energy metabolism · protein synthesis, b. they are with the resulting carbon skeletons being...
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ENERGY METABOLISM KATRIN ROOSITA, MSI.
METABOLISME ENERGI……
Fig 1. METABOLISM
(Courtesy: Rimbawan, 2007)
Organ utama
pengaturan
metabolisme: hati,
jaringan lemak
(adipose), otot , dan
otak.
Peran: penyimpanan,
penggunaan dan
penyediaan sumber
energi (substrat).
SISTEM PENGATURAN
METABOLISME
SISTEM HORMON
SISTEM SARAF
KETER SEDIAAN
SUBSTRAT
Hubungan
substrat – hormon- sistem
saraf
Substrat (glukosa dan protein)
mempengaruhi sekresi hormon
Hormon dan sistem saraf mengatur
metabolisme dan transport substrat.
HORMON UTAMA METABOLISME
http://www.medbio.info/Horn/PDF%20files/
homeostasis_2a.pdf
1 mmol/L = 18 g/dL
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
Penurunan Kadar glukosa darah & sekresi hormon
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
Fungsi insulin di sel target
en.wikipedia.org
Molecular mechanisms of insulin signaling.
Rask-Madsen C , and Kahn C R Arterioscler Thromb Vasc Biol. 2012;32:2052-2059
Copyright © American Heart Association, Inc. All rights reserved.
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
CONTOH:
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
Aktivitas insulin di Sel Target
Ketersediaan Substrat
Berbeda antara kondisi:
- post absorpsi
- puasa/starvation
- olahraga berat
- terjadi gangguan metabolisme dan kondisi
sakit.
POST ABSORPTIVE STATE
2 - 4 HOURS period after
ingestion of a normal meal :
POST ABSORPTIVE STATE
INCREASES in plasma glucose, amino acids, and
triacylglycerols
baby-growths.com
lipogenesis
MECHANISMS OF HEPATIC- AMINO ACID
METABOLISM (in the absorptive period)
The surplus amino acids ARE NOT STORED, but are either:
a. released into the blood for all tissues to use in
protein synthesis,
b. they are with the resulting carbon skeletons being
degraded by the liver pyruvate, acetyl CoA, or TCA
cycle intermediates, these metabolites can be
oxidized for energy or used in fatty acid synthesis.
METABOLISM OF
ADIPOSE TISSUE
in Post Absorptive State
A. Carbohydrate metabolism
1. Increased glucose transport
2. Increased glycolysis:.
3. Increased activity in the hexose monophosphate (HMP) pathway.
B. Fat Metabolism
1. Increased synthesis of fatty
acids.
2. Increased triacylglycerol
synthesis
3. Decreased triacylglycerol
degradation
METABOLISM OF RESTING MUSCLE
in Postabsorptive State
1. Increased glucose transport
2. Increased glycogen synthesis 3. Increased protein synthesis 4. Increased uptake of branched-chain amino acids.
METABOLISM OF BRAIN IN
POSTABSORPTIVE STATE
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
FASTING METABOLISM
Fasting
a. an inability to obtain food,
b. the desire to lose weight rapidly,
c. in clinical situations in which an individual cannot eat because of trauma, surgery, burns, and so forth.
Physiology of Fasting: the absence of food, plasma levels of glucose, amino acids, and triacylglycerols fall, triggering a decline in insulin secretion and an increase in glucagon release.
This sets into motion an exchange of substrates between
liver, adipose tissue, muscle, and brain :
1. the need to maintain adequate plasma levels of glucose
to sustain energy metabolism of the brain and other
glucose-requiring tissues.
2. the need to mobilize fatty acids from adipose tissue, and
the synthesis and release of ketone bodies from the
liver, to supply energy to all other tissues.
INSULIN / GLUCAGON RATIO
availability of circulating substrates
CATABOLIC PERIOD: by degradation of triacylglycerol, glycogen, and protein.
Diseases and Blood Sugar
Regulation
Elevated glucose levels are present in diabetes mellitus, Cushing's syndrome, liver disease, and hyperthyroidism.
Decreased glucose levels are present in Addison's disease, hyperinsulinism, and hypothyroidism.
The most prevalent of these diseases is diabetes mellitus (DM).
Type I DM (insulin-dependent or juvenile-onset) diabetes mellitus, when pancreatic beta cells are destroyed by an erroneous attack by the body's own immune system.
Type II DM, insulin secretion is not reduced; however, there is a reduced sensitivity of target cells to insulin, a phenomenon known as insulin resistance. (Paul I, 2007).
Terima kasih atas
perhatiannya
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REFERENCES
http://www.medbio.info/Horn/PDF%20files/homeostasis
_2a.pdf. Insulin_Glucagon Role in Metabolism.pdf
Tom Brody. Nutritional Biochemistry, 2nd edition,
Academic Press, 1999
Pamela C. Champe & Richard A. Harvey
Biochemistry, 2nd edition, J.B. Lippincott Company,
Philadelphia, 1994.
Illingworth. 2007. Biochemistry for Biologists
Fitness Training.
www.bmb.leeds.ac.uk/.../bioc1110/index.htm .
Rimbawan, 2007. Metabolism Slides