Question 1

Discuss the role of calcitonin in maintaining normal blood calcium concentration.

Accepted Answer

The answer of Discuss the role of calcitonin in maintaining...

Question 2

Although for micronutrients increasing the amount of a protein by directly inducing gene expression is certainly a common mechanism,we have encountered other mechanisms by which vitamins can regulate proteins.Provide one example of posttranslational modification,being as specific as possible.

Accepted Answer

The answer of Although for micronutrients increasing the amount of...

Question 3

7-dehydrocholesterol is the form of vitamin D that is added to fortify milk.

Accepted Answer

7-dehydrocholesterol is a precursor to vitamin D3 in the skin, not the form added to fortify milk. Vitamin D2 (ergocalciferol) or D3 (cholecalciferol) are typically used for fortification.

Question 4

Inadequate vitamin D intake has been associated with autoimmune conditions such as rheumatoid arthritis,Crohn's disease,multiple sclerosis,and type I diabetes.

Accepted Answer

Studies have shown that individuals with autoimmune conditions have lower levels of vitamin D and inadequate intake of vitamin D has been associated with an increased risk of developing autoimmune conditions.

Question 5

Match the factor to its correct action.
-XIa

Accepted Answer

Factor XIa activates factor IX in the intrinsic pathway of the coagulation cascade.

Question 6

Match the factor to its correct action.
-Xa

Accepted Answer

Factor Xa converts prothrombin into thrombin.

Answer: B
 Factor Xa creates insoluble fibrin for final clot formation.

Answer: A
 Factor Xa becomes activated in the presence of thromboplastin.

Answer: D
 Factor Xa works with factor IXa to activate factor X.

Answer: E
 Factor Xa does not activate factor IX but rather, factor IXa activates factor X.

Question 7

Subclinical vitamin K deficiency may be associated with diminished bone mineral density and increased fracture rates.

Accepted Answer

Subclinical vitamin K deficiency, which may occur due to inadequate intake or impaired absorption, has been found to have an impact on bone health. Vitamin K is involved in the regulation of calcium metabolism and bone formation, and deficiency can result in decreased bone mineral density and an increased risk of fractures. Studies have suggested that improving vitamin K status, such as through dietary supplements or increased consumption of vitamin K-rich foods, may help prevent and manage osteoporosis.

Question 8

Indicate: (1)the active form of vitamin K, (2)the general function of vitamin K,and (3)an example of the general function (this could be a specific reaction or simply indicate a pathway/ process where it occurs).Your answers do not need to be long!

Accepted Answer

The answer of Indicate: (1)the active form of vitamin K,...

Question 9

Match each vitamer with its function.
-11-cis retinal

Accepted Answer

11-cis retinal is needed for binding with opsin in the photoreceptor rod cells, allowing for visual perception.

Answer: E
 11-cis retinal can donate hydrogens to terminate propagation of membrane lipid peroxidation chain reactions, helping to prevent cell damage. The other options are not related to the function of 11-cis retinal.

Question 10

Match the factor to its correct action.
-XIIIa

Accepted Answer

Factor XIIIa is responsible for creating insoluble fibrin for final clot formation.

Answer: A
 Factor VIIa becomes activated in the presence of thromboplastin.

Answer: C
 Thrombin is the active form of factor II and it converts prothrombin into thrombin.

Answer: D
 Factor VIII works with factor IXa to activate factor X.

Answer: E
 Factor IXa activates factor X.

Question 11

A good source of vitamin D is milk,because it is fortified with 1,25-(OH)₂-vitamin D₃.

Accepted Answer

Milk is fortified with vitamin D, but typically with vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol), not with the active form 1,25-(OH)₂-vitamin D₃ (calcitriol).

Question 12

Match each vitamer with its function.
-retinoic acid

Accepted Answer

Retinoic acid, a metabolite of vitamin A, is transported into the nucleus where it influences gene transcription, including that of keratin proteins, affecting skin health and cell differentiation.

Question 13

Match the factor to its correct action.
-VII

Accepted Answer

The answer of Match the factor to its correct action.
-VII
...

Question 14

Regulation of Proteins by Vitamins: Micronutrients,such as vitamins,typically regulate gene expression (i.e.,induction)directly.Use either vitamin D or vitamin A to illustrate this concept-be complete and thorough in your answer.Do not simply draw a diagram; include some discussion and make sure everything is labeled and/or defined.

Accepted Answer

The answer of Regulation of Proteins by Vitamins: Micronutrients,such as vitamins,typically...

Question 15

Match each vitamer with its function.
-alpha-tocopherol

Accepted Answer

Alpha-tocopherol donates hydrogens to terminate propagation of membrane lipid peroxidation chain reactions.

Question 16

Match the factor to its correct action.
-VIIa

Accepted Answer

Factor VIIa, in conjunction with tissue factor, activates Factor X directly and also activates Factor IX in the coagulation cascade, which then forms a complex with Factor VIIIa to further propagate the clotting process. The specific action of Factor VIIa working with Factor IXa to activate Factor X is a critical step in the coagulation pathway.

Question 17

Vitamin A enhances vitamin K absorption and increases the plasma concentration of vitamin E.

Accepted Answer

Vitamin A does not directly enhance vitamin K absorption or increase the plasma concentration of vitamin E. These vitamins have distinct roles and mechanisms of absorption in the body.

Question 18

Match each vitamer with its function.
-calcitriol

Accepted Answer

Calcitriol interacts with nuclear VDR to increase calbindin, which helps in calcium absorption.

Answer: B 
 Vitamin K is required for carboxylation of glutamic acid, which is important for blood clotting.

Answer: C 
 Retinal is needed for binding with opsin in the photoreceptor rod cells, which is important for vision.

Answer: D 
 Vitamin D is transported into the nucleus to affect gene transcription of keratin proteins, which is important for skin health.

Answer: E 
 Vitamin E donates hydrogens to terminate propagation of membrane lipid peroxidation chain reactions, which helps protect cells from oxidative damage.

Question 19

Match each vitamer with its function.
-hydroquinone (KH₂)

Accepted Answer

The answer of Match each vitamer with its function.
-hydroquinone (KH₂)
...

Question 20

Explain the process by which rhodopsin is formed.

Accepted Answer

The answer of Explain the process by which rhodopsin is...

Quiz 10: Fat-Soluble Vitamins

Discuss the role of calcitonin in maintaining normal blood calcium concentration.

Although for micronutrients increasing the amount of a protein by directly inducing gene expression is certainly a common mechanism,we have encountered other mechanisms by which vitamins can regulate proteins.Provide one example of posttranslational modification,being as specific as possible.

7-dehydrocholesterol is the form of vitamin D that is added to fortify milk.

Inadequate vitamin D intake has been associated with autoimmune conditions such as rheumatoid arthritis,Crohn's disease,multiple sclerosis,and type I diabetes.

Match the factor to its correct action. -XIa

Match the factor to its correct action. -Xa

Subclinical vitamin K deficiency may be associated with diminished bone mineral density and increased fracture rates.

Indicate: (1)the active form of vitamin K, (2)the general function of vitamin K,and (3)an example of the general function (this could be a specific reaction or simply indicate a pathway/ process where it occurs).Your answers do not need to be long!

Match each vitamer with its function. -11-cis retinal

Match the factor to its correct action. -XIIIa

A good source of vitamin D is milk,because it is fortified with 1,25-(OH)₂-vitamin D₃.

Match each vitamer with its function. -retinoic acid

Match the factor to its correct action. -VII

Match each vitamer with its function. -alpha-tocopherol

Match the factor to its correct action. -VIIa

Vitamin A enhances vitamin K absorption and increases the plasma concentration of vitamin E.

Match each vitamer with its function. -calcitriol

Match each vitamer with its function. -hydroquinone (KH₂)

Explain the process by which rhodopsin is formed.