Knpe Lecture 21

Front 1

How does structure dictate function?

Back 1

-the greater the surface area available for diffusion/transport (FLOW) , the greater the conductance

Front 2

What increases surface area?

Back 2

-folds increase surface area and therefore conductance

Front 3

What are the sources of substrate?

Back 3

-Exogenous: Gastrointestinal System

-endogenous: liver and adipose tissue

Front 4

Functions of the Liver

Back 4

1.Filtration and storage of blood

2.Metabolism of CHO, Fat, and Protein 3.Formation of Bile

4.Storage of vitamins and iron

5.Formation of coagulation factors

Front 5

Why Liver Carbohydrate Metabolism ?

Back 5

-are large glycogen stores

important for maintenance of blood glucose

can store and release glucose when needed

- very important during exercise

Front 6

Steps of Glycogenolysis

Back 6

glycogen breakdown

1.Glucose removed by Glycogen Phosphorylase(PHOS)

2.G-6-P converted to Glucose byG-6-phosphatase (removal of Pi)

3.Glucose released into circulation

Front 7

Gluconeogenesis

Back 7

-formation of glucose from protein and glycerol

-importance for maintenance of blood glucose during fasting conditions

Front 8

Steps of Gluconeogenesis

Back 8

sythesis of glucose

1.Amino acids/lactate/pyruvate converted toG-6-P by PEPCKand reverse glycolysis

2.G-6-P converted to Glucose by G-6-phosphatase (removal of Pi )

3.Glucose released into circulation

Front 9

Liver Fatty Acid Metabolism

Back 9

•Synthesisof cholesterol and phospholipids

–Phospholipids contain FFA

•Shippedto other organs and used to synthesize membranes

•FFAalso a source of substrate for energy production

Front 10

Why is liver fatty acid metabolism important ?

Back 10

•Synthesisof fat from protein and carbohydrate –Almost all of the TG synthesis from CHOoccurs in the liver

–Once formed TG are transported to adiposetissue and stored

–Can also be utilized by other tissue formetabolism

Front 11

What are the dangers of fructose ?

Back 11

-small intestine can only absorb a limited amount of glucose per hour

-however, can absorb fructose at the same time

-unlike glucose, fructose is almost exclusively converted to fat in the liver

Front 12

Cirrhosis

Back 12

-replacement of liver tissue with fibrous tissue leading to lose of liver function

-alcoholism, hepatitis , fatty liver disease

Front 13

Where is glucose provided from during exercise ?

Back 13

by the liver via glycogenolysis andgluconeogenesis

Front 14

Sources of Substrate?

Back 14

GI Tract

- digestion and absorption of fat and CHO

Liver

–Triglyceride Storage

–Glycogenolysis

–Gluconeogenesis

–Fatty Acid Synthesis

Front 15

What are adipose tissues?

Back 15

-very simple cells made up of 80-95% triglyerides

-function to store fat and release it when needed

Front 16

Re-esterification

Back 16

occurs when FA-CoA and Glycerol combine to form triglycerides ( mechanism that suggest that blood flow plays a role in regulation of FFA release )

Front 17

What are two insulin- contained receptors ?

Back 17

FAT CD36 and GLUT 4

Front 18

uses of adipose tissue

Back 18

•Adiposetissue stores large amounts of TGs

•TGsare broken down to form FFA by lipases •FFAthen enter the blood and are taken up and metabolized by muscle and otheractive tissue

Front 19

Lipolysis

Back 19

is the breakdown of lipids and involves hydrolysis of triglycerides into glycerol and free fatty acids

Front 20

Adipose Tissue Lipases

Back 20

adipose-enriched protein with triglyceride-specific lipase activity

Front 21

Skeletal Muscle Lipases

Back 21

Front 22

What is an important source of substrate for exercise ?

Back 22

FFA

Front 23

What is the 3 step process in the hydrolysis of TG?

Back 23

•Adipose triacylglyceridelipase (ATGL)

»Cleaves TG

•Hormone sensitive lipase

»Cleaves DG

•Monoacylglyceride lipse

»Cleaves MG