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1

Integration level- flow of key metabolites between different pathways

Cellular level

2

Integration level- interdependence of different organs and tissues

Tissue and organ level

3

Major metabolic fuel

Glucose

4

What is the storage form of glucose?

Glycogen

5

Cells that contain _________ can generate glucose and send to the blood stream.

Name some examples

Glucose 6-phosphate.

Liver, kidney, and small intestine

6

Other sources of glucose

TAGs and glucogenic amino acids- used for gluconeogenesis

7

What carries nutrients to the liver?

Portal vein

8

______ turn nutrients into fuel

Hepatocytes

9

What causes enzymes to increase or decrease?

Changes in diet

Needs of other tissues

10

What allows for passive diffusion of glucose in and of the blood? Found in hepatocytes

GLUT2

11

What is the glucose phosphorylating enzyme?

Glucokinase (Hexokinase IV)

12

What makes glucokinase soo special?

It has a higher Km (10mM) than other kinases (4mM)

13

When is glucose-6-phosphate not made? Why?

When glucose is low
other tissues need the glucose?

14

Where is GLUT2 found?

In the liver and pancreas

15

What are the monosaccarides in the liver that can convert into glucose-6-phosphate?

Fructose, galactose, and mannose

16

What are the potential fates of glucose-6-phosphate in the liver?

1- It is dephosphorylated by glycogen phosphorylase (yields free glucose to send to other tissues)

2- Makes glycogen with phosphoglucomutase

3- Enter glycolysis to make Acetyl-CoA for FA biosynthesis

4- Enter glycolysis pathway to make acetyl-CoA for ATP generation

5- Enter Pentose phosphate pathway to yield NADPH

17

Glucose-6-phosphate metabolism generates nucleotides and reductive biosynthesis power in the form of ______ via what pathway?

NADPH

Pentose phosphate pathway

18

Potential fates of amino acids in the liver:

1- Biosynthesis of proteins for the liver and other tissues

2- Biosynthesis of hormones and nucleotides

3- Biosynthesis of CAC intermediates or pyruvate for gluconeogenesis

19

What is pyruvate converted to acetyl CoA?

For liver cell energy and conversion to lipids

20

Potential fates of fatty acids in the liver:

1- Synthesize liver lipids

2- Oxidize to acetyl-CoA and NADH

3- Convert to phospholipids

4- Convert to TAGs for storage

5- Carried to heart and muscle for oxidation

21

Fate of Acetyl-CoA in the liver:

1-Sent thorugh CAC and oxidative phosphorylation to make ATP

2- Some is converted into cholesterol, which in turn becomes either bile salts or steroid hormones in the blood

3- Excess Acetyl-CoA is converted to ketone bodies for the brain and heart in carbohydrate restriction and fasting

22

Free fatty acids in the blood bind to what?

Albumin

23

Ketone bodies include: (3)

Beta-hydroxybuterate

Acetoacetate

Acetone

24

When are ketone bodies made?

when oxaloacetate pools are insufficient to condense with acetyl-CoA

25

Why are ketone bodies able to enter the brain?

they do not bind to albumin

26

Ketone bodies are _____ for energy in place of, or to supplement ____.

oxidized

glucose

27

% of ketone bodies that supply energy for the brain:

For the heart:

70

30

28

Liver functions: (4)

Provide glucose and ketones for other organs

Process amino acids into urea, etc

Store nutrients (iron, fat soluble vitamins)

Detoxify and solubilize organic compounds via cytochrome P45 system

29

Adipocyte function: (4)

Carry out glycolysis though oxidative phosphorylation

Convert acetyl-coa into fatty acids

Use FA to make TAGS

Release FA when other tissues need them

30

FA make TAGS from ______ found in intestinal lipids

and ____ found in the liver

chylomicrons

VLDL