23 Ketone Bodies, Complex Lipids, Adipose tissue Hormones

Question 1

In what tissue and organelle are ketone bodies made?

Answer 1

ketone bodies are made in the mitochondrial matrix of cells in the liver

Question 2

What kind of conditions favor ketogenesis in liver cells?

Answer 2

ketone body synthesis is stimulated under these conditions: fasting, starving, high fat/low carb diet, heavy alcohol consumption, and diabetes

Question 3

Which tissues use ketone bodies as fuel?

Answer 3

all tissues use it, except for 2

Question 4

Which tissues do not use ketone bodies as fuel and why not?

Answer 4

Liver, it lacks enzyme, succinyl CoA: acetate transferase and Red blood cells, which do not have mitochondria, the site of ketone body synthesis

Question 5

ketone body synthesis regulation

Answer 5

TBC

Question 6

What are examples of the physiological functions of glycerophospholipids?

Answer 6

1. main components of cellular membranes along with sphingomyelin 2. make up lipoproteins, bile, lung surfactant 3. sources of polyunsaturated fatty acids, like Arachidonic Acid, leads to eicosanoid production

Question 7

Phosphatidic acid is necessary for glycerophospholipid synthesis, so how is it produced?

Answer 7

it is made from glycerol-3-phosphate and 2 fatty acyl CoAs.

Question 8

glycerophospholipids made from diacylglycerol

Answer 8

phosphatidylethanolamine,
phosphatidylcholine,
phosphatidylserine

Question 9

glycerophospholipids made from CDP-diacylglycerol intermediate

Answer 9

phosphatidylinositol
phosphatidylglycerol
cardiolipin

Question 10

How is diacylglycerol formed from phosphatidic acid?

Answer 10

Phosphatidic acid loses a phosphate, by the enzyme phosphatase, to form diacylglycerol

Question 11

examples of activated head groups

(glycerophospholipid synthesis)

Answer 11

CDP-ethanolamine and CDP-choline

Question 12

example of activated backbone (glycerophospholipid synthesis)

Answer 12

CDP-diacylglycerol

Question 13

role of phosphatidylglycerol

Answer 13

it makes cardiolipin, which is found in the inner mitochondrial membrane, and makes the membrane impermeable to small molecules

Question 14

what is phosphatidic acid?

Answer 14

a key intermediate and precursor of glycerophospholipids

Question 15

purpose of ketone bodies

Answer 15

ketone bodies serve as a source of fuel during fasting, starvation or a high fat diet. they are synthesized mainly in the liver mitochondria whenever fatty acids are high in the blood.

Question 16

physiological functions of sphingolipids

Answer 16

are involved in intercellular communication, are antigenic determinants of ABO blood groupd, used as virus receptors, and component of myelin sheaths

Question 17

the three classes of glycolipids, and are all made by reacting with

Answer 17

cerebrosides, globosides and gangliosides are all made by reacting with ceramides

Question 18

forming cerebosides

Answer 18

ceramide reacts with a UDP sugar, have only one sugar attached

Question 19

forming globosides and gangliosides

Answer 19

ceramide reacts with additional sugars to form globosides, and ceramide reacts with additional sugars and a sialic acid (NANA) to form a ganglioside

Question 20

the enzyme and the substrates of glycosphingolipids

Answer 20

use of glycosyltransferases to add activated sugars, UDP sugars

Question 21

how are glycosphingolipids degraded?

Answer 21

sphingolipids are degraded by lysosomal enzymes, they are known as acid hydrolyses, until all that is left is the ceramide

Question 22

causes of sphingolipidoses

Answer 22

these are lysosomal storage diseases caused by decreased activity of lysosomal enzymes, due to the mutational defects of enzymes specifically involved in the breakdown of sphingolipids

Question 23

defective enzyme of Tay Sachs disease, what would it normally cleave

Answer 23

defective enzyme is called Hexosaminidase A, it normally cleaves ganglioside GM2, but causes buildup of vacuoles in cells since they’re not cleaved, leading to a disruption of normal cell function

Question 24

adipose tissue as an endocrine gland and what hormones does it release

Answer 24

adipose tissue not only stores TAGs, but also secretes the hormones leptin and adiponectin to regulate fat and glucose metabolism

Question 25

what causes leptin release

Answer 25

an increase in TRIGYCERIDE levels, stimulates leptin release, it signals us to stop eating by binding to leptin receptors in the brain

Question 26

what causes adiponectin release

Answer 26

its secretion is reduced as adipoctyes get larger

Question 27

Adiponectin affect on muscle metabolism

Answer 27

adiponectin causes a signal cascade, by binding to receptors, it activates AMPK, and a nuclear transcription factor, PPAR.
Leads to enhanced fatty acid oxidation and enhanced glucose uptake by the muscle

Question 28

conditions present for the diagnosis metabolic syndrome, and are at increased risk for

Answer 28

increased waist circumference, elevated triglycerides, reduced HDL, elevated blood pressure and elevated fasting glucose, are at increased risk for Type 2 Diabetes and cardiovascular disease