Dr. Jenney -Integration of CHO lipid metabolism

Question 1

What are the key metabolic pathways?

Answer 1

Glycolysis, gluconeogenesis, glycogen metabolism, fatty acid metabolism, amino acid metabolism, citric acid cycle, and oxidative phosphorylation

Question 2

Where is the one place that ALL the metabolic pathways take place?

Answer 2

Liver

Question 3

How are metabolic pathways regulated?

Answer 3

by: 1) compartments within cell
2) organ specialization
3) hormones
4) Enzyme reciprocal regulation= covalent modification (+/- P) OR Allosterically

Question 4

What are the primary and secondary fuels of the brain?

Answer 4

primary= glucose
secondary= ketone bodies (prolonged starvation- b/c fatty acids can cross blood brain barrier)

Question 5

Which glucose transporter works with the brain?

Answer 5

GLUT3

Question 6

At what glucose concentration do coma/death set in?

Answer 6

2.2 mM or less

Question 7

What are the fuels used by muscles? And what is stored by muscles?

Answer 7

used:glucose, fatty acids, and ketone bodies
stored: glycogen
Resting= use Fatty Acids
Starving/workout= use amino acids (increases ammonia)

Question 8

What do muscles do in anaerobic conditions?

Answer 8

convert pyruvate to lactate to regenerate NAD+ to continue glycolysis. lactate then goes into cori cycle (gluconeogenesis)

Question 9

What are the primary, secondary, and tertiary fuels of the heart?

Answer 9

primary= fatty acids
secondary= ketone bodies
tertiary= lactate to pyruvate???-not sure what he was trying to say about the lactate and cardiac muscle in the powerpoint
* heart= ONLY aerobic and no glycogen stores*

Question 10

With prolonged starvation, which organ supplies up to 50% of the blood glucose?

Answer 10

Cortex of the kidney

Question 11

Which type of enzymes converts Triacylglycerols (TAGs) to fatty Acids and glycerol? And where does this take place?

Answer 11

Lipases.

Adipose

Question 12

What are fatty acids bound to in order to be moved to tissues?

Answer 12

Albumin

Question 13

Which are parts of the body have urea cycle enzymes?

Answer 13

Liver and Adipose

Question 14

What form of “fuel” is stored in adipose?

Answer 14

Triacylglycerols (TAGs)

Question 15

What carries TAGs from liver to adipose?

Answer 15

VLDLs

Question 16

What is the liver doing in the FED state?

Answer 16

making and storing fatty acids and glycogen

Question 17

What is the liver doing in the FASTED state?

Answer 17

making ketone bodies

Question 18

Which organ possesses glucokinase? and what pathway is this enzyme involved in?

Answer 18

Liver

Glycolysis

Question 19

Which 2 parts of the body have glucose-6-phosphatase?

Answer 19

adipose and liver

Question 20

Which form of fuel can the liver NOT use as fuel? And why?

Answer 20

Ketone Bodies

b/c the liver has no CoA transferase

Question 21

When is (nor)epinephrine released? And where does it bind?

Answer 21

1. high stress conditions

2. binds to muscle, adipose, and liver receptors

Question 22

What are (nor)epinephrine’s effects in the liver?

Answer 22

1. increases: glycogen phosphorylase and gluconeogenesis (glucose liberation)
2. decreases: glycogen synthase (glucose storage)

Question 23

What are (nor)epinephrine’s effects in the muscles?

Answer 23

increases: glycolysis (by increasing fructose-2,6-BP which increases PFK)

Question 24

What are (nor)epinephrine’s effects in adipose?

Answer 24

Increases: Fatty Acids

Question 25

When is glucagon released? And from where?

Answer 25

1. fasting/low blood glucose | 2. alpha cells of islets of langerhans in Pancreas

Question 26

What are glucagon's effects in the liver?

Answer 26

1. increases: glycogenolysis and gluconeogenesis (glucose liberation) 2. decreases: Glycogen synthesis and Glycolysis

Question 27

What are glucagon's effects in adipose?

Answer 27

increases: lipase (which leads to increased fatty acids and glycerol due to TAG breakdown)

Question 28

When and where is Insulin released?

Answer 28

1. high blood glucose (right after meal) | 2. Beta cells of islets of langerhans in pancreas

Question 29

What are insulin's effects on tissues?

Answer 29

increases: glucose uptake

Question 30

What are insulin's effects on the liver?

Answer 30

1. increases: glycogen synthase and Fatty acid biosynthesis (fuel storage) 2. decreases: glycogen phosphorylase (prevents breaking down of glycogen to release glucose)

Question 31

What are insulin's effects on adipose?

Answer 31

increases: Fatty acid uptake (from VLDLs) and TAG synthesis

Question 32

When is cortisol released? From where? And what does it do?

Answer 32

1. long periods of high stress or low blood glucose 2. from Adrenal cortex 3. changes expression of genes encoding metabolic enzymes by binding nuclear receptors

Question 33

What are cortisol's effects on adipose?

Answer 33

increases: Fatty acid release

Question 34

What are cortisol's effects on muscle?

Answer 34

1. increases: Amino Acid export | 2. decreases: proteins (via breakdown)

Question 35

What are cortisol's effects on the liver?

Answer 35

increases: pyruvate carboxylase and gluconeogenesis