
Alpha amylase
By which transport mechanism are monosaccharide’s taken over the basolateral border
and into portal circulation?
Facillitated diffusion
Glucose is up taken into cells via ………
Glucose transporters
What is the name of the glucose transporter which is regulated by insulin?
GLUT 4
Which three nutrients are required for the insulin receptor to function optimally?
Chromium, glutamine, B3
How do short chained fatty acids travel through circulation?
Attached to albumin
How do short chained fatty acids travel through circulation?
Peptides
What two mechanisms are utilised to transport free amino acids across the basolateral
border? What reason may designate the use of one transport over the other?
High - diffusion
Low - sodium dependant pathways
What group of enzymes hydrolyse a protein?
Proteases
What syndrome allows small oligopeptides to enter circulation via paracellular or
intercellular routes, which can cause inflammatory reactions?
Leaky gut
Name two carrier systems which transport amino acids into the liver?
Diffusion
Sodium dependant transport
What substance is necessary to reform ascorbate from dehydroascorbate and is essential
for vitamin C metabolism?
Glutathione
Is the absorption of vitamin C influenced by intake concentration? Explain?
Yes, after the body ingests more than 1000mg it cant absorb more than 50%
Which cells in the human body have the highest concentration of vitamin C?
Adrenal + pituitary glands
Vitamin C is necessary to activate an enzyme responsible for energy production and
collagen synthesis. Name this enzyme
Hydroxylase
Name two co-enzyme/active forms of thiamine?
Thiamin di-phosphate
Thiamin tri-phosphate
Name three foods which contain anti-thiamine factors?
Raw fish
Tea
Coffee
Blueberries
What are the group of enzymes which break the phosphate bonds with thiamine prior to
absorption?
Phosphatases
What inhibits thiamin transporters ThTr1 + ThTr2
Alcohol
By what mechanism does the uptake of B1 occur into cells?
Active transport by ThTr1 + ThTr2
What are the two co-enzyme forms of riboflavin?
Flavin mononucleotide
Flavine adenine dinucleotide
Name three antagonists of vitamin B2?
Alcohol, sunlight, thryoid disease
Which protein carrier transports majority of B2 through circulation?
Albumin
Vitamin B3 may also be synthesized in the liver from which amino acid?
Trytophan
By which two mechanisms does B3 get absorbed from the intestine at the brush border?
High - Passive diffusion
Low - sodium dependent active transport
What is the coenzyme form of pantothenate?
Coenzyme A
How is B5 mainly transported in circulation?
RBC
stored in liver and muscles
Name the three phosphorylated coenzyme forms of pyridoxine?
Pyridoxine phosphate
pyridoxal phosphate
pyridoxamine phosphate
What is the active form of B6 known as?
Pyridoxal-5-phosphate
How is B6 absorbed across both the brush and basolateral border?
Passive diffusion
Which enzyme and chemical are required to release B12 from peptide bonds in foods?
Pepsin
Hydrochloric acid
What is the name of the glycoprotein synthesized by the gastric parietal cells, although
functions in the small intestine to aid B12 absorption?
Intrinsic factor
. Name the mineral that is required for B12 absorption?
Calcium
What is the major storage form of B12 in the liver?
adenosylcobalamin
.In the circulation, vitamin B12 primarily travels bound to a protein named…….
Transcobalamin 2
Name 3 factors which may inhibit the absorption of folate?
alcohol
zinc deficiency
lentils, oranges
How does most of the folate travel through circulation?
folate binding proteins
Colonic bacteria can produce biotin intrinsically: True or False
true
. How does the absorption of vitamin A take place over the brush border?
active transport via micelle
Inside the enterocyte, which B vitamin is needed to form retinol from beta carotene?
Niacin
Name two substances which may enhance vitamin A absorption?
vitamin E, fat, fibre
Describe the process by which vitamin D can be synthesized by sunlight and
subsequently transported to tissues?
7-dehydrocholesterol converts pre-vitamin D to blood with chylomicrons then its activated by NADPH to 25OHD and stored in tissues
Calcium is transported across brush border by………..transporter channels and assisted
in its travel across (inside) the intestinal cells by………carrier protein.
TRPV6 and calbindin
What are the two mechanisms of phosphorus absorption and why would one method be
utilised over another?
high - passive diffusion
low - sodium dependant active transport
How is chromium mainly transported through circulation?
bound to transferrin
What is the name of the receptors which facilitate the transport of copper into cells from
circulation?
ceruloplasmin receptors
Name the compound found in the cruciferous vegetables that are known to act as iodine
inhibitor?
goitrogen
.By which mechanism is iodine taken up into the thyroid?
active transport
Name two transport proteins which transport the thyroid hormones T3 and T4 through
circulation?
thyroxine binding globulins
albumin
Iron travels in the blood bound to what?
transferrin
. Iron’s storage form is called…..
ferritin
Name two ways manganese is transported through circulation.
albumin
alpha-2 macroglobulin
Iron competes for absorption with manganese. Why may this be the case?
share the same DMT transporter
. What form of selenium is thought to be better absorbed?
selenomethionein
Name three other minerals are known to use the same transporter as zinc.
iron, manganese, copper
Vanadium mimics the action of which hormone?
Insulin
