lecture 26 - vitamins and minerals

Question 1

what are vitamins

Answer 1

organic substances = made by plants and animals
- always contain carbon as they are organic

Question 2

how are water soluble vitamins absorbed, secreted and stored

Answer 2

absorbed in portal blood, excreted in urine when plasma levels exceed renal thresholds

• not absorbed in large quantities

Question 3

what system do fat soluble vitamins enter and how are they stored

Answer 3

initially enters the lymphatic system as part of chylomicron

• stored in greater quantities = mainly liver, adipose tissue and cell membranes

Question 4

what are minerals

Answer 4

inorganic elements = come from soil and water, absorbed by plants or eaten by animals

Question 5

what are minerals responsible for

Answer 5

• structural functions involving skeleton and soft tissues
• regulatory functions including neuromuscular transmission, blood clotting, oxygen transport and enzymatic activity

Question 6

what are macro molecules

Answer 6

Ca, p, Mg, Na, K, Cl

• required in amounts greater than 100mg/day

Question 7

what are minor minerals

Answer 7

Fe, Zn, Se, I, Cu, Cr, Mn, Mo

required in less than 100mg/day

Question 8

what do enzymes do

Answer 8

make reaction go faster by lowering activation energy

Question 9

what do co enzymes do

Answer 9

are organic carrier molecules
(involved in transferring things from one molecule to another)

Question 10

what are co factors

Answer 10

more general term for small molecules required for the activity of their associated enzyme

• not strictly carrying something - may stabilise enzyme or substrate

Question 11

what is thiamine

Answer 11

serves as a co enzyme in the form of thiamine pyrophosphate (TPP) in a variety of metabolic processes

Question 12

examples of where thiamine serves as a co factor in carbohydrate metabolism

Answer 12

pyruvate dehydrogenase = converting pyruvate to acetyl CoA

a-Ketoglutarate dehydrogenase = converting a-Ketoglutarate to succinate in the citric acid cycle

Question 13

what does a thiamine deficiency cause

Answer 13

adverse consequences on energy production and nutrient metabolism = affecting cardiovascular, muscle tone and immune systems

Question 14

differences between wet and dry beriberi

Answer 14

in rarer cases, wat beriberi can cause congestive heart failure that leads to edema (overabundance of fluid in the tissues)