lipotoxicity/ ketogenesis

Question 1

when adipose tissue cannot keep up with TAG storage needs and a spill over of FFA into the blood occurs what happens?

Answer 1

lipotoxicity

Question 2

macrophages cause what type of response?

Answer 2

inflammatory response

Question 3

FFA entering non-adipose cells and stored as TAG is called?

Answer 3

ectopic fat

Question 4

when we have increased FFA in the blood what happens?

Answer 4

the liver takes them to get them out of the blood

Question 5

with prolonged TAG storage and Lipid droplet size increasing what happens to hepatocytes?

Answer 5

they start looking like adipocytes

Question 6

what are the toxic lipids to the liver?

Answer 6

FFA
TAG, DAG
Lysophosphatidyl choline LPC 
Ceramides
Free Cholesterol

Question 7

what are some examples of causes of lipotoxicity in the liver?

Answer 7

Non-alcoholic fatty liver disease
Non-alcoholic steatohepatitis
inhibition of insulin receptors leading to insulin resistance

Question 8

low/no carb stimulates what?

Answer 8

ketogenesis

Question 9

low/no carb stimulates B-oxidation which produces what?

Answer 9

acetyl CoA

Question 10

once acetyl CoA is increased where does it go?

Answer 10

some goes to krebs cycle

excess goes to ketogenesis

Question 11

where does ketogenesis occur?

Answer 11

mitochondrial matrix

Question 12

what are the 3 ketone bodies we learned about?

Answer 12

acetone- exhaled by product
acetoacetate- functional
B-hydroxybutyrate- functional

Question 13

functional ketones are transported from where to where?

Answer 13

liver in the blood to target tissues where it is converted back into acetyl CoA

Question 14

what are the 2 ketogenic amino acids?

Answer 14

Leucine
Lysine

Lindsay Lohan

Question 15

how does fat turn into acetyl CoA?

Answer 15

OHOT

Question 16

can acetyl CoA be turned into glucose?

Answer 16

no- pyruvate dehydrogenase is irreversible

Question 17

the liver can _____ ketone bodies but it cannot _____ the ketone bodies

Answer 17

make; oxidize/consume

Question 18

how do we make HMG CoA in ketogenesis?

Answer 18

acetoacetyl CoA + H2O + acetyl CoA -> HMG CoA

HMG CoA synthase is the enzyme needed

Question 19

what enzyme is needed to make HMG CoA in ketogenesis?

Answer 19

HMG CoA synthase

Question 20

what is the rate limiting step in the synthesis of ketone bodies?

Answer 20

HMG CoA synthase

Question 21

the cytosolic version of HMG CoA synthase is a part of what pathway?

Answer 21

cholesterol synthesis pathway

Question 22

cholesterol and ketones are made from the same materials BUT they are made under different conditions, what are the differences?

Answer 22

excessive fat burning in liver creates ketones

excessive sugar and insulin results in cholesterol

Question 23

what are the materials cholesterol and ketones have in common?

Answer 23

both start from acetyl CoA

both have HMG CoA as a precursor

Question 24

where does cholesterol synthesis happen?

Answer 24

cytosol

Question 25

what are the causes of high concentration of ketone bodies?

Answer 25

accelerated B-oxidation low carb starvation uncontrolled diabetes mellitus

Question 26

what stimulates fat burning and inhibits liver glycolysis?

Answer 26

glucagon

Question 27

glucagon also stimulates?

Answer 27

gluconeogenesis

Question 28

what inhibits pyruvate dehydrogenase complex (prep step)?

Answer 28

acetyl CoA

Question 29

during gluconeogenesis, oxaloacetate is stolen from where?

Answer 29

krebs cycle to make glucose

Question 30

what does ketogenesis do to gluconeogenesis?

Answer 30

it stimulates it because gluconeogenesis makes glucose from pyruvate which is necessary when glucose levels in the body are low

Question 31

in order to convert pyruvate into oxaloacetate, what enzyme do we need?

Answer 31

pyruvate carboxylase

Question 32

what is the coenzyme needed to use pyruvate carboxylase?

Answer 32

biotin

Question 33

in the mitochondria when we have increased FA oxidation and reduced OAA oxaloacetate what is the result?

Answer 33

an oversupply of acetyl CoA

Question 34

when we have too much acetyl CoA what do we make?

Answer 34

ketone bodies

Question 35

as our body produces ketone bodies, there is a shift in metabolism called?

Answer 35

ketosis

Question 36

during ketosis what do we use for energy?

Answer 36

ketone bodies

Question 37

as ketone bodies rise in the blood, what happens to gluconeogenesis?

Answer 37

it slows down resulting in less protein being consumed

Question 38

what is it called when gluconeogenesis consumes less protein due to elevated ketone bodies?

Answer 38

protein sparing- ketogenesis is also protein sparing

Question 39

during oxidation of ketones, acetoacetate and B-hydroxybutarate are transported in the blood to?

Answer 39

extrahepatic tissues

Question 40

increased B-hydroxybutarate and acetoacetate in the blood lowers pH and leads to?

Answer 40

ketoacidosis | coma, death

Question 41

increased ketones in blood and urine =

Answer 41

ketonemia | ketonuria

Question 42

when can ketogenesis be dangerous?

Answer 42

starvation uncontrolled type 1 diabetes too extreme low carb diet/ prolonged

Question 43

what are some conditions the ketogenic diet would be good for?

Answer 43

``` type 2 diabetes epilepsy cancer alzheimers parkinson's disease ```

Question 44

what are the stimulators of ketogenesis?

Answer 44

glucagon decreased glucose increased AMP, ADP (decrease ATP) increased B-oxidation (increased acetyl CoA)

Question 45

what are the inhibitors of ketogenesis?

Answer 45

increased ATP insulin increased glucose decreased acetyl CoA