Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CMBM exam 3 > Nutrients, Oxidation and Antioxidants > Flashcards

Nutrients, Oxidation and Antioxidants Flashcards

(85 cards)

Start Studying
1
Q

Is vitamin E water or lipid soluble?

A

Lipid soluble

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

Is vitamin C water or lipid soluble?

A

Water soluble

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

What is oxidative stress?

A

O2 will steal an electron from a reduced metal, flavin etc and become superoxide) O2-

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

Superoxide and its products are known as;

A

Reactive Oxygen Species or ROS

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

The gas hormone nitric oxide (NO) is known as a;

A

Reactive Nitrogen Species (RNS)

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

How are ROS and RNS formed?

A

By accident in the electron transport chain

On purpose by immune cells

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

What can have its structure modified by oxidative or nitrosative stress?

A

Proteins, lipids, carbohydrates, individual nucleotide bases

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

Is it good or bad that a hydroxyl group can react with anything around it?

A

Bad

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

What can aldehydes do that are considered bad?

A

Create cross links between proteins

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

How is iron important?

A

Key role in many enzymes (cytochromes)

Catalysis and electron transfer, oxygen transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is iron toxic?

A

It is insoluble in presence of oxygen
Catalyzes the Haber-Weiss-Fenton Reactions
Produces a free radical hydroxyl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does iron help defend against the toxins it makes?

A

With Superoxide dismutase to aid in conversion of superoxide to more stable form

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

Where and how is iron stored?

A

In ferritin and hemosiderin mostly in the liver

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

What molecule moves iron from various organs and cells into tissues and bones?

A

Transferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How much iron should a person have in a day to maintain stores?

A

At least 8 mg

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

How is the transferrin receptor complex internalized?

A

By receptor medicated endocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is iron release?

A

By acidification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is non-heme iron uptake inhibited?

A

By phytate and polyphenols in common food (plant sources) like;
- black tea
- cocoa
- chamomile
Polyphenols numerous rings chelate the iron increasing its elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is iron uptake stimulated?

A

Vitamin C
Organic acids
Heme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a hereditary excess in iron called?

A

Hemochromatosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a dietary overload of iron called and how can someone get it?

A

Hemosiderosis

Alcohol (red wines) and over using supplements (children)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What drugs does iron decrease the absorption of?

A

Thyroxine, tetracyclin, ciprofaloxacin
occurs because numerous rings on the molecules act as chelators and this more effectively eliminates the drug and iron along with it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is anemia?

A

Abnormally low blood hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What enzymes can protect you from reactive oxygen species?

A

Superoxidase dismutases
Catalases
Peroxidases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What chemicals can protect you from ROS?
Bilirubin, glutathione, catalase, vitamin E, B-carotene and ascorbate (vit C)
26
What is glutathione?
A small tripeptide reversibly oxidized/reduced and can be regenerated by NADPH and glutathione reductase
27
Superoxide Dismutase
catalyzes superoxide to hydrogen peroxide
28
What is the danger in an ischemic/reperfusion injury?
the initial return of oxygen creates a burst of ROS species
29
Reactive Nitrogen species -RNS
NO | Peroxynitrite is ONOO- which is O2- + NO
30
Although H2O2 is not a free radical but ...
it can generate free radicals by encountering a transition metal
31
Lipid degradation generates
Peroxyl radicals
32
HOCl
produced by neutrophils during respiratory burst
33
Peroxynitrite
RNOS strong oxidizing agent that is not a free radical can generate NO2 which is a radical
34
what AA is important because it can be reversibly oxidized and reduced?
Methionine | this requires a reduced thiol such as glutathione
35
why are aldehydes so detrimental?
they crosslink proteins preventing them from functioning and making the breakdown and elimination difficult
36
What is Vit E's role in lipid oxidation ?
it prevents propagation of damage by acting as a sponge
37
Influx of intracellular calcium causes?
cellular death through activation of numerous intracellular pathways
38
what complicates the monitoring of oxidative damage in the vascular system?
oxidative damage not necessarily reflected by biomarkers and cannot be used as therapeutic targets damage build ups in the subendothelial space
39
Haber Weiss Fenton reaction
(1) Fe+2 + O2 -> Fe+3 + O2*- (2) 2 O2*- + 2H+ --> H2O2 + O2 (3) Fe+2 + H2O2 --> OH* + OH- + Fe+3
40
What transition metal in non reactive in biosystems?
Zinc
41
In regards to reduction potential, the more negative it is ....
the more likely it will GIVE UP electrons
42
What aids Iron absorption?
Vit C by acting as an electron donor converting Fe+3 to Fe+2 which is more soluble
43
In general, what effects metal solubility?
very insoluble at pH 7 | but most are very soluble in acid
44
Freidreich ataxia
hereditary ataxia | defective frataxin - Fe cant be exported from Mitochondria and iron builds up in the nervous system
45
What metal is required for Iron absorption?
Cu
46
What can Fe deficiency lead to ?
lead poisoning because DMT/Divalent metal transporter expression is increased and it nonspecifically uptakes other metals as well
47
What molecules act as buffers to maintain electrical potentials in cells?
NAD(P), glutathione and Ascorbate all these uptake electrons at different ranges to cover a wide range of redox potentials to maintain the electrical balance in cells similar to how pH is maintained in the blood
48
How was it determined that Vitamin E was a requirement in the human body?
Patients with fat malabsoprtion syndromes were shown to have low levels of vitamin E
49
What sequesters Fe and Cu ions which prevents ROS?
Ceroplasmin (Cu), albumin (metals) and transferrin
50
What is Vitamin E actually?
A collection of molecules which function like alpha-tocopherol (alpha, beta, gamma, delta)
51
What is the main function of vit E?
Antioxidant Stops propagation of free-radical damage in membranes May prevent fatty acid damage in membranes
52
Tocopheryl esters (a form of vit E) are broken up by;
Pancreatic esterases (which also break up fatty acids)
53
What is essential for vit E absorption?
Bile acids Deficiency occurs in fat malabsorption which makes sense since Vit E is fat soluble
54
True or False | Like other fat soluble vitamins, E accumulates in toxic levels.
False
55
What uptakes vit E?
Chylomicrons
56
How is vit E oxidized and excreted?
Omega-oxidation by cytochrome P450 | Removed in urine or bile
57
What large organ is also important for vit E excretion?
Skin - sebaceous glands
58
If there is a deficiency in vit E what are some diagnosis that can develop?
Retintis pigmentosa, neurological symptoms
59
There is only one type of organism that can make vit E, what is it?
Plants | Best sources are veggie oils
60
If you are deficient in alpha-tocopherol symptoms of ____ are mimicked.
Freidreich's ataxia
61
What can regenerate reduced vit E?
Vitamin C
62
What is vit C's main function?
Collegen biosynthesis converts Proline to hydroxyproline converts Lysine to hydroxylysine for crosslinking
63
L-ascorbic acid is derived from ____.
D-glucuronate | structure similar to glucose, can be uptaken by GLUT4
64
How many electrons can vit C donate? What does it use to regenerate?
2 | NAD(P)H or glutathione
65
What is a deficiency in vit C called?
Scurvy
66
What are some symptoms of scurvy?
Connective tissue weakness, vascular damage, hemorrhagia, bleeding gums, poor wound and bone healing
67
What happens if there is excess vit C?
Hypoglycemia (blocks glucose uptake), kidney stones, indigestion, dissolves tooth enamel No direct evidence that megadose helps colds or flu
68
What organ needs the most vit C?
pituitary gland | maybe cause its highly sensitive oxidative damage?
69
Do vitamins C and E aid in primary prevention of total cancer incidence or mortality?
No
70
In women with cardiovascular event who have high risk CVD, does ascorbic acid, vit E or beta carotene protect against it?
No
71
Do vit C and E help prevent prostate cancer?
No
72
Does vitamin C decrease the risk of diabetes?
Yes
73
Does multivitamin supplementation prevent cancer or CVD?
Perhaps, very limited evidence
74
what chemicals absorb electrons?
bilirubin, glutathione, ascorbate (vit c)
75
Glutathione is a small tripeptide composed of ...
glutamate, cysteine and glycine
76
what contributes to Glutathione's reversibly oxidation/reduction ability?
it is a sulfhydryl, the sulfur atoms can easily lose electrons or be partially ionized it can also be nitrosylated
77
What state is the glutathione pool maintained in ?
Reduced state (SH) | S-S) is the oxidized state (from 4 to 2 electrons
78
What are the defenses in the blood/plasma against reactive oxygen species?
Vitamin C Bilirubin uric acid
79
why can't an anemic (low heme) pt be given IV heme?
Free Heme in the body is actually toxic | Its is normally bound to Haptoglobin or Hemopexin in the blood. The molecules clean up heme from lysed RBCs
80
LDLs contain a significant amount of ?
Vitamin E which helps to protect them oxidation
81
what improves bioavailability of Vit E?
the fat content of food | 2 times more available when taken with milk vs. OJ
82
Can vitamin E be stored?
yes in Adipose tissue
83
What else is Vit C involved in?
synthesis of adrenal hormones drug metabolism folate metabolism stimulates iron uptake
84
what patients should consider taking nutrient supplements?
older adults pregnant women pt who are food insecure alcohol dependent strict vegetarians and vegans (for these ppl when genetics may affect nutrition) those on drug regimens that alter metabolism/excretion
85
A common measure of oxidative stress in plasma?
Malondialdehyde

CMBM exam 3 (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions