Vitamins Part 1 Flashcards

Questions and Answers

What is a micronutrient?

Nutrient that is essential either vitamin or mineral.

How much is required of micronutrients?

mg or microg

What two vitamins are partially essential?

Vitamin D and niacin

What are most vitamins' main function?

Protein cofactors Signup and view all the answers

What are two categories of protein cofactors?

Mobile substrate and bound stable, can be covalent or non-covalent. Signup and view all the answers

Are all vitamins cofactors?

False Signup and view all the answers

What are the four basic functions of vitamins?

Carriers, catalysts, sensors, signals Signup and view all the answers

How are vitamins carriers?

Bind/release things; they do change the substrate they bind to. Signup and view all the answers

How are vitamins catalysts?

Bind and change the substrate. Signup and view all the answers

How are vitamins sensors?

Physically sense metabolism/environment conditions. Signup and view all the answers

How are vitamins signals?

Tell how far development is or a physiological state. Signup and view all the answers

Break down the word vitamin.

vita, amine Signup and view all the answers

What are vitamers?

Isomers of a vitamin. Signup and view all the answers

What was the first vitamin to be isolated?

Thiamin Signup and view all the answers

What is the old view of how to divide vitamins?

Fat soluble vs. water soluble. Signup and view all the answers

What are water-soluble vitamins?

All B vitamins and vitamin C. Signup and view all the answers

What are fat-soluble vitamins?

A, D, E, K. Signup and view all the answers

What is the new view of how to divide vitamins?

Based on function. Signup and view all the answers

What are the categories of vitamins based on function?

Energy metabolism B1-B6, Blood Function- K, folate, B12, Antioxidants- C/E, Signaling Molecule- A/D. Signup and view all the answers

What is B5 found as in FA synthase?

Phosphopantetheine Signup and view all the answers

What does B5 carry and what allows it to do this?

Acyl or acetyl groups; high energy thiol ester bonds. Signup and view all the answers

What are all the enzymes that use CoA?

Pyruvate DHD, alpha KG DHD, alpha KB DHD, FA Beta-Ox, FA Synthase. Signup and view all the answers

Where is B5 found on fatty acid synthase?

Two different domains of enzyme: acyl carrier and condensing enzyme, found as phospho. Signup and view all the answers

Is deficiency of B5 common?

False Signup and view all the answers

When are cases of B5 deficiency found?

Alcoholism and severe malnourishment. Signup and view all the answers

What symptoms are associated with B5 deficiency?

Burning feet and neurodegeneration. Signup and view all the answers

How is B5 absorbed and digested?

All forms of B5 are turned into pantothenate and absorbed with active transport mechanism. Signup and view all the answers

How does B5 circulate?

Circulates as pantothenate and turned into CoA in peripheral tissue. Signup and view all the answers

What law regulates supplements?

Dietary Supplement Health/Education Act-1994. Signup and view all the answers

What claims can you make with supplements?

Cannot claim products treat, cure, or prevent disease but you can make misleading claims. Signup and view all the answers

What does EAR stand for?

Meets requirements of half the population. Signup and view all the answers

What does RDA stand for?

Recommended Daily Allowance. Signup and view all the answers

What does AI stand for?

Adequate Intake. Signup and view all the answers

What does UI stand for?

Upper Intake Level. Signup and view all the answers

What are ways to directly measure nutrient intake?

Blood, hair, nails. Signup and view all the answers

What are ways to measure homeostasis?

Urinary excretion, partition bolus, tracer, input/excretion. Signup and view all the answers

What indicates indirect measure of physiological action?

Excretion of metabolism/blood clotting. Signup and view all the answers

Study Notes

Micronutrients Overview

Micronutrients are essential nutrients that include vitamins and minerals.
Required in small amounts, measured in milligrams (mg) or micrograms (µg).

Essential Vitamins

Vitamin D and niacin are partially essential vitamins.
Most vitamins function as protein cofactors.

Protein Cofactors

Two categories:
- Mobile substrates: transient in function.
- Bound stable: can be covalent or non-covalent connections to proteins.

Vitamin Functions

Four basic functions of vitamins:
- Carriers: bind and release substrates, altering them.
- Catalysts: bind and modify substrates.
- Sensors: detect metabolic/environmental changes.
- Signals: indicate developmental progress or physiological states.

Etymology of Vitamin

"Vita" means life in Latin.
"Amine" refers to the first vitamin with an amine group.

Vitamers

Vitamers are isomers of a vitamin that may have different biological activities.

History of Vitamins

Significant studies such as the Single Grain Experiment on cow diets showed varying effects on weight gain.
Corn was found to have the greatest impact on calf weight gain.

Vitamin Isolation

Thiamin was the first vitamin to be isolated.
Vitamins previously classified into fat-soluble (A, D, E, K) and water-soluble (B vitamins, C).

Modern Classification of Vitamins

Current division categorizes vitamins based on function:
- Energy metabolism: B1-B6
- Blood function: K, folate, B12
- Antioxidants: C and E
- Signaling molecules: A and D

Pantothenate (B5)

Acts as an enzyme cofactor, part of Coenzyme A and fatty acid synthase.
Exists as phosphopantetheine in fatty acid synthase, carrying acyl or acetyl groups through high-energy thiol ester bonds.

Enzymatic Roles of B5

Plays a role in multiple enzymes, including:
- Pyruvate dehydrogenase
- Alpha-ketoglutarate dehydrogenase
- Fatty acid beta-oxidation
- Fatty acid synthase

B5 Deficiency

Rare due to widespread food availability.
Notable cases may occur in those with alcoholism or severe malnutrition.
Symptoms include burning feet and neurodegeneration.

Absorption and Circulation of B5

All forms convert to pantothenate during digestion and are absorbed via active transport.
Circulates as pantothenate, converting to CoA in peripheral tissues.

Dietary Supplement Regulations

Regulated by the Dietary Supplement Health and Education Act of 1994.
Claims cannot state that products treat or prevent disease but can be misleading.

Nutrient Intake Measurements

EAR meets requirements of half the population.
RDA: Recommended Daily Allowance, based on EAR plus 2 standard deviations.
AI: Adequate Intake, recommended when no EAR exists.
UI: Upper Intake Level indicates potential for toxicity.

Testing Nutrient Intake

Measurement methods include:
- Direct: blood, hair, nails.
- Homeostasis: urinary excretion, tracer methods.
- Physiological action: monitoring metabolism or blood clotting.

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Description

Test your knowledge of essential micronutrients with these flashcards covering key concepts related to vitamins and minerals. This quiz will help you understand the basic definitions, required amounts, and the functions of different vitamins. Perfect for students looking to reinforce their understanding of nutrition concepts.