Vitamin and Metabolic Pathways Flashcards
(113 cards)
1
Q
What is the absorption method for water-soluble vitamins?
A
Directly into bloodstream
2
Q
What is the absorption method for fat-soluble vitamins?
A
With dietary fats, lymphatic system
3
Q
How are water-soluble vitamins transported in the body?
A
Freely in bloodstream
4
Q
How are fat-soluble vitamins transported in the body?
A
Bound to proteins/lipoproteins
5
Q
What is the storage capability of water-soluble vitamins?
A
Minimal (except B12, B6); circulate freely in water-filled parts of the body
6
Q
What is the storage capability of fat-soluble vitamins?
A
Extensive storage (liver/adipose tissue)
7
Q
How are water-soluble vitamins excreted from the body?
A
Kidneys (urine)
8
Q
How are fat-soluble vitamins excreted from the body?
A
Rarely excreted, except vitamin K
9
Q
What is the toxicity level of water-soluble vitamins?
A
Generally low, excess excreted
10
Q
What is the toxicity level of fat-soluble vitamins?
A
Possible from supplements
11
Q
What is the intake requirement for water-soluble vitamins?
A
Frequent intake (daily/few days)
12
Q
What is the intake requirement for fat-soluble vitamins?
A
Periodic intake (weeks/months)
13
Q
What is the full name of Thiamin?
A
Vitamin B1
14
Q
What are some food sources of Thiamin?
A
- Meats - Pork chops
- Lentils and beans
- Soy milk
15
Q
What is a major function of Thiamin?
A
Key to energy metabolism
16
Q
What is the role of TPP in energy metabolism?
A
Catalyst for decarboxylation of pyruvate
17
Q
What does Thiamin help form for the Citric Acid Cycle?
A
Acetyl CoA
18
Q
What is the main function of Riboflavin?
A
Helps convert food (carbs) to fuel (glucose)
19
Q
What are some food sources of Riboflavin?
A
- Proteins
- Vegetables – mushrooms, spinach
- Fortified grains, breads, cereals
20
Q
What are the two coenzymes that Niacin forms?
A
- NAD+
- NADP
21
Q
What is the full name of Niacin?
A
Vitamin B3
22
Q
What are some food sources of Niacin?
A
- Whole grain
- Beef liver
23
Q
What is a major function of Pantothenic acid?
A
Synthesis of Coenzyme A
24
Q
What are some food sources of Pantothenic acid?
A
- Beef liver
- Breakfast cereals
- Shiitake mushrooms
- Sunflower seeds
25
What is the full name of Vitamin B6?
Pyridoxal, Pyridoxine, Pyridoxamine
26
What are some food sources of Vitamin B6?
* Poultry
* Fish (salmon)
* Beef
* Organ meats
* Spinach
* Nuts
* Fortified cereals
27
What does Biotin improve?
Hair, nail, and skin health
28
What is the main function of Folate?
DNA synthesis
29
What are some food sources of Folate?
* Leafy greens
* Beef liver
* Legumes
* Asparagus
* Broccoli
* Orange juice
* Enriched grains and fortified cereal
30
What is the difference between Folate and Folic Acid?
Folate requires specific intestinal enzymes for digestion and is less bioavailable
31
What is the main function of Vitamin B12?
Necessary for red blood cell formation and neurological function
32
What is required for the absorption of Vitamin B12?
* Intrinsic factor
* Stomach acid
* Calcium
* Folate
33
What can interfere with Vitamin B12 absorption?
Lack of intrinsic factor, low stomach acid, Metformin
34
What is folate also known as?
Vitamin B9
## Footnote
Folate is essential for DNA synthesis and metabolism.
35
What can interfere with folate absorption?
* Lack of intrinsic factor
* Low stomach acid
* Metformin (used to treat type 2 diabetes)
## Footnote
These factors can hinder the body's ability to absorb folate effectively.
36
How is vitamin B12 absorbed in the stomach?
Vitamin B12 is bound to protein in food and is freed by hydrochloric acid and gastric enzymes
## Footnote
This process is essential for its subsequent absorption in the small intestine.
37
What complex is formed in the small intestine for B12 absorption?
B-12 binds to intrinsic factor to form the IF/B-12 complex
## Footnote
Intrinsic factor is produced by parietal cells in the stomach.
38
Where does the B-12 Intrinsic Factor complex attach for absorption?
The ileum
## Footnote
Special receptors on the intestinal lining facilitate this process.
39
What is one of the main roles of vitamin B12 in the body?
DNA synthesis and homocysteine metabolism
## Footnote
B12 works closely with folate to ensure proper DNA synthesis.
40
What happens when there is a deficiency of vitamin B12?
Impaired DNA synthesis leading to megaloblastic anemia
## Footnote
This condition results in the production of large, dysfunctional red blood cells.
41
What does B12 do in homocysteine metabolism?
B12 acts as a coenzyme for methionine synthase, converting homocysteine to methionine
## Footnote
Folate provides the necessary methyl group for this reaction.
42
What are some functions of vitamin B12?
* Keeps red blood cells healthy
* Helps make DNA
* Prevents megaloblastic anemia
* Regulates homocysteine levels
* Maintains nervous system health
## Footnote
These functions are crucial for overall health.
43
What is another name for vitamin C?
Ascorbic acid
## Footnote
Vitamin C is an essential nutrient with various roles in the body.
44
Where can vitamin C be found?
* Peppers
* Citrus fruits
* Papaya
* Broccoli
* Cabbage
* Berries
## Footnote
These are rich sources of vitamin C.
45
What is the primary function of vitamin C?
Acts as an antioxidant and aids in collagen formation
## Footnote
It also plays a role in immune function and enhances iron absorption.
46
True or False: Vitamin C is stable in the presence of heat.
False
## Footnote
Vitamin C is unstable when exposed to heat, cooking, or boiling.
47
What is the full name of vitamin A?
Retinoid
## Footnote
Vitamin A is crucial for vision and maintaining healthy tissues.
48
In what forms is vitamin A found?
* Retinol
* Retinal
* Retinoic acid
* Beta-carotene
## Footnote
These forms play various roles in the body, especially in vision.
49
What role does vitamin A play in vision?
Helps maintain the cornea and converts light energy into nerve impulses
## Footnote
This process is crucial for seeing in low light conditions.
50
What is the full name of vitamin D?
Calciferol
## Footnote
Vitamin D is important for calcium absorption and bone health.
51
What is the most biologically active form of vitamin D?
1, 25 dihydroxyvitamin D (D3, calcitriol)
## Footnote
This form is crucial for various bodily functions.
52
Name some food sources of vitamin D.
* Salmon
* Eggs
* Milk
* Salami
* Tuna
## Footnote
These foods are rich in vitamin D.
53
What can inhibit vitamin D synthesis in the skin?
* Melanin pigment
* Low sunlight exposure
## Footnote
Darker skin requires more sunlight for adequate vitamin D production.
54
What are some benefits of vitamin D?
* Assists in calcium and phosphorus absorption
* Protects against cognitive decline
* Regulates adipose cells
## Footnote
These benefits are vital for overall health.
55
What is the full name of vitamin E?
Alpha tocopherol
## Footnote
Vitamin E is known for its antioxidant properties.
56
What are some food sources of vitamin E?
* Peanut butter
* Nuts
* Oils
* Asparagus
* Avocado
## Footnote
These foods are significant sources of vitamin E.
57
What is a major role of vitamin E in the body?
Acts as an antioxidant to protect cell membranes
## Footnote
It prevents lipid peroxidation and reduces oxidative stress.
58
What can excessive amounts of vitamin E lead to?
Interference with blood clotting and increased risk of hemorrhage
## Footnote
This highlights the importance of moderation in vitamin E intake.
59
What is the full name of vitamin K?
Quinone family
## Footnote
Vitamin K is essential for blood clotting and bone health.
60
What are the main dietary forms of vitamin K?
* Phylloquinone (K1)
* Menaquinones (K2)
## Footnote
K1 is primarily found in plants, while K2 is found in animal products.
61
What is one function of vitamin K?
Helps with blood clotting
## Footnote
It is crucial for synthesizing clotting factors in the body.
62
What is choline important for?
* Neurotransmitter and phospholipid synthesis
* Emulsifier
* Methionine metabolism
## Footnote
Choline is vital for various metabolic processes.
63
What is carnitine's role in the body?
Transports long-chain free fatty acids into the mitochondria for energy metabolism
## Footnote
Vitamin C is required for its synthesis.
64
What deficiency is associated with thiamin?
Beriberi
## Footnote
This deficiency can cause neurological and cardiac issues.
65
What are olipids that are precursors to eicosanoids?
They serve a regulatory role in cells.
66
What is taurine?
A component of bile.
67
What is lipoic acid?
A component of metabolic reactions that remove CO2 from compounds, and is an antioxidant.
68
Identify the deficiency of thiamin.
Beriberi, which includes neurological and cardiac issues.
69
What is Wernicke-Korsakoff syndrome?
A degenerative brain disorder due to thiamine deficiency.
70
List symptoms of Wernicke-Korsakoff syndrome.
* Abnormal eye movement
* Staggering gait
* Distorted thought process
71
What is ariboflavinosis?
A deficiency of riboflavin characterized by sore throat, skin inflammation, and mouth sores.
72
What is pellagra?
A deficiency of niacin leading to dermatitis, diarrhea, dementia, and death.
73
List broader symptoms of niacin deficiency.
* Pigmented rash
* Discolored skin
* Bright red tongue
* Depression
* Apathy
* Headache
* Fatigue
* Memory loss
74
What increases the risk of niacin deficiency?
* Alcohol abuse
* Eating disorders
75
What are symptoms of vitamin B6 deficiency?
* Microcytic anemia
* Dermatitis
* Neurological disturbances
76
What are the symptoms of biotin deficiency?
* Hair loss
* Skin rash
* Neurological symptoms (rare)
77
What are the consequences of folate deficiency during pregnancy?
* Megaloblastic anemia
* Neural tube defects
78
What is spina bifida?
A condition where the spine forms improperly and bones fail to enclose the spinal cord.
79
What is anencephaly?
A condition where portions of the brain are malformed or missing, leading to death shortly after birth.
80
What characterizes megaloblastic anemia?
Abnormally large red blood cells (megaloblasts) due to folate deficiency.
81
What is pernicious anemia?
A type of 'destructive anemia' seen in stomach issues due to vitamin B12 deficiency.
82
What is scurvy?
A deficiency of vitamin C characterized by fatigue, weakness, irritability, and poor wound healing.
83
What are symptoms of vitamin A deficiency?
* Night blindness
* Xerophthalmia
* Keratinization
* Increased susceptibility to infectious diseases
84
What can cause vitamin A toxicity?
* Birth defects
* Liver damage
* Hair loss
* Reduced bone density
85
What is the role of calbindin?
A protein that binds calcium in intestinal cells.
86
How is vitamin D synthesized from UVB light?
UVB radiation converts skin cholesterol into previtamin D3, which is transformed into active vitamin D in the liver and kidneys.
87
What is anaerobic glycolysis?
A metabolic process converting glucose to pyruvate in the absence of oxygen.
88
What is the main outcome of aerobic glycolysis?
Complete oxidation of glucose to carbon dioxide and water, producing approximately 36-38 ATP.
89
What is the Cori cycle?
A metabolic pathway between muscles and the liver during anaerobic conditions.
90
What is beta oxidation?
A catabolic process by which fatty acids are broken down in mitochondria.
91
What is the purpose of amino acid metabolism?
To break down amino acids for energy production.
92
What is the ketogenic pathway?
A metabolic pathway producing ketone bodies from excess acetyl-CoA in the liver mitochondria.
93
What is the primary pathway for moderate alcohol consumption?
Alcohol dehydrogenase pathway.
94
What is the outcome of the citric acid cycle?
To oxidize acetyl-CoA and produce high-energy molecules (NADH, FADH2) and carbon dioxide.
95
What are the end results of the Krebs cycle?
3 NADH, 1 FADH2, 1 ATP, 2 CO2
## Footnote
The Krebs cycle is also known as the citric acid cycle or TCA cycle.
96
Where does the Electron Transport Chain (ETC) occur?
Inner mitochondrial membrane
## Footnote
The ETC is a series of protein complexes and other molecules that transfer electrons.
97
What is the purpose of the Electron Transport Chain?
Use electrons from NADH and FADH2 to generate ATP through oxidative phosphorylation
## Footnote
This process also produces water and regenerates NAD+ and FAD.
98
Fill in the blank: NADH and FADH2 donate electrons to complexes ______ and ______.
I, II
99
What is the final electron acceptor in the Electron Transport Chain?
O2
100
What causes Alcoholic Fatty Liver Disease (AFLD)?
Chronic alcohol consumption
## Footnote
This disrupts liver metabolism, leading to fat accumulation.
101
What mechanism leads to fat accumulation in Alcoholic Fatty Liver Disease?
Ethanol metabolism produces large amounts of NADH
## Footnote
Excess NADH inhibits fatty acid oxidation and promotes fatty acid synthesis.
102
What is a consequence of excess NADH in the liver?
Inhibits fatty acid oxidation and promotes fatty acid synthesis
## Footnote
This can lead to triglyceride accumulation in hepatocytes.
103
What is the cause of Non-Alcoholic Fatty Liver Disease?
Abnormal accumulation of fat in the liver not caused by alcohol consumption
104
What metabolic condition is associated with Non-Alcoholic Fatty Liver Disease?
Insulin resistance
## Footnote
Insulin-resistant cells do not effectively take up glucose and fatty acids.
105
What is the goal of the fed state (0-4 hours after eating)?
Store excess nutrients and maintain normal blood glucose
106
Which hormone is dominant in the fed state?
Insulin
107
What metabolic changes occur during the fed state?
* Glucose uptake (muscle, adipose)
* Glycogenesis (liver, muscle)
* Lipogenesis (fat storage)
* Protein synthesis
108
What inhibits gluconeogenesis during the fed state?
Insulin
109
What hormone increases during the feasting state?
Leptin
110
What happens during early starvation (24-48 hours)?
* Glycogen stores are depleted
* Glucose levels drop
* Gluconeogenesis kicks in
* Lipolysis occurs
* Ketone bodies begin forming
111
What is the main energy source during late starvation (days to weeks)?
Fat stores
112
Fill in the blank: The brain shifts to use ______ bodies to preserve muscle protein during starvation.
ketone
113
What slows down during late starvation to conserve lean tissue?
Proteolysis
