5 - Vitamins and minerals 1 Flashcards
Define recommended dietary allowance of nutrients
The average daily nutrient intake level which meets the needs of 97% to 98% of healthy people in a particular category.
What are the fat soluble vitamins
What are the distinguishing features of fat soluble vitamins in terms of storage and toxicity
A,D,E and K
ARE stored in the human body (in adipose tissues do to their lipophilic nature)
Toxicity can occur from excessive consumption, leading to accumulation.
What are the water soluble vitamins
What are the distinguishing features of ws vitamins in terms of storage and toxicity.
C and B vitamins
B vitamins = thamin, riboflavin, niacin, vitamin B6, vitamin B12, pantothenic acid, biotin and folate.
Not stored in the human body (excess secreted in urine)
Toxicty unlikely, occurs as a result of excess supplementation
What is the name for vitamin B? What is the other name for vitamin C? What is vitamin D essential for? What is vitamin E essential for? What is vitamin K essential for?
B = Thiamin C = Ascorbate D - Bone development E - Reproduction F - Blood coagulation
Inorganic or organic?:
Vitamins
Minerals
Vitamins = organic Minerals = inorganic
What body processes are minerals required for?
Regulation of fluid Energy production Bone and blood health Structural stability of proteins Cofactors
What are the names of the major minerals?
How much major minerals are needed per day?
How much is present in our body?
Calcium, phosphorus, sodium, potassium, chloride, magnesium, sulfur.
Greater than 100mg/day is needed
Amount present in body is at least 5000mg/5g
What are the names of the minor minerals?
How much major minerals are needed per day?
How much is present in our body?
Iron, zinc, copper, manganese, fluoride, chromium, molybdenum, selenium, iodine
Less than 100mg/day is needed
Less than 5000mg/5g is present in body
Vitamins are inactive precursers before being activated by chemical modification.
What functions can an active vitamin carry out (specify vitamins for each process)
Coenzyme (B/K)
Antioxidant (A,C,E)
Signalling molecule (A,D,E)
Alter gene expression (D)
What are
Coenzymes
Cofactors
Coenzymes: non-protein substances that enhance or are necessary for enzyme activity.
Some are catalytic, others stochiometric
Cofactors: typically minerals, required for enzyme activity (structure or function).
Many enzymes contain one or more metal ions in their structure. Some are _____, some are functional.
Structural.
Functional.
Zinc is a trace mineral. Give some functions in the body.
Catalytic role in enzymes including DNA/RNA polymerases and dehydrogenase enzymes
Structural role - ‘zinc finger’ domains. Carboxypeptidase A.
Can bind to transcription factors - regulating gene expression.
What role does Zinc play in carboxypeptidase A
Catalytic site contains a zinc ion that helps to stabilise the transition intermediate.
Give the main roles of the following trace minerals: Iron Copper Iodine Selenium Fluoride
Iron: Haemoglobin, binds to oxygen
Copper: cofactor (eg antioxidants and oxi phos)
Iodine: Component of thyroxine and triido thiroxine
Selenium: found in selenoproteins. Antioxidant, reproduction, immune system.
Fluoride: Development of enamel
What are the roles of the electrolytes and what are their intra and extra concentrations (high or low is fine)
Sodium and Potassium
> Regulate fluid in-take and excretion
Secretion of digestive enzymes depends on electrochemical gradients in small intestinal cells
Nutrient absorption (carbohydrate and protein) requires electrochemical gradient
Transmission of nerve impulses and muscle contraction
Maintained by a diverse range of passive and active transport proteins
> High intracellular potassium concentrations
High extracellular sodium concentrations
