26 Flashcards
What is beriberi caused by?
A thiamine (vitamin B1) deficiency
Causes of thiamine deficiency
- dietary intake of thiamine
- anti-thiamine factors
What are vitamins?
Vitamins are organic
substances, which
means they’re made
by plants and animals
What are minerals
Minerals are inorganic
elements that come from
soil and water, and are
absorbed by plants or
eaten by animals
What is the main difference between vitamins and minerals
The primary difference between organic vs. inorganic compounds
is that organic compounds always contain carbon while
most inorganic compounds do not contain carbon. Also, nearly
all organic compounds contain carbon-hydrogen or C-H bonds.
Vatimins are fragile and can be destroyed by U.V light and heat
Minerals are much harder to destroy
How do different vitamins relate/ not relate ?
Not related chemically and differ in their physiological roles
Vitamins are ________ units and are not ______ _______
Vitamins are individual units and not linked together
Vitamins are _____ _______ but only requires in _____ ______ in the diet
Vitamins are essential nutrients but required only in small quantities in the diet
Which vitamin can our body make
Vitamin D
Water soluble and fat soluble vitamins
Yes
Yass
Vitamin absorbtion - fat souluble vs water soluble - differences - not examinabel
Fat soluble:
- initially enters the lymphatic system as a part of chylomicron
(Digested like fat by a micelle) - absorbed by fat
Water soluble:
- absorbed into portal blood
Water soluble vitamins where are they absorbed ?
Into portal blood
Where are water soluble vitamins excreted and when?
Generally excreted in the urine when plasma levels exceed renal thresholds
Are water soluble vitamins stored?
Not stored in large quantities in body tissues
- lower risk of toxicity
- therefore we must eat them more often
How is fat soluble vitamins is digested? Enter the body ? What part of the body?
Initially enters the
lymphatic system as part
of a chylomicron
Are fat soluble vitamins stored in the body? Where are they stored ?
Stored in greater quantities in body tissues – mainly liver, adipose and cell membranes
- higher risk of toxicity
Vitamin different divisions
How much of total body weight constitutes to minerals ?
4%
Minerals are responsible for
– Structural functions involving the skeleton and soft tissues
– Regulatory functions including neuromuscular transmission, blood
clotting, oxygen transport, and enzymatic activity
Mineral classification - Major (macro) - abundance in body? How much required by adults?
• Found in greater abundance in the body
• Required by adults in amounts greater than 100 mg/d
Mineral classification - trace (minor) - whys is called a trace? How much required by adults?
• Initially termed ‘trace’ because concentration in tissues not easily identified
• Required by adults in amounts < than 100 mg/d
Do not memorize, just appreciate the extent of physiological functions, food sources and consequences of inadequate intakes
Calcium
Iodine
Salismiuim - heart attack
Zinc
Do not memorize, just appreciate the extent of physiological functions, food sources and consequences of inadequate intakes
What do enzymes do?
Enzymes make reactions go faster by lowering the
activation energy
– Bind to their substrate at a location on the enzyme = active site
– But not all enzymes are able to catalyze reactions on their own
and need a co-factor or co-enzyme to function properly
What are cofactors
Co-factors are more general term for small molecules required for the activity of their associated enzyme
– Not strictly carrying something - might be stabilizing the enzyme or
substrate or helping the reaction convert substrates
Includes inorganic ions: Mg Mn Mo Se Fe
What is a co-enzyme
• Coenzyme are organic carrier molecules (carbon-based) that link to enzymes and are essential to the activitity of those enzymes
– Involved in transferring things from one molecule to another
– Many coenzymes are derived from vitamins
- belong to the larger group called cofactors
Vitamins and co-enzymes
Co-factor mineral example - DNA polymerase
• DNA polymerase enzyme is responsible for helping with DNA synthesis
• DNA is a very negatively charged molecule due to negative -ve charged phosphate groups
• DNA polymerase uses positive charge Mg ion as a co-factor to stabilize the negative charge
Beriberi - what does thiamine B1 do>
Thiamine (B1) serves as a coenzyme in the form of thiamine
pyrophosphate (TPP) in a variety of metabolic processes
What enzymes does TPP play a key role in? What are these enzymes involved in?
– Includes: transketolase, alpha-ketoglutarate dehydrogenase,
pyruvate dehydrogenase and branched chain alpha-keto acid dehydrogenase
– These enzymes are involved in the pathways that allow the
production of ATP, NADPH and ribose-5-phosphate that are critical for generating cellular energy and downstream production of amino acids, nucleic acids and fatty acids
What does thiamine definition refer to
Refers to a lack of thiamine
pyrophosphate (TPP)
Consequences of thiamine deficiency
thiamine deficiency has adverse consequences on energy production and nutrient metabolism = life threatening \
Affecting cardiovascular, nervous, muscle tone and immune systems
When was beriberi discovered ? By who?
• Discovered in 1897 by Christiaan Eijkman, Dutch physician and pathologist
BERI BERI Discovered in 1897 by Christiaan Eijkman, Dutch
physician and pathologist demonstrated that beriberi was caused by what?
caused by a poor diet
– Japanese navy sailing from Japan to Hawaii where 169 of 376
sailors contracted beriberi and 25 died -> infectious disease?
– Standard diet rations consisted mostly of polished white rice
– Another ship with crew along the same route fed a more
varied diet of meat, fish, barley, rice and beans -> diet induced
Animal studies: of beri Beri - what prevented it?
Feeding unpolished rice to chickens helped to prevent beriberi
White rice lacked some essential ingredient - which one?
Thiamine
Vitamin B1 is a ____-______ vitamin
Water soluble
Structure of thiamine B1- and TTP
- Aminopyrimidine ring linked to a thiazole ring by a methylene bridge
- reacts with ATP to form TPP (addiction of two phosphate groups)
Food sources if thiamine
Found in a wide variety of foodstuffs including seeds, beans, pork, spinach, cornflour and breakfast cereal
Thiamine deficit can arise in two ways:
• Insufficient intake from the diet include lower absorption
or higher excretion rates than normal due to alcohol
dependence, HIV/AIDS, medications
Early stages of thiamine deficiency
• Early stages, weight loss and anorexia, confusion, short-
term memory loss; muscle weakness and cardiovascular
symptoms (enlarged heart)
Most common effect of thiamine defincincy
• Most common effect is beriberi, characterized by
peripheral neuropathy and wastin
Symptoms of Dry Beri Beri
- impaired sensory, motor and reflex functions
What does wet Beri Beri cause (rare)
In rarer cases, wet beriberi causes congestive heart failure that leads to edema (overabundance of fluid in the tissues) in the lower limbs and, occasionally, death
Kiribati facts
- one of the most isolated counties in the world
- made up of 33 isalends strethcing across equator
- low lying nation with the highest point of many islands being only
a few meters above sea level
- vulnerable to climate chang and naturall disasters
- climate is warm and humid all heat; average rainfall is very high but unpredictable
- limited water respiurces
Kiribati - intake of thiamine?
Poor intake of thiamine due to a very limited food supply – poor
variety – and staple diet of white polished rice
Chronic alcoholism and thiamine
– ethanol reduces gastrointestinal absorption of
thiamine, liver thiamine stores and thiamine phosphorylation
Anti-thiamine factors (ATF) what do they do
react with thiamine to form an oxidized,
inactive product
What else related to Kiribati causes a thiamine depletion - ATF
– Large amounts of tea and coffee as well as chewing tea leaves
and betel nuts, are associated with thiamine depletion in humans
– Mycotoxins (molds) and thiaminases that break down thiamine in
food. Eating certain raw fresh-water fish, raw shellfish, or ferns
increase risk of thiamine deficiency because these foods contain
thiaminase that are normally inactivated by heat in cooking
Acute treatment of beriberi
• Thiamine supplementation either orally, IV or intramuscular
Long term treatment of beriberi
- can we put something like thiamine into common food
