SI Session Metabolism Spring 2010 For Dr. Wright’s Bio 6 Class Designed by Pyeongsug Kim ©2010...

SI SessionSI Session

Metabolism

Spring 2010

For Dr. Wright’s Bio 6 ClassDesigned by Pyeongsug Kim ©2010 [email protected]

mailto:[email protected]

http://sibiology.science-i.com/



Review your understanding of catabolism and anabolism.Be able to discuss a mechanism by which each of the following affects blood glucose levels (i.e., does it increase or decrease blood sugar, and HOW):

InsulinGlucagonsGrowth hormone/insulin-like growth factorsEpinephrineGlucocorticoidsThyroxine

Compare and contrast type I and type II diabetes mellitus with respect to:Age of onsetWhy blood glucose levels are highIs insulin deficient?Recommended treatmentAre beta islet cells damaged?

How does parathyroid hormone and/or vitamin D3 (1, 25-dihydroxyvitamin D3) affect:Reabsorption of calcium from intestineReabsorption of calcium in kidneysResorption of bone

(Think: does it tend to put more calcium in the blood, or less?)What are the consequences of having low blood calcium? (review question!)

Designed by Pyeongsug Kim, ©2010

MetabolismMetabolism: All body’s process that transform energy.

• Catabolism

C A + B + energy Breaking down into smaller molecules

Chemical reactions in Metabolism:Chemical reactions in Metabolism:• Anabolism

A + B + energy C Form larger molecules

Reactants Product

Reactant Products

+ energy

+ energy


*Generally….High levels due to CATABOLISM. Low levels due to ANABOLISM.


Stimulates glycolysis (Catabolism). increase blood glucose.

Stimulate glycogenesis(Anabolism). decrease blood glucose.

The hormones affect Blood glucose levels:

InsulinGlucagonsGrowth hormoneInsulin-like growth factorsEpinephrineGlucocorticoids

Picture from http://www.projectswole.com/diet/how-to-manipulate-insulin-for-fat-loss-and-muscle-gain/


InsulinInsulin↓ Blood glucose by stimulating… -Cellular uptake of glucose -Conversion of glucose to glycogen and fat.

↑Blood glucose

In Beta cell↑insulin secretion

In Alpha cell↓Glucagon secretion

Cells uptake glucose

Liver/muscle: Glucose Glycogen

Adipose tissue: Glucose Triglyceride

↓Blood glucose

_____________: Glucose Glycogen

_____________: Glucose Triglyceride

Glycogenesis

Lipogenesis

Anabolism!!

“-lysis”: Breakdown to smaller molecules“-genesis”: Making to a big molecules


*Insulin is __________ of carbohydrate and lipids.anabolism

(secreted by Pancreas (Beta cells)

GlucaconGlucacon↑ Blood glucose by stimulating… -Making glucose from glycogen and noncarbohydrates (triglyceride and amino acids) -Glycogenolysis(breakdown Glycogen into glucose) in the liver. -Glucogenesis

↑Blood glucose

In Beta cell↓ insulin secretion

In Alpha cell↑ Glucagon secretion

↓ Cells uptake glucose

Liver/muscle: Glucose ← Glycogen

Adipose tissue: Glucose ← Triglyceride

↑ Blood glucose

_____________: Glucose ← Glycogen

_____________: Glucose ← Triglyceride(or noncarbohydrate)

Glycogenolysis

Gluconeogenesis

“-lysis”: Breakdown to smaller molecules“-genesis”: Making to a big molecules

Catabolism!!


(secreted by Pancreas (Alpha cells)


From Dr. Wright’s Bio6 powerpoint

-Both sympathetic and parasympathetic nerves innervate pancreas-Sympathetic, along with epinephrine, stimulates glucagon secretion increase blood glucose-Parasympathetic stimulates insulin secretion ↑ gastrointestinal activity (digestion) decrease blood glucose


ANS system activity in metabolismANS system activity in metabolism


Growth hormone(GH)Growth hormone(GH)-Secreted by A.pituitary glands.-Controlled by GHRH(from hypothalamus)

-stimulates growth in children and adolescents.-More secreted GH during stress and fasting in adults.-increased when fasting, stress, low blood glucose and high amino acid by skeletal muscle.

Picture from http://adolescents.wordpress.com/


Insulin-like Growth factors (IGFs)Insulin-like Growth factors (IGFs)-”Somatomedians” -Polypeptides(protein) produced by liver or many tissues.-mediators of some of GH actions. Cell division Cartilage and bone growth Protein synthesis in muslce & other organs.-Not mediated of GH actions. Lipolysis decreased glucose utilization.


Insulin-like Growth factors (IGFs)(Cont’d)Insulin-like Growth factors (IGFs)(Cont’d)

From Dr. Wright’s Bio6 powerpoint


Growth hormone(GH)Growth hormone(GH)↑ Blood glucose by stimulating… - ↓cellular glucose uptake; Glycogenolysis in the liver

↓ Blood glucosee.g. fasting

In liver ↑Glycogenolysis

↓ Cells uptake glucose

Muscle and other organ: Protein← amino acids

Adipose tissue: fatty acids← Triglyceride

↑ Blood glucose

↑ amino acid in Blood

↓ amino acid in Blood

↑ fatty acids in Blood

↑GH in Anterior pituitary

↑GnRH in Hypothalamus

(secreted by Anterior Pituitary glands)

Hormones for catabolism of carbohydrates and lipids

GlucagonGrowth hormone(GH)EpinephrineGlucocorticoids, Thyroxine


*Insulin is __________ of carbohydrate and lipids.anabolism

*However, GH and Thyroxine promotes protein synthesis anabolism of protein.

EpinephrineEpinephrineIncrease in stress.Produced in adrenal medulla↑ Blood glucose by stimulating… -release glucose from liver (Glycogenesis) -Gluconeogenesis(making glucose from noncarbohydates)

GlucocorticoidsGlucocorticoids-Produced in adrenal cortex-Controlled by ACTH-Increased during prolonged fasting or exercise ↑Blood glucose by stimulating… - ↓cell glucose utilization -Gluconeogenesis(making glucose from noncarbohydates) ↑Lipolysis ↑protein breakdown in muscle.


Thyroxine(T4)Thyroxine(T4)

-Secreted in thyroxine by TSH.-response to low ATP -Increase cell respiration (to make more ATP) ↑ glucose utilization increase metabolic heat as a result of cell respiration. Cold adaptation!!-participate in body growth and CNS in children. ↑ protein synthesis ↑ BMR(Basal metabolic rate)

-Both hypothyroidism and hyperthyroidism Cause muscle wasting(protein breakdown)

-No direct in lipid metaolism.


(secreted by thyroid follicles)

A person with hypothyroidism cannot stand being cold.

Picture from http://abbeygracepink.com/?p=185

Thyroxine(T4) (cont’d)Thyroxine(T4) (cont’d)


-act on nearly every cell in the body. -participate in catabolism of carbohydrates and lipids-Tend to elevate blood glucose.-participate in protein synhesis.

“T4 and T3 tend to ELEVATE PLASMA GLUCE and potentiate the effects of other HYPERGLYCEMIC hormones..ie.. NE, E, cortisol, glucagon, and GH”

Diabetes Type 1 Type 2

onset < 20 years > 40 years

Symptoms Rapid Slow

Proportion 10% 90%

Ketoacidosis? Common Rare

Obesity rare common

Beta cells damaged? Yes No

Insulin secreted? Decreased May be increased

Immunity to islets Yes No

MHC association Yes ?

Treatment? Insulin Diet, exercise, medication

From Dr. Wright’s slide

Vitamin D3 (VD3)Vitamin D3 (VD3)(1, 25-dihydroxyvitamin D3)

-Produce in the skin from sunlight

so, fall VD3 production during winter

-PTH(parathyroid hormone) increase VD3 hormones

-Increase Ca2+ in blood by..... Reabsorption of calcium from intestine

Reabsorption of calcium in kidneysReabsorption CaPO4 crystals of bone

In case of high calcium but normal phosphate VD3 – ↑reabsorption of phosphate and ↑reabsorption of calcium in the kidney.

PTH - ↓↓reabsorption of phosphate and ↑reabsorption of calcium in the kidney.

See table 19.7 Endocrine regulation of Ca and phosphate balance


_____-increase resorption in bone. -increase absorption in small intestine.-increase absorption in kidney. therefore, (lower/rise) Ca2+ level in blood.

________- inhibits dissolution of bone- stimulates excretion of Ca2+ in urine therefore, (lower/rise) Ca2+ level in blood.

Calcitonin

PTH

Calcium levels regulated by hormone- ______________

calcitonin & PTH


When blood Ca2+ level rises…. When blood Ca2+ level rises….

Negative feedback!


When blood Ca2+ level falls…. When blood Ca2+ level falls….

Negative feedback!


Consequences of having low blood calciumConsequences of having low blood calcium-Result from inadequate amount of VD3 or low PTH ↓Reabsorption Ca2+ from bone, kidneys, and intestine ↓ Blood Ca2+

Bone demineralization to increase Blood Ca2+

Osteomalacia, Osteoporosis rickets(in children)

Bone demineralization – loss calcium from the boneBone mineralization – deposit calcium into the bone


SI Session Metabolism Spring 2010 For Dr. Wright’s Bio 6 Class Designed by Pyeongsug Kim ©2010...

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