Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Urea Cycle > Flashcards

Urea Cycle Flashcards

1
Q

Transamination

A

process for removing nitrogen from amino acids, tissues can use the carbon skeleton of the aa as fuel and transport the nitrogen to the liver for conversion into urea

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

Where is nitrogen converted into urea?

A

in the liver

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

PLP (pyridoxal phosphate)

A

coenzyme, active form of vitamin B6

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

urea formation

A

proteins -> amino acids -> NH2 removed -> forms ammonia, liver converts to urea

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

Deamination

A

the removal of an amino group from an organism, particularly from an amino acid

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

during fast what will be broken down to produce energy?

A

muscle protein

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

the break down of muscle protein causes the generation of what?

A

nitrogenous waste

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

urea will be excreted through ….

A

urine

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

healthy adults are in nitrogen balance, which means.

A

amount of nitrogen taken in = amount of nitrogen excreted (mostly through urea)

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

the properly functioning liver has a great capacity for what?

A

forming urea

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

The greater the amount of ammonia produced =

A

The greater amount of urea converted

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

high levels of ammonia indicates a problem with what organ?

A

The liver

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

ammonia =

A

liver

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

urea =

A

kidney

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

urea will be secreted from what organ?

A

The kidneys

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

Reactive Oxygen Species (ROS)

A

due to oxygen having 2 single electrons in 2 different orbitals, both with the same spin, it is a biradical

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

2 electrons with the same spin cannot …..

A

easily oxidize the bonds in organic compounds because of “spin restriction” - enzyme is required

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

ROS are generated

A

naturally by cellular process

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

free radicals

A

those that can exist independently, can take other electrons from other compounds (usually H’s)

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

radicals formed in enzymatic reactions

A

intermediates that form stable’s products and do not go “free”

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

what will ROS initiate?

A

chain reactions that damage substances within the cell

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

Sources of ROS

A
  1. Mitochondrial electron transport chain produces ATP to run cellular processes, but accidentally forms superoxide
  2. Ionizing radiation (X-rays, radioactive chemicals)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cytochrome P450 enzymes

A

metabolizes drugs, alcohol, and chemical toxins

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

job of cytochrome P450 enzymes

A

oxidize the drugs and other substrates to make them more soluble for excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Radical intermediates of Cytochrome P450 can

A

escape and become free radicals, causing cell damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What damage can be caused by ROS

A
  • Protein damage
  • Mitochondrial damage
  • Membrane damage
  • DNA damage
  • Cell swelling
  • Increased Permeability
  • Massive influx of CA2+
  • Lipid Per-oxidation
  • Respiratory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

DNA damage due to ROS

A

strand breaks or 1/20 different alterations that can lead to mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Is there anything that can help repair the DNA damage done by the ROS?

A

If the DNA repair systems can fix the alterations than yes, if missed mutations will accumulate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Endogenous sources of ROS

A

Inside the body (O2, H2O2, OH, NO, O2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Reactive Nitrogen-Oxygen Species (RNOS)

A

free radicals that cause damage to cellular components: DNA, cell membranes, enzymes, electron-transport chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

RNOS compounds come from where?

A

Produced in the cell or can be from outside sources that will damage our cells

32
Q

Inflammation free radicals

A

destroy invading pathogen or clean up dead cells in damaged tissues, activated neutrophils

33
Q

Respiratory burst (oxidative burst)

A

occurs in activated neutrophils, consumes oxygen to create reactive substances that will kill phagocytosed bacteria

34
Q

Is inflammation helpful or harmful?

A

either. can lead to collateral damage to the surrounding tissues

35
Q

Cellular defences put in place to do what?

A

fights the effects of free radicals

36
Q

oxidative stress

A

a condition in which the production of oxidants and free radicals exceeds the body’s ability to handle them and prevent damage

37
Q

endogenous antioxidants (ex. superoxide dismutases (SOD)) and catalase

A

have different isoforms that exist in different parts of the cells

38
Q

glutatione peroxidase

A

function to remove peroxiding formed outside of peroxisomes

39
Q

metals found in nutrients in the diet

A

Cu, Zn, Mn, Fe, Se

40
Q

Fat soluble Vit E and Waters soluble Vit C are involved in

A

neutralizing free radicals

41
Q

Vit E

A

donate an electron to radicals

42
Q

Vit C

A

donate an electron to Vit E to regenerate its antioxidant capacity

43
Q

Aged-related macular degeneration (AMD) is

A

A disease that blurs central vision, oxidative damage thought to be responsible for advancing the disease

44
Q

Where does the urea cycle exclusively take place?

A

in the liver

45
Q

When does nitrogen occur?

A

at physiological pH in the form of NH4 and ammonium in the blood

46
Q

Is urea toxic to the body? what happens to it?

A

No it is sent to the kidney and excreted from there

47
Q

What happens to the protein that is broken down and not used for protein synthesis?

A

deaminated

48
Q

TOO much protein means

A
  • cannot store protein
  • always functional
  • we turn it into glucose or fat to store
49
Q

When we have more protein what happens?

A
  • turns into glucose

- restores glycogen and the rest is stored as fat packed in VLDL

50
Q

What must nitrogen be converted into to be excreted in the urine and where?

A

turned into urea in the liver

51
Q

How can essential amino acids be made?

A

transamination

52
Q

What is PLP involved in?

A

amino acid metabolism

53
Q

Great amount of ammonia produced means

A

greater amount converted to urea

54
Q

When we create nitrogen through deamination what else occurs?w

A

we create ammonia which is toxic to CNS

55
Q

What happens to the ammonia created from deamination?

A

the liver will take it to create urea and send it to kidney to be excreted

56
Q

Elevated ammonia means

A

liver problem; chronic alcohol abuse, enzymes, hepatitis

57
Q

Elevated urea means

A

made it through the urea cycle; kidneys might be at risk

58
Q

Where do most of the steps in converting urea locate?

A

cytosol

59
Q

What is the most common X linked issue within the urea cycle?

A

orithine transcarbamoylase

60
Q

What causes alot of chronic diseases? and what are they?

A

reactive oxygen species

- cancer, respiratory problems, heart disease

61
Q

How are ROS generated?

A

by natural processes; unfortunate

62
Q

Source of ROS

A

the mitochondrial electron transport chain produces ATP to run cellular processes but accidentally forms superoxide

63
Q

What is an effective way to prevent DNA mutation when ROS occur?

A

base excision repair system

64
Q

What are RNOS

A

Exogenous forms of ROS

65
Q

Where do RNOS occur from?

A

those who smoke, poor diet etc

66
Q

RNOS damage can go to cellular components such as

A

DNA, cell membrane, enzymes, the ETC etc

67
Q

Endogenous

A

within our body

68
Q

Exogenous and antioxidant

A

taken into our body

69
Q

What can help reduce ROS?

A

vegetables and fruits

70
Q

Superoxidase dismutase is what

A

an enzyme in a number of different forms within a number of different cells

71
Q

When there is more LDL and no antioxidants to neutralize them what occurs?

A

atherosclerosis

72
Q

What vitamins are involved in neutralizing free radicals?

A

Vitamin E and C

73
Q

What does vitamin E do?

A

donate electron to free radicals

74
Q

Vitamin C can?

A

donate electron to vitamin E to regenerate its antioxidant capacity

75
Q

Carotenoids

A

derived from the diet and are antioxidant as well

Biochemistry (22 decks)

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