Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

G.Parslows Learning Objectives > Endocrine biochem > Flashcards

Endocrine biochem Flashcards

1
Q

Iodine is an element commonly found in high abundance in which areas?

A

in the sea

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

What is the RDI for iodine

A

150ug

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

What is TRH? where is it released from?

A

Thyrotropin releasing hormone - released from the hypothalamus

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

What is cretinism? what is it caused by?

A

A congenital condition caused by maternal iodine deficiency, worlds most common form of mental retardation and growth retardation

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

Radiation from I (-131) can be used to what?

A

destroy the thyroid

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

What kind of receptors do thyroid hormones operate via?

A

membrane receptors and cause direct activation of genes in DNA

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

What is the atomic number of iodine?

A

53

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

Where is cholesterol found in the body?

A

free in membranes and as esters in storage

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

Where are human steroids derived from?

A

dietary steroids or are made from acetyl-coA in the liver

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

Corticosteroids refers to which two groups of steroids?

A

Glucocorticoids (eg cortisol) and mineralocorticoids (aldosterone)

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

Where are oestrogen and progesterone made primarily

A

ovary and also placenta during pregnancy

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

Where is testosterone primarily produced?

A

testes

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

Tamoxifen blocks what steroid action?

A

blocks oestrogen receptors and is used in the treatment of breast cancer

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

What is the effect of leuprolide?

A

lowers testosterone - used in treatment of prostate cancers

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

What are the actions of anabolic steroids?

A

interact with androgen receptors to increase muscle and bone synthesis

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

Where does the name cholesterol originate from?

A

greek chole- (bile) and stereos (solid)

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

What is cholesterol?

A

a waxy steroid metabolites

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

What is cholesterols role in cell membranes?

A

required for proper membrane permeability and fluidity (makes membrane LESS fluid)

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

What is a lipoprotein? What is their function?

A

biochemical assembly that contains proteins and lipids. Carry cholesterol in the blood

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

What are some examples of lipoproteins?

A

chylomicrons, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and high density lipoprotein (HDL)

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

Arteriolosclerosis is promoted by excess levels of which lipoprotein?

A

LDL

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

What did Goldstein and Brown win a nobel prize for?

A

Identifying the LDL receptor on the liver which carries LDL and VLDL into the liver via receptor mediated endocytosis - this process is essential for feedback inhibition of HMG-CoA Reductase, muatations in this receptor lead to familial hypercholesterolaemia

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

Apart from its role in cell membranes what other roles (3) does cholesterol have?

A
  1. precursor to steroid hormones such as testosterone, cortisol, aldosterone, 2. component of bile salts 3. Vit D production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how many carbons does cholesterol have?

A

27

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How many more times energy does NADPH have compared to ATP
7 times more
26
Where are human steroids derived from?
Cholesterol -> dietary or made in the liver from Acetyl-CoA
27
What is the most abundant steroid in the body?
cholesterol
28
Where is oestrogen and progesterone made?
Ovary and placenta
29
How are steroids eliminated?
by CYP3A4 in the liver endoplasmic reticulum which adds a OH group
30
What is Cyproterone acetate? what is it used for?
Inhibitor of the andreogen receptor. Used to treat Hirsuitism in females, male-to female gender change, prostate cancer, benign prostatic hyperplasia, priapism and hypersexuality (chemical castration)
31
What protein does cortisol bind in the blood?
transcortin
32
Hb makes up what percentage of RBC dry content?
97%
33
carbon dioxide can bind to Hb and form what? what proportion of the total respiratory CO2 is in this form?
forms carbaminohaemoglobin | 15% of total
34
Hb carries nitric oxide bound to what molecule on globin?
thiol group of globin
35
Why does Hb carry nitric oxide?
releases it at the same time as oxygen to relax vascular walls and enhance gas diffusion
36
Kendrew and Perutz one a nobel price for doing what regarding Hb?
solving its protein structure (the first protein structure solved)
37
What is the structural difference between adult and foetal Hb?
Foetal: alpha2-gamma2 Adult:alpha2-beta2
38
Mutations in amino acid sequences cause hundred of whats (in relation to Hb)?
haemaglobinopathies
39
What was Christian Bohrs contributed to our knowledge about Hb?
described the sigmoid binding character of Hb-O2
40
What is the structure of haemaglobin?
Tetramer of globin subunits (proteins) with 4 haem groups inserted into each
41
What colour is Hb-CO?
bright red
42
What colour is De-oxy Hb?
dark red
43
What colour is HbO2?
scarlet red
44
What binds better to Hb O2 of CO?
CO binds 200x better than O2
45
What is Met Hb?
Hb with Fe3+ in the haem due to oxidation = found in aged RBCs
46
Haem inserts into the globin via a locking mechanism involving binding of histidine residues F8 and E7. One is always bound whilst the other can be displaced - which is which?
F8 is always locked (think its FATE for globin and haem to be together) E7 can be displaced by O2, CO and cyanide
47
What is the role of Bisphosphoglycerate (BPG)
stabilises Deoxy-Hb via 8 salt bonds which makes this form rigid (tense) and stops Oxygen binding back to Hb in the tissues. It is displaced when O2 levels are high (in the lungs)
48
Oxygen binding to Hb shows cooperativity - what does this mean?
When the first Oxygen binds to Hb it induces a change in the quaternary structure of Hb which changes the affinity of the other Oxygen binding sites - this means with only small increases in the concentration of O2 it is much easier to saturate the rest of the Hb molecule
49
What happens to the Hb-Oxygen binding curve in the presence of acid (bohr effect)? What functionally is the relevance of this?
graph is shifted to the right- meaning Hb has LESS affinity for O2, the relevance of this is that working tissues produce lactic acid and they require more O2 so we want the DeOxy-Hb form to be more stabilized so more oxygen is given up in the tissues - this is achieved via bonding to histidine residues
50
How does altitude alter the Oxygen-Hb binding curve? how is this achieved?
shifts it to the right -> giving more O2 to the tissues compensates for less O2 being picked up in the lungs. At altitude RBCs produce more BPG
51
Why does foetal Hb have higher affinity for O2 than adult hb?
gamma subunits have 6 positive charges (not 8) so BPG is bound less avidly so deoxy-form is stabilised less
52
What was Archibald Garrods field of study?
inborn errors of metabolism
53
The major burden of pathology in australia from genetic diseases is due to what disease?
Cystic Fibrosis
54
________was the first disease to be routinely tested for at birth and treated as required
phenylketonuria (PKU)
55
Genetic testing is usually carried out using what technique?
PCR
56
What is the most common x-linked recessive disorder? give some other examples
red-green colour blindess is the most common, others are haemophilia Am duchenne muscular dystrophy, Lesch-Nyhan syndrome
57
What happens in children affected by PKU?
they lack phenylalanine hydroxylase leading to a build up of Phe which gets converted to phenylpyruvate (a ketone) which damages the brain and affects melanin synthesis
58
What is the incidence of CF in australia?
in in 2500 births
59
What is the carrier rate of the CF gene in Australia?
1 in 25
60
What is the most common CF mutation?
Delta F506 in the CFTR protein (chloride channel)
61
What is Ehlers Danlos syndrome?
Inherited connective tissue disoder - mostly autosomal dominant condition due to mutations in genes that encode the structure, production or processing of COLLAGEN or proteins that interact with collagen -> those affected have hypermobile joints, hyper-elasticity of the skin but also affects arteries.
62
What is Marfan Syndrome?
mutation in fibrillin gene leading to bone overgrowth and joint laxity, with disproportionately long extremities compared to the size of the trunk
63
What enzyme is important in melanin formation?
tyrosinase
64
Is the inheritance of skin colour mono or polygenetic?
polygenetic -> 40 genes influence skin colour
65
If you lack tyrosinase what colour is your skin?
NO melanin = albinism

G.Parslows Learning Objectives (1 decks)

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