Biochemical Nutrition Flashcards
Calories required to maintain body weight:
- Sedentary
- Moderate activity
- Very active
- 30 kcal/kg/day
- 35
- 40
Why do you need to have vitamins by diet?
They are organic compounds that cannot be synthesized in adequate quantities
- Many vitamins act as what 3 things for enzymes?
2. Vitamins are required for what 3 things for normal cellular function
- Cofactor, coenzymes, or prosthetic groups
2. Growth, differentiation, and maintenance
- What is the biologically active form of vitamin b1
- Serves as a coenzyme for what enzyme? Converts what to what?
- Serves as a coenzyme for what process? What enzymes are involved in this process?
- Thiamine pyrophosphate
- Transketolase (ribose 5 p -> glyceraldehyde 3 p)
- Oxidative decarboxylation in TCA cycle (pyruvate dehydrogenase and alpha ketoglutarate dehydrogenase)
Thiamine deficiency will lead to what 2 disorders?
Beriberi and wernicke-korsakoff syndrome
Beriberi:
- Common in areas where what food is major part of the diet?
- Wet beriberi affects? Causes what 2 conditions?
- Dry beriberi affects? Causes?
- Polished rice
- Heart; heart failure and weakened capillary walls
- Peripheral nerves; wasting/partial paralysis
Wernicke-Korsakoff syndrome:
- Associated with what?
- Caused by what 2 things?
- 3 symptoms?
- Chronic alcoholism
- Dietary insufficiency or impaired intestinal absorption of the vitamin
- Apathy, loss of memory, and nystagmus (eyes back and forth)
Riboflavin (vitamin B2)
- 2 biologically active forms?
- These active forms are important for flavoenzymes that catalyze?
- Riboflavin deficiencies may arise in newborns treated for ?
- Deficiency symptoms include what 3 things?
- Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)
- Oxidation or reduction of a substrate (electron transfer)
- Hyperbilirubinemia by phototherapy
- Dermatitis, cheilosis (fissuring at the corners of the mouth), and glossitis (tongue appears purple)
Niacin (B3)
- 2 biologically active forms
- These forms serve as coenzymes for?
- Whats a precursor for niacin?
- __ mg of tryptophan can generate 1 mg of niacin
- Depending on what food can cause niacin deficiency?
- NAD+ and NADP+
- Oxidation-reduction reactions (ETC, TCA)
- Dietary tryptophan
- 60mg
- Corn
- Deficiency of niacin can cause what disease? 3 symptoms of this disease
- Niacin causes decrease in __ and __
- Pellagra; dermatitis, diarrhea, dementia (skin, GIT, CNS symptoms)
- Plasma triglycerides and cholesterol (in VLDL and LDL) - decrease in lipolysis
Pantothenic Acid (B5)
- Component of? Which functions in the transfer of?
- Role in ?
- Is deficiency rare?
- Coenzyme A; acyl groups
- Synthesis and oxidation of fatty acids
- Yes
Pyridoxine (B6)
- Pyridoxine, pyridoxal, and pyridoxamine are all derivatives of?
- Biologically active coenzyme?
- Functions as a coenzyme for those in reactions that involve?
- What drug can induce B6 deficiency?
- Deficiency is common in what 3 kinds of people?
- What is unique about B6
- Pyridine
- Pyridoxal phosphate
- Amino acids
- Isoniazid
- Alcoholics, women who take contraceptives, and some newborns
- Only water soluble vitamin that leads to toxicity
Biotin (B7)
- Coenzyme in what kind of reactions?
- Why is deficiency rare?
- What is avidin and what does it do
- 5 symptoms of deficiency
- Carboxylation
- It is widely distributed in food and large quantity supplied by intestinal bacteria
- A glycoprotein in raw egg whites which binds biotin and prevents its absorption from the intestine
- Dermatitis, alopecia, glossitis, loss of appetite and nausea
Folic acid (folate)(B9)
- Key role in what kind of metabolism?
- Essential for __ of several compounds
- Humans need folate in order to __; so it is especially important during periods of __
- Active form?
- One carbon
- Biosynthesis
- Synthesize and repair DNA; rapid cell division and growth
- Tetrahydrofolate (THF)
- THF is involved in the synthesis of what 3 things?
2. Folic acid deficiency will lead to ?
- Amino acids, purines, and thymidine monophosphate (TMP)
2. Megaloblastic anemia (aka macrocytic anemia)
Megaloblastic anemia:
- Accumulation of?
- Caused by diminished synthesis of what 2 things?
- Leads to an inability of cells to do what?
- Large immature red cell precursors in the bone marrow and blood
- Purines and TMP
- Make DNA (therefore they cannot divide)
- Microcytic anemia is deficiency in what 3 things? __ HgB concentration
- Normocytic anemia is caused by?
- Macrocytic deficiency in what 2 things? Hypersegmented __
- Iron, copper and pyridoxine; low
- Decreased number of cells
- Vitamin B12 and folate; neutrophils
- Folic acid deficiency causes what 2 neural tube defects?
2. Recommended folate dose for women of childbearing age
- Spina bifida and anencephaly
2. 0.4 mg/day
Cobalamin (B12)
- Key for what 2 things?
- Required for what 2 essential enzymatic reactions
- B12 is only synthesized by? So what type of people need to supplement with B12?
- How do animals obtain B12? (2)
- This is the only water soluble vitamin that
- Deficiency will lead to ?
- Normal functioning of the nervous system and for formation of blood
- Homocysteine to methionine and methylmelonyl CoA to succinyl CoA
- Microorganisms (not present in plants); vegans need to supplement
- From intestinal bacterial flora or by eating foods derived from other animals
- Can be stored in the liver
- Pernicious anemia
Pernicious anemia:
- Results from?
- So pernicious anemia leads to?
- When B12 reaches the blood, what does it bind to
- How do you diagnose it?
- Advanced cases show as __ symptoms
- Lack of intrinsic factor preventing absorption of B12
- Deficiency of B12 (not caused by deficiency)
- Transcobalmin
- Schilling test
- Neuropsychiatric
Ascorbic Acid (Vitamin C)
- Acts as a __ in several reactions
- Coenzyme for __ synthesis - so helpful for ?
- Facilitates the absorption of __
- Works as an __
- Deficiency leads to
- Reducing agent
- Collagen synthesis - wound healing
- Dietary iron from the intestine
- Antioxidant
- Scurvy