Brainscape's Knowledge GenomeTM

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


See full index

Biochem II Exam II > Lipoproteins > Flashcards

Lipoproteins Flashcards

1
Q

Name the lipoproteins in order of increasing density

A

Chylomicrons, VLDL, IDL, LDL, HDL

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

What determines lipoprotein density?

A

Lipid content

eg Chylomicrons are the least dense because they have the highest lipid content

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

Where is VLDL created?

A

liver

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

Where are chylomicrons synthesized?

A

intestinal epithelium after a meal, they disappear a few hours later

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

What is the first step in digestion of dietary lipids?

A

Emulsification by bile salts. This increases the surface area of the lipid so that it can contact the digestive enzymes.

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

What are the intestinal enzymes thats breakdown dietary triglycerides, cholesterol esters, and phospholipids?

A

pancreatic lipase: cleaves triglyceride ester bonds
colipase: helps attach pancreatic lipase to micelles
cholesterol esterase: hydrolyzes cholesterol esters
phospholipases: break down phospholipids (e.g. A2)

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

Which Apoprotein is responsible for the formation of chylomicrons?

A

B-48

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

How are fatty acids and cholesterol transferred across intestinal mucosa?

A

monoglycerides are absorbed passively

microsomal triglyceride transferase: brings in triglycerides, attach to ApoB-48

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

Once chylomicrons are formed in intestinal epithelium where do they go?

A

lymphatic circulation

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

Where do chylomicrons enter the blood stream?

A

They are transferred from lymphatics to the bloodstream at the left SC vein/thoracic duct

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

What is lipoprotein lipase and where is it located?

A

It is embedded in capillary walls. It delipidates chylomicrons, freeing fatty acids so that they can enter cells.

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

Which Apoprotein activates lipoprotein lipase?

A

C-II

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

Where are chylomicron remnants degraded?

A

THE LIVER!!!!

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

Largest lipoprotein

A

Chylomicron

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

Which apoproteins do chylomicrons contain and what do they do?

A

B-48: form chylomicrons
A-I: activates LCAT(esterifies cholesterol) and binds HDL receptor
C-II: activates lipoprotein lipase
E: recognizes LDL receptor

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

Where is LDL receptor?

A

on target tissues

17
Q

What is the main carrier of endogenously synthesized triglycerides?

A

VLDL

18
Q

Which apoproteins does VLDL contain and what do they do?

A

B-100: binds LDL receptor (docking)
C-II: activates lipoprotein lipase
E: recognizes LDL receptor

19
Q

Where is LDL formed?

A

circulation

20
Q

What does LDL do?

A

transport cholesterol to tissues

21
Q

What apoprotein does LDL contain?

A

B-100:binds LDL receptor

22
Q

What is the smallest lipoprotein?

A

HDL

23
Q

What is the most abundant lipoprotein?

A

HDL

24
Q

Which lipoprotein distributes cholesterol to other lipoproteins?

A

HDL

25
Q

Which lipoprotein takes cholesterol from tissues to the liver for excretion?

A

HDL

26
Q

Which apoproteins does HDL contain and what do they do?

A

A-I: activates LCAT(esterifies cholesterol) and binds HDL receptor
A-II: ?

27
Q

What is CETP (cholesterol ester transfer protein)?

A

involved in reverse cholesterol transport

28
Q

What are exogenous lipids?

A

come from the diet

endogenous=synthesized in the liver

29
Q

What is “good” cholesterol?

A

HDL
it reduces cholesterol in tissues by redistributing it
(LDL delivers cholesterol to tissues)

30
Q

What are the two cycles in lipoprotein metabolism?

A

endogenous and exogenous

31
Q

What is the structure of a lipoprotein?

A

spherical
surface: phospholipids and cholesterol
interior: triglycerides and cholesterol esters
apoproteins thread through the bilayer

32
Q

What is delipidation?

A

The removal of triglycerides from lipoproteins, resulting in a cholesterol rich molecule. Carried out by lipoprotein lipase.

33
Q

Once HDL brings cholesterol to liver, what can the cholesterol then be used for?

A

Cholesterol can be used to form bile salts (entering the exogenous pathway)

34
Q

Which lipoproteins carry fat soluble vitamins?

A

Chylomicrons

35
Q

Which lipoproteins should not be present 3-4hrs after eating?

A

Chylomicrons

Biochem II Exam II (1 decks)

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