Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biosai 106 > nutrition > Flashcards

nutrition Flashcards

1
Q

macronutrients

A

carbohydrates, fats, proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

micronutrients

A

vitamins and minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why are vitamins “essential”

A

because they are compounds which are necessary but the human body cannot synthesise them, therefore they must be obtained from a nutrient source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

large amounts of vitamins are required to have an effect true/false

A

FALSE small amounts only (

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

vitamins are building blocks for larger molecules true false

A

false false false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

vitamins do not yield energy when broken down true false

A

true true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how many vitamins are required in the human diet

A

12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

vitamin C and B are…

A

water soluble vitamins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

vitamin A E D and K are…

A

lipid-soluble vitamins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

features of water soluble vitamins

A
  • functional uniformity
  • highly variable structures
  • carry mobile metabolic groups
  • all require modification (except for vitamin C)
  • readily excreted by the kidneys
  • labile (degradable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lipid soluble vitamins

A
  • structural uniformity
  • functionally diverse
  • not as readily absorbed/extracted from food
  • generally not coenzymes/ activated carriers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

vitamin A and D

A

act like hormones. toxic in excess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why can’t humans synthesise vitamin C?

A

we don’t have the enzyme GULOLACTONE OXIDASE. the gene is present, but mutations have made it inactive. theory: the same enzyme synthesises H2O2 which is toxic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

three B vitamins to remember

A 
Riboflavin (B2)
Nicotinic acid (B3)
Folic acid (B9)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

vitamin c also called…

A

ascorbate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

features of vitamin C

A
  • electron donor (reducing agent / antioxidant) for 8 enzymes
  • interacts with enzymes having monooxygenase or dioxygenase activity
  • accelerates hydroxylation (3 enzymes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

vitamin c deficiency

A

scurvy

18
Q

vitamin D deficiency

A

bone issue (rickets, osteomalacia)

19
Q

causes of vitamin C deficiency

A
  • sailors
  • elderly
  • alcoholics (decreased absorption and storage)
  • mentally ill
  • otago uni scrubs
20
Q

amino acids making up collagen

A

every third residue = Glysine

proline and HYDROXYPROLINE are also abundant

21
Q

why is vitamin C necessary for collagen synthesis

A
  • stabilisation of the triple helix (of collagen) requires HYDROXYPROLINE
  • HYDROXYPROLINE requires vitamin c for synthesis
  • Vitamin C reduces ferric (Fe3+) to ferrous (Fe2+)
  • ferrous activates proline hydroxylase
  • hydroxylase converts proline to hydroxyproline
22
Q

sources of 1 carbon units

A

Serine
formate
glycine
histidine

23
Q

end products of 1 carbon metabolism

A

methianine
eTMP
purines

24
Q

1 carbon units

A

methyl
methylene
formyl

25
Q

what are folates essential for?

A

cell growth and tissue development

26
Q

three major structural components of folic acid

A
  1. bicyclic, heterocyclic, pteridine ring
  2. benzoic acid (P-amino) PABA
  3. Glutamic acid (folic acid = monoglutamic)
27
Q

folate to dihydrofolate to tetrahydrofolate, catalysed by…

A

dihydrofolate reductase. This is in mammals.

28
Q

antimetabolite =

A

synthetic compound, usually structurally-related to the metabolite, that interferes with the metabolite to which it is related

29
Q

how are poly-γ-glutamate tails added to tetrahydrofolate

A

addition of multiple glutamic acid residues in liver cells

30
Q

where are tetrahydrofolates largely stored

A

liver

31
Q

why are poly-γ-glutamate tails added?

A

i. helps retain THF inside cells, because it is a poor substrate for anion transporter
ii. helps THF bind more tightly to enzymes - enhanced affinity

32
Q

what is the role of folate/tetrahydrofolate derivatives?

A

to transfer 1C units to N5 and N10 in THF

33
Q

carbon unit transfer is involved in… which are all important for…

A

synthesis of amino acids, purines, deoxythymine monophosphate
all building blocks for RNA/DNA precursors

34
Q

inhibitors of folate synthesis inhibit… resulting in…

A

DHFR e.g. Aminopterin binds DHFR at least 1000 fold higher affinity.
By blocking DHFR you will stop Production of DNA precursors.
= STOP GROWTH

35
Q

inhibitors of bacterial cell growth. What are they called and what do they do, etc. ?????

A

–BACTERIOSTATIC drugs–
e.g. methotrexate - sulphonamides
inhibit enzyme: DIHYDROPTEROATE

36
Q

neural tube defects

A

combination of genetic predisposition & environmental (deficient folate).
= Failure of neural tube to close

37
Q

spina bifida

A

neural tube doesn’t close at the caudal end

38
Q

anencephaly

A

neural tube doesn’t close at the cranial end. No cerebral cortex.

39
Q

how does folate prevent neural tube defects?

A

increased methylation of various important molecules

40
Q

summary :
enzyme involved with folate in bacteria _______________
enzyme involved in mammals ______________

A

summary :
enzyme involved with folate in bacteria dihydropteroate synthase
enzyme involved in mammals dihydrofolate reductase

Biosai 106 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions