ENERGY METABOLISM

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
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KETER SEDIAAN
SUBSTRAT
SISTEM HORMON
SISTEM SARAF
Hubungan
substrat – hormon- sistem
saraf
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Substrat (glukosa dan protein)
mempengaruhi sekresi hormon
Hormon dan sistem saraf mengatur
metabolisme dan transport substrat.
Kadar glukosa plasma vs sekresi hormon
HORMON UTAMA METABOLISME
EFEK BIOLOGIS GLUKAGON
http://www.medbio.info/Horn/PDF%20files/homeostasis_2a.pdf
Fungsi insulin
en.wikipedia.org
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
baby-growths.com
INCREASES in plasma
glucose, amino acids, and
triacylglycerols
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.
2.
3.
Increased synthesis of fatty
acids.
Increased triacylglycerol
synthesis
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 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.
INSULIN / GLUCAGON RATIO
availability of circulating substrates
CATABOLIC PERIOD: by degradation of triacylglycerol,
glycogen, and protein.
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.
Diseases and Blood Sugar
Regulation
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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).
OVERVIEW OF METABOLIC PATHWAYS
AND SYSTEMS OF ENERGY METABOLISM
Nucleic
Acids
GLYCOGEN
PROTEIN
TRIACYLGLYCEROLS
Ribose-5-P
Glucose
Lactate
Glucose-6-P
Amino
Acids
Pyruvate
Urea/NH3
Free Fatty Acids
Acetyl-CoA
Ketone
Bodies
Figure 2. Energy systems (DR. RImbawan, 2007)
H2 O
CO2
ATP
METABOLISME ENERGI SAAT
AKTIVITAS FISIK (OLAH RAGA)
METABOLISME GLIKOGEN
Liver glycogen stores increase during
the well-fed state .
Muscle glycogen is not affected by
short periods of fasting (a few days)
and is only moderately decreased in
prolonged fasting (weeks).
Muscle glycogen is synthesized to
replenish muscle stores after they
have been depleted, for example,
following strenuous exercise.
Terima kasih atas
perhatiannya
alternativemagazineonline.co.uk
REFERENCES
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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
Review Article

a.
b.
c.
d.
e.
Teori Dasar Biokimia ttg:
Regulasi : hormonal dan saraf
Ketersediaan Substrat
Parameter /biomarker
Metode
Hasil