Ketones

Question 1

Ketones

Answer 1

water soluble molecule derived from lipids

can be used in place of glucose to provide acetyl-CoA for krebs cycel

Question 2

Does acetone ionize appreciably?

Answer 2

no

but acetoacetic acid does

Question 3

ketosis

Answer 3

elevated ketones concentration in tissues (usually measured in blood)

Question 4

Ketonemia

Answer 4

elevated levels of ketones in the blood

Question 5

ketonuria

Answer 5

presence of ketones in the urine

Question 6

Ketoacidosis

Answer 6

metabolic acidosis resulting from excessive production of ketones

Question 7

Predominant source of ketones in healthy animals

Answer 7

long chain fatty acids

Question 8

In hepatocytes LCFAs can be used to:

Answer 8

synthesize TGs for export in VLDLs (mainly)

produce acetly-CoA for the krebs cycle by undergoing beta-oxidation in mitochondria

Question 9

LCFA must be bound to _____ in order to enter mitochondrion

Answer 9

carnitine

Question 10

___ acetyl-CoA units are condensed to form acetoacetate, which can be further metabolized into beta hydroxybutyrate and acetone

Answer 10

2

Question 11

Ketones are particularly taken up by?

Answer 11

cardiac and skeletal muscle

Question 12

Most ketones are used to fee?

Answer 12

the krebs cycle in peripheral tissues to generate ATP

Question 13

Can the brains of many veterinary species utilize ketone? Can humans?

Answer 13

No- require glucose

yes

Question 14

The most abundant rumen VFA is?

Answer 14

acetate

Question 15

The next most abundant VFA in the rumen is?

Answer 15

propionate

-almost all of it enters the liver and enters gluconeogenesis pathway

Question 16

The least abundant rumen VFA is?

Answer 16

butyrate

Question 17

Ruminants are at greatests risk of ketoacidosis because they have

Answer 17

two sources of ketones

• LCFAs mobilized from adipose for energy
• VFAs from fermentation

Question 18

Ketosis triggers

Answer 18

starvation or anorexia
lactation or late pregnancy
insulin deficiency

Question 19

What causes excessive ketone production

Answer 19

• lipolysis during states of negative energy balance
• increased acetyl-CoA production from LCFA in liver
• negative energy balance also diverts oxaloacetate into the gluconeogenesis pathway

Question 20

Negative energy balance states include?

Answer 20

fasting or starvation
type I diabetes
late pregnancy or lactation

Question 21

Why do ruminants have a greater risk of fatty liver?

Answer 21

because they are less efficient than other species at exporting VLDLs from hepatocytes

Question 22

Fatty liver is common in dogs and cats because?

Answer 22

with diabetes mellitus fat is mobilized for energy as cells fail to take up glucose and VLDL synthesis in the liver cannot keep up with TG synthesis

Question 23

pregnancy toxemia

Answer 23

ketoacidosis during late pregnancy when when cows/ewes cannot take in as much feed as usual

Question 24

Clincial signs of ketosis

Answer 24

Appetite suppression/anorexia
Weight loss
Weakness
Decreased milk production
fat accumulation in liver and liver damage