Biochem: Vitamins and Coenzymes
Terms
undefined, object
copy deck
- Vitamins are so called because...
-
they are necessary for life (vita) and were all believed to have an AMINE group thus... VITAmin.
(Actually, Vitamin C has NO amino group) - Before use, all vitamins (with very few exceptions) are converted to _________.
- Coenzymes
- Historically two types of molecules were shown to be important in almost all reactions in the body... they are__________? and how are they told apart?
-
Enzymes (proteins) and Vitamins (coenzymes/cofactors)
they are told apart because the enzymes are NOT heat stable they denature and vitamins ARE heat stable. -
Vitamin B1
Name:
Coenzyme:
Chemistry:
Required for: -
Thiamin (thiol & amine groups
Thiamin pyrophosphate (TPP)
Decarboxylation reactions
Group transfer molecules (by adding transfer molecules to carboxyl of phosphate group) - Vitamin B1 or thiamin deficiency is common in ________ and causes __________ symptoms.
-
Alcoholics.
Loss of apetite, constipation
Mental depression, fatigue
Wernecke-Korsakoff syndrome (confusion and weak eye movements)
beri beri (CNS (dry) and Cardiovascular(wet)) - it is believed what percentage of the public suffers from vitamin B deficiencies?
- 2/3
-
Vitamin b2
Named?
Converted to Coenzyme?
Purpose? -
Riboflavin (necessary SOLUBLE growth factor)
2 different INSOLUBLE conenzymes FMN and FAD.
Redox reactions these molecules become reduced. - Riboflavin is known to have what kind of bonding? What is a riboflavin deficiency called and what are symptoms?
-
Very tight bonding to proteins.
Riboflavin deficiency and causes lesions and glossitis. -
Vitamin B3
2 other Names:
Converted to:
Purpose: -
Niacin or Nicotinamide (pyrridine with COOH group)
2 SOLUBLE coenzymes NAD and NADP.
Redox reactions- specifically Hydride transfers (H-). (however realize that FAD and FADN the coenzymes of riboflavin are INSOLUBLE whereas NAD and NADP the coenzymes of niacin are SOLUBLE). - Why isnt niacin technically a vitamin?
- Because vitamins are molecules that are absolutely essential and must come from the diet. Niacin however can be made in small amounts by the liver.
- Niacin deficiency is said to cause the three D's they are...
-
Dementia
Dermititis
Diarrhea -
Vitamin B5
Named:
Converted to:
Function:
Deficiency: -
Pantothenic Acid
Coenzyme A
Acyl transfer (helps break down fats, proteins and carbs)
Burning feet syndrome - In both vitamins and coenzymes where is it that the reactions usually take place on the molecules?
- They take place on the alpha carbon of a carbonyl or other EWG. Recall that carbonyl is highly electron withdrawing as are some other molecules namely N and S and thus make the adjacent carbon highly reactive.
-
Vitamin H
Vitamin B1
Name:
Coenzyme:
Chemistry:
Required for -
Biotin
Biocytin (lysine +biotin)
Amino group
Carboxyllation rxns (CO2 carrier)
Deficiency found in Weightlifters and individuals on antibiotics. Eggwhites contain albidin which binds tightly to biotin and intestinal bacteria make biotin. -
Vitamin C
Name:
Conezyme:
Chemistry:
Required for:
Deficiency: -
Ascorbic Acid
Ascorbate Acid
?
Synthesis of tissue and production of collagen.
Scurvy- No collagen in capillaries and therefore have bursting capillaries (red-faced). - Fat soluble vitamins
-
A- vision, modifying proteins
D- controls Calcium levels
E- Redox reagent (no toxicity
K- clotting reactions