Brainscape's Knowledge GenomeTM

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


See full index

Blood cells- OB/Biochem > Plasma Proteins > Flashcards

Plasma Proteins Flashcards

1
Q

albumin definition

A

a family of globular proteins, most of which are the serum albumins commonly found in blood plasma

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

what is the most abundant blood plasma protein? + percentage

A

serum albumin- 50%

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

reference range

A

30-50g/L

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

charge at body pH

A

-17

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

plasma half life

A

20 days

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

albumin functions

A

carrier protein for steroids, fatty acids and T4 in the blood

stabilise extracellular fluid volume by contributing to oncotic pressure

transports hemin and bilirubin

binds to drugs

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

oncotic pressure definition

A

form of osmotic pressure induced by proteins in a blood vessel’s plasma that displaces water molecules, thus creating a relative water molecule deficit with water molecules moving back into the circulatory system within the lower venous pressure ends of capillaries

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

What can hypoalbuminemia cause? + explained

A

low albumin in blood, due to a decreased production in the liver, increased loss in gastrointestinal tract or kidneys, increased use in body

leads to abnormal distributions of fluid within the body- low oncotic pressure, too much fluid leaves blood

leads to oedema in lower legs, ascites in the abdomen and effusions around internal organs

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

ascites definition

A

abnormal build up of fluid in the abdomen

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

what are the oedemas and ascites symptoms of? + why?

A

severe chronic liver disease

serum albumin is produced by the liver, so if the liver is damaged less albumin is produced

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

How many molecules can the albumin carry?

A

one hemin and 6 long chain fatty acids can bind to serum albumin at the same time

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

name of another transport protein

A

transferrin

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

transferrin definition

A

iron binding blood plasma glycoproteins that control the level of free iron in biological fluids

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

what produces transferrin?

A

the liver

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

transferrin concentration in blood plasma

A

2.5g/L

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

Transferrin functions

A

binds iron in the form of Fe3+ ions tightly but reversibly in the duodenum, then carries it in the blood to then give to cells

when a transferrin protein loaded with iron encounters a transferrin receptor on the surface of a cell, it binds to it and is transported into the cell in a vesicle by receptor mediated endocytosis

transports iron in vivo from the duodenum and macrophages to the liver

iron bound albumin is internalised via clatrin coated pits

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

What hormone maintains iron homeostasis?

A

hepcidin

18
Q

Hepcidin function

A

regulates iron metabolism which leads to a decrease in blood iron concentration

inhibits iron transport by binding to the iron export channel ferroportin located on the basolateral surface of gut enterocytes and macrophages, preventing the iron from being absorbed by the blood from the gut

prevents the iron exportation and sequestration in cells

reduces dietary iron absorption

19
Q

where is hepcidin produced?

A

hepatocytes

20
Q

how is iron lost from the body?

A

menstruation in women

cell shedding from gut and skin

21
Q

consequences of iron deficiency

A

can lead to iron-deficiency anemia, where there are inadequate concentrations of functioning haemoglobin

22
Q

iron functions

A

form iron-surfer clusters needed in oxidative phosphorylation

form haemoglobin

23
Q

What are vitamin-K dependent clotting factors?

A

proteases, that once activated, act on each other sequentially

24
Q

What does the liver produce that inhibits them?

A

alpha-1 antitrypsin

25
Q

what is alpha-1-antitrypsin?

A

a protease inhibitor, a serpin, that binds covalently to enzymes which changes their conformation, thus inactivating them

26
Q

Another function of alpha-1 antitrypsin

A

helps protect tissues from enzymes of inflammatory cells, such as neutrophil elastase.

27
Q

what happens in alpha-1 antitrypsin deficiency?

A

neutrophil elastase is excessively free to break down elastin present in the lungs.

This degrades the elasticity of the lungs which can lead to chronic obstructive pulmonary disease

28
Q

what is ferritin?

A

universal intracellular protein that stores iron and releases its contents in a controlled fashion

acts as a buffer against iron deficiency and iron overload

29
Q

Lipoprotein definition

A

a biochemical assembly whose primary purpose is to transport hydrophobic lipid molecules in water, as in blood plasma or extracellular fluids

30
Q

lipoprotein structures

A

single layer phospholipid and cholesterols outer shell, with hydrophilic portions orientated outward toward the surrounding water and lipophilic portions within the particle

apolipoproteins are embedded in the outer shell to stabilise the complex and give functional identity

31
Q

stages of exogenous pathway

A

lipoprotein particle metabolism of dietary lipids

  1. bile emulsifies fats
  2. pancreatic lipase cleaves triacylglycerol molecule into two fatty acids and one monoacylglycerol
  3. enterocytes absorb the small molecules
  4. within the enterocytes, the molecules react again to form triacylglycerides
  5. lipids are then assembled with apoplipoprotein B-48 to form nascent chylomicrons
  6. chylomicrons then secreted into lacteals
  7. chylomicrons circulate in lymphatic vessels and are drained via the thoracic duct into the bloodstream
  8. chylomicrons then receive apoplipoproteins E and C-II from HDL, forming mature chylomicrons
  9. the mature chylomicrons activate lipoprotein lipase, which releases glycerol and fatty acids from the chylomicron, which can then be absorbed by peripheral tissues, especially adipose and muscle, for use as energy and storage
32
Q

stages of endogenous pathway

A

lipoprotein particle metabolism, where the lipids originate in the liver. Hepatocytes produce the triacylglycerols via de novo synthesis

  1. in the hepatocytes, triacylglycerols and cholesterol esters are assembled with apolipoprotein B-100 to form nascent VLDL particles
  2. the nascent VLDL particles are released into the blood stream via a process that depends upon apoliporotein B-100
  3. the VLDL particles bump into HDL particles, which donate apoplipoprotein C-II and E, converting it into a mature VLDL
  4. VLDL particles circulate and encounter lipoprotein lipase expressed on endothelial cells
  5. apolipoprotein C-II activates the enzyme and causes the hydrolysis of VLDL particle and release of glycerol and fatty acid
  6. molecules are then absorbed by peripheral tissues
33
Q

How is LDL produced?

A
  1. The hydrolysis of VLDL leaves VLDL remnants that circulate
  2. they interact with apoplipoprotein E and a remnant receptor, which enables them to be absorbed by the liver
  3. the particle is then broken down further by hepatic lipase which releases glycerol and fatty acids, leaving remnants called low-density lipoproteins
34
Q

How is LDL absorbed?

A

LDL binds to LDL receptors via the apoplipoprotein B-100 present on the particle

absorbed through endocytosis into the liver and peripheral cells

internalised LDL particles are hydrolysed within lysosome, releasing lipids, chiefly cholesterol

35
Q

What is LDL?

A

One of the five major groups of lipoprotein that transports fat molecules around the body. Delivers fat molecules to cells

36
Q

What are HDLs?

A

High density lipoproteins, which are the densest as the have the highest proportions of proteins to lipids. The smallest

Transport cholesterol mostly to the liver or steroidogenic organs such as adrenals, ovary and testes for the production of steroid hormones

37
Q

HDL production

A
  1. Liver synthesises these lipoproteins as complexes of apolipoproteins and phospholipid
  2. the complexes pick up cholesterol and carry it internally, from cells by interaction with the ATP binding cassette transporter A1
  3. lecithin-cholesterol acyltransferase converts free cholesterol into cholesterol ester which is the sequestered into the lipoprotein core
38
Q

further HDL functions

A

help inhibit oxidation, inflammation, activation of the endothelium, coagulation and platelet aggregation which may help prevent atherosclerosis

39
Q

Function of LDL receptor

A

mediates the endocytosis of cholesterol-rich LDL by recognising the apoprotein B100 that is embedded in the outer phospholipid layer of LDL particles

40
Q

Explain the regulation of LDL receptors

A

number is regulated by the cholesterol content of the hepatocyte

if there is an excess of intracellular cholesterol, then the transcription of the receptor gene will be inhibited, so less LDL receptors will be present

Blood cells- OB/Biochem (8 decks)

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