BMR of Metabolism

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Metabolism of BMR

• M.Prasad Naidu
• MSc Medical Biochemistry,
• Ph.D.Research Scholar

2

1. Cellular respiration
2. Fermentation
3. Metabolism
4. BMR

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Carbohydrate Metabolism

• The bodys preferred source to produce cellular
  energy (ATP)
• Glucose (blood sugar) is the major digestive
  product and serves as fuel to make ATP

Figure 14.17
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Metabolic Pathways Involved in Cellular
Respiration
Figure 14.18
5
Glycolysis harvests chemical energy by
oxidizing glucose to pyruvic acid
Glucose
Pyruvicacid
Figure 6.9A
Energy yield 2 ATP and 2 NADH
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Pyruvic acid is altered for the citric acid
cycle
Pyruvicacid
Acetyl CoA(acetyl coenzyme A)
CO2
Figure 6.10
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The citric acid cycle completes the oxidation of
organic fuel
Acetyl CoA

• enzymes convert acetyl to CO2 and generate NADH
  and FADH2 molecules

2
CITRIC ACID CYCLE
CO2
Figure 6.11A
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Steps in the Electron Transport System
1. Set up H gradient using energy of e- from
NADH, FADH2 2. Downhill flow of H is used to
make ATP
Figure 3.28
9
cell
outer membrane
inner membrane
mitochondrion
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• An overview of cellular respiration

High-energy electrons carried by NADH
GLYCOLYSIS
ELECTRONTRANSPORT CHAINAND CHEMIOSMOSIS
CITRIC ACIDCYCLE
Glucose
Pyruvicacid
Cytoplasmicfluid
Mitochondrion
Figure 6.8
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Fermentation is an anaerobic alternative to
aerobic respiration

• Without oxygen, cells can use glycolysis alone to
  produce small amounts of ATP
• But a cell must replenish NAD

Glucose
Pyruvicacid
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• In lactic acid fermentation, pyruvic acid is
  converted to lactic acid

• NAD is recycled
• Contributes to muscle soreness

GLYCOLYSIS
2 Pyruvicacid
2 Lactic acid
Glucose
Figure 6.15B
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• Pathways of molecular breakdown

Food, such as peanuts
Polysaccharides
Fats
Proteins
Sugars
Glycerol
Fatty acids
Amino acids
Amino groups
Pyruvicacid
ELECTRONTRANSPORT CHAINAND CHEMIOSMOSIS
Glucose
G3P
AcetylCoA
CITRIC ACIDSCYCLE
GLYCOLYSIS
Figure 6.16
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• Biosynthesis of macromolecules from intermediates
  in cellular respiration

ATP needed todrive biosynthesis
GLUCOSE SYNTHESIS
CITRIC ACIDCYCLE
AcetylCoA
Pyruvicacid
G3P
Glucose
Aminogroups
Amino acids
Fatty acids
Glycerol
Sugars
Polyscaccharides
Fats
Proteins
Cells, tissues, organisms
Figure 6.17
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Body Energy Balance

• Energy intake total energy output (heat work
  energy storage)
• Energy intake from food oxidation
• Proteins, carbs have 4 Cal/gm
• Fats have 9 Cal/gm
• Energy output
• Heat is usually about 60
• Storage energy is in the form of fat or glycogen

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Regulation of Food Intake

• Body weight is usually relatively stable
• Energy intake and output remain about equal
• Mechanisms that may regulate food intake
• Levels of nutrients in the blood
• Hormones leptin, ghrelin
• Body temperature
• Psychological factors

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Metabolic Rate and Body Heat Production

• Basic metabolic rate (BMR) reflects the amount of
  energy spent per unit of time by a body at rest
• Factors that influence BMR
• Body shape (height and weight), gender, body
  composition, age, stress, food intake,
  genetics
• TMR Total Metabolic Rate
• Total energy spent, includes activity above BMR

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Estimation of BMR

• Johnson your weight in kg ( lbs/2.2) x 24 (x
  0.9 if female) Calories per day
• Your weight in kg ( lbs/2.2) x lean
  mass males usually 82-88 females usually
  75-82
• Then check table (next slide)

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ESTIMATION OF RESTING METABOLIC RATE (RMR) BASED
ON FAT-FREE BODY MASS (FFM) FFM RMR FFM RMR FFM R
MR (kg) (kcal) (kg) (kcal) (kg) (kcal) 30 1018 58
1623 86 2228 31 1040 59 1644 87 2249 32 1061 60 1
666 88 2271 33 1083 61 1688 89 2299 34 1104 62 170
9 90 2314 35 1126 63 1731 91 2336 36 1148 64 1752
92 2357 37 1169 65 1774 93 2379 38 1191 66 1796 94
2400 39 1212 67 1817 95 2422 40 1234 68 1839 96 2
444 41 1256 69 1860 97 2465 42 1277 70 1882 98 24
87 43 1299 71 1904 99 2508 44 1320 72 1925 100 253
0 45 1342 73 1947 101 2552 46 1364 74 1968 102 237
3 47 1385 75 1990 103 2595 48 1407 76 2012 104 261
6 49 1428 77 2033 105 2638 50 1450 78 2055 106 266
0 51 1472 79 2076 107 2681 52 1493 80 2098 106 27
03 53 1515 81 2120 109 2724 54 1536 82 2141 110 27
46 55 1558 83 2163 111 2768 56 1580 84 2184 112 27
89 57 1601 85 2206 113 2811