Vitamins Flashcards Preview

Biomolecules of Life > Vitamins > Flashcards

Flashcards in Vitamins Deck (183)
Loading flashcards...
1

What is a vitamin and in what amounts are they needed?

Vitamins are essential organic substances needed in minute amounts to activate highly specific metabolic functions in the body

2

Why are vitamins accessory nutrients?

Because they themselves supply no energy and form no structures but their deficiencies can be dangerous as well as toxic if some are in excess

3

What are vitamins that must be consumed called?

Preformed vitamins

4

What are vitamins that may be synthesised by the body using precursors called?

Pro-vitamins

5

Vitamins can be classified, what are the two sub divisions?

Water soluble vitamins and lipid soluble vitamins

6

How would you describe water soluble vitamins?

They are not stored in any tissues and excess is removed in urine

7

Examples of some water soluble vitamins would include?

b1, b2, b3, b5, b6, b9, b12, vitamin c, biotin (vit h)

8

Where are lipid soluble vitamins stored and can they be removed?

They are stored in the liver and adipose. The body has no way of removing them until they are used.

9

Give some examples of some lipid soluble vitamins

Vitamins a, d, e and k

10

Of the vitamins that are ingested, where do the majority originate from?

From plant sources (except b12) as byproducts of photosynthesis

11

Give two examples of pro vitamins and from what they are synthesised

carotene --> vitamin a ultraviolet light --> vitamin d

12

What are most vitamins converted into, for use inside the body? What is one of their main roles?

Most vitamins are converted into coenzymes - b12

13

Some vitamins such as vitamin d and some metabolites of vitamin a have a different role other than coenzymes, what can they do?

They act more like hormones, binding to receptors and controlling gene expression and metabolism

14

Some vitamins such as vit c and vit e act as ______, not as coenzymes or the control of gene expression and metabolism

antioxidants

15

What is the role of antioxidants

Preventing or delaying some types of cell damage

16

What is a coenzyme?

A coenzyme is a non protein compound that is necessary for the functioning of an enzyme

17

Some coenzymes allow the substrate to react more readily, give some vitamin derivatives that allow this

CoA, pyridoxal phosphate, thiamin diphosphate and vitamin b12

18

There are some oxidative coenzymes, what are these

NAD+, NADP+, FAD, lipoic acid

19

What is the function of oxidative coenzymes?

To carry hydrogen atoms or electrons

20

What is the protein part of the enzyme called?

The apoenzyme

21

When the protein part of the enzyme is in combination with the coenzyme the catalytically competent enzyme is known as what?

As the holoenzyme

22

Apoenzyme + coenzyme =

holoenzyme

23

Vitamin b1 is

thiamine

24

vitamin b2 is

riboflavin

25

vitamin b3 is

niacin

26

vitamin b5 is

pantothenic acid

27

vitamin b6 is

pyridoxine

28

vitamin b9 is

folic acid

29

vitamin b12 is

cobalamin

30

vitamin c is

ascorbic acid