بخشی از پاورپوینت
اسلاید 1 :
بيو انرژتيک در تغذيه- جلسه هفتم
Bioenergetics in nutrition
اسلاید 2 :
متابوليتها (واسطههاي متابوليک) موادي هستند که در طول کاتابوليسم و آنابوليسم مواد مغذي تشکيل ميشوند. معمولاً آنها مولکولهاييکوچک هستند. اسيد پيروويک متابوليت گلوکز است. اسيد پيروييک يک ترکيب حدواسط است که در يک مسير متابوليک، در حين کاتابوليسم گلوکز تشکيل ميشود. يک مسير متابوليک، يک سري از واکنشهاي بيوشيميايي است که توسط آنزيمها کاتاليز ميشود، و معمولاً از سطح انرژي بالاتر به سطح انرژي پايينتر در جريان است.
با استفاده از ايزوتوپهاي راديواکتيو کشف شد که بسياري از بافتها در حالت ثابت کاتابوليسم-آنابوليسم هستند و يا در تحرک و جايگزيني با بافتهاي جديد تشکيل شده ميباشند (ترن اور):
براي مثال، بافت چربي ذخيرهي ساکن از ليپيدها نميباشد و دائماً با ليپيدهاي جديد در حال جايگزيني است.
بافت ماهيچه اي دستخوش تخريب و تشکيل مجدد ميشوند.
در انسانها، در طول روز 1 تا 2 درصد از کل پروتئين بدن دچار تغيير ميشود. پروتئينهاي کبدي نيمه عمري از 30 دقيقه تا چند ساعت دارند.
استخوان ساختار پويايي است با حرکت مواد معدني استخوان به دنبال رسوب بافت استخواني جديد، به طور پيوستهاي در حال بازسازي است.
متابوليسم و متابولوميکها
اسلاید 3 :
طبقهبندي مسيرهاي متابوليسمي
مسيرهاي كاتابوليسمي
مسيرهاي آنابوليسمي
مسيرهاي آمفيپاتيك
ارتباط بين مسيرهاي كاتابوليسمي و آنابوليسمي
بيوانرژتيك:
مطالعه تغييرات انرژي در واكنشهاي بيوشيميايي است:
در بيوانرژتيك تنها به انرژي حالت ابتدايي و انتهايي اجزاي واكنش توجه مي شود
بيوانرژتيك به چگونگي انجام واكنش (مكانيسم واكنش) و زمان لازم براي انجام واكنش اشاره نمي كند
اسلاید 4 :
Bioenergetics:
is the subject of a field of biochemistry that concerns energy flow through living systems. This is an active area of biological research that includes the study of thousands of different cellular processes such as cellular respiration and the many other metabolic processes that can lead to production and utilization of energy in forms such as ATP molecules.
the energy involved in making and breaking of chemical bonds in the molecules found in biological organisms.
Growth, development and metabolism are some of the central phenomena in the study of biological organisms.
The role of energy is fundamental to such biological processes.
The ability to harness energy from a variety of metabolic pathways is a property of all living organisms.
Life is dependent on energy transformations; living organisms survive because of exchange of energy within and without.
Bioenergetics is the part of biochemistry concerned with
اسلاید 5 :
Energetics is the study of energy requirements and the flow of energy within systems
bioenergetics is the study of the balance between energy intake in the form of food and energy utilization by animals for life-sustaining processes
processes?: tissue synthesis, osmoregulation, digestion, respiration, reproduction, locomotion, etc.
the original energy source for food energy is the sun.energy from the sun is converted by photosynthesis into the production of glucose glucose is the hydrocarbon source from which plants synthesize other organic compounds such as COH, protein, lipids as previously mentioned, one must consider the quality of these sources
اسلاید 6 :
Biochemistry. The study of the flow and transformation of energy in and between living organisms and between living organisms and their environment.
Psychology. A therapeutic approach that incorporates breathing, movement, body exercises, psychotherapy, and free expression of feelings to enhance self-awareness and well-being and relieve physical and emotional tension.
Read more: http://www.answers.com/topic/bioenergetics#ixzz2Gei6KV4M
bioenergetics is such an umbrella term
نگاه چتري
بيوانرژتيک گستره زيادي را در همه علوم به ويژه تغذيه در بر مي گيرد.
اسلاید 7 :
Metabolism
The sum of all the chemical processes occurring in an organism at one time
Concerned with the management of material and energy resources within the cell
Catabolic pathways
Anabolic pathways
Catabolic Pathways
Pathways that release energy by breaking down complex molecules into simpler compounds
Cellular respiration
C6H1206 + 6O26CO2 +6H20 + ENERGY
Anabolic Pathways
Pathways that consume energy to build larger, complicated molecules from simpler ones
Polymerization
Photosynthesis6CO2 +6H20 + light C6H1206 + 6O2
اسلاید 8 :
Bioenergetics
Study of how organisms manage their energy resources
Energy is the capacity to do work, to move matter
Kinetic energy: energy that is in motion
Potential energy: stored energy based on location or structure, ability to do work even if it is not doing work at the time.
The rearrangement of atoms in molecules may result in the potential energy of the molecule being converted into kinetic energy
Kinetic energy: energy of motion; all atoms exhibit kinetic energy as all molecules are in motion
Potential energy: amount of energy stored as a result of position or location (gravitational)
Mechanical potential energy (elastic deformation)
Bound energy within internal structure
Releasing potential energy transforms
اسلاید 9 :
Forms of energy:Energy can exist in various forms. Examples are:
- Radiation energy: the radiation from the sun contains energy, and also the radiation from a light or a fire. More solar energy is available when the radiation is more intense and when it is collected over a larger area. Light is the visible part of radiation;
- Chemical energy: wood and oil contain energy in a chemical form. The same is true for all other material that can burn. The content of chemical energy is larger the larger the heating value (calorific value) of the material is and, of course, the more material we have. Also animate energy (delivered by bodies of human beings and animals) is, in essence, chemical energy. Furthermore, batteries contain chemical energy;
- Potential energy: this is, for example, the energy of a water reservoir at a certain height. The water has the potential to fall, and therefore contains a certain amount of energy. More potential energy is available when there is more water and when it is at a higher height;
- Kinetic energy: this is energy of movement, as in wind or in a water stream. The faster the stream flows and the more water it has, the more energy it can deliver. Similarly, more wind energy is available at higher windspeeds, and more of it can be tapped by bigger windmill rotors;
- Thermal energy or heat: this is indicated by temperature. The higher the temperature, the more energy is present in the form of heat. Also, a larger body contains more heat;
- Mechanical energy, or rotational energy, also called shaft power: this is the energy of a rotating shaft. The amount of energy available depends on the flywheel of the shaft, i.e.:. on the power which makes the shaft rotate;
- Electrical energy: a dynamo or generator and a battery can deliver electrical energy. The higher the voltage and the current, the more electrical energy is made available.
اسلاید 10 :
Energy-Releasing and Energy-Conserving Processes
Exergonic reactions
Chemical processes that release energy to its surroundings
Downhill processes
Endergonic reactions
Chemical processes that store or absorb energy
Uphill processes
مكانيسم جفت شدن فرايندهاي انرژي زا و انرژي گير در سلول
با استفاده از نوعي واسطه اجباري مشترك مانند واكنشهاي دهيدروژناسيون
تهيه يك تركيب حامل پرانرژي در واكنشهاي انرژي زا و مصرف آن در واكنشهاي انرژي خواه
اسلاید 11 :
Coupled Reactionsواکنش هاي جفت شده يا مزدوج
اسلاید 12 :
Anabolism and Catabolism
Coupled Reactions
واکنش هاي جفت شده يا مزدوج
اسلاید 13 :
Linear and Circular Pathways
Coupled Reactions
واکنش هاي جفت شده يا مزدوج
اسلاید 14 :
Biologic Work in Humans and animal
Performance of mechanical work
Chemical work in biosynthesis of macromolecules
Active transport of molecules and ions concentrating various substances in & out of cells.
اسلاید 15 :
ترموديناميك
ترموديناميك در ارتباط با انتقال حرارت و انجام كار صحبت مي كند. ترموديناميک قوانيني دارد که كاربردشان عبارتند از:
بررسي تغييرات انرژي در واكنش ها
پيشگويي جهت انجام واكنش ها
مفاهيم ترموديناميك
سيستم: مجموعه اي از موادي كه متحمل يك فرايند فيزيكي , شيميايي يا بيوشيميايي خاص ميگردد.
محيط: احاطه كننده سيستم
جهان واكنش = محيط + سيستم
اسلاید 16 :
قانون اول ترموديناميك (قانون بقاي انرژي)
كل انرژي جهان ثابت است و فقط انرژي از شكلي به شكل ديگر تبديل مي شود.
قانون دوم ترموديناميك:
فرايندهايي خودبه خودي انجام مي شوند كه در آن ها بي نظمي (آنتروپي) جهان واكنش افزايش يابد.
These two seemingly abstract statements are the foundation of the net energy systems we use to formulate diets and evaluate energy status of animals. There are six forms of interchangeable energy states: Chemical, Light, Electric, Mechanical, Heat , Nuclear
The terms open or closed systems refer to whether or not energy can be transferred between the system and its surroundings (can energy be imported or exported)
Laws of Thermodynamics &Einstein’s theory of relativity
In addition to those laws, bioenergetics is also based on Einstein’s theory of relativity, i.e., the equivalence between mass and energy.
In other words we can convert measures of mass (pounds) to measures of energy (calories).
اسلاید 17 :
In terms relevant to animal nutrition, Energy input must equal energy output plus or minus any change in body energy.
Although energy can enter an animal’s body via:
radiation (e.g., direct exposure to the sun’s rays),
convection (flow of heat from the air to the body) and
conductance (flow of heat from a warm surface that is in contact with the animal) these inputs are usually quite minor (for example convection can only occur when environmental temperature exceeds body temperature which is not very common).
مصداق قانون اول ترموديناميک در تغذيه دام
اسلاید 18 :
Therefore this discussion will assume the only energy input into the body is via diet.
The main ways energy can leave an animal is via feces, urine, gas (predominantly methane), milk, and heat.
A small loss of mass (i.e., energy) occurs via the body surface (hair, skin cells, body secretions containing carbon, etc) but these losses are usually quite small (<0.5% of energy consumed) and will be ignored in this discussion.
In most situations the first law of thermodynamics in animal nutrition terms can be written as:
Body Energy Change = IE - FE - UE - GE - MiE - Heat
where: IE = intake energy (E), FE = fecal E, UE = urineE,
GE = gas E, MiE = milk E
مصداق قانون اول ترموديناميک در تغذيه دام
بر اساس قانون اول ترموديناميک مبناي محاسبات در همه سيستم هاي تغذيه اي در تغذيه دام روش فاکتوريل است.
اسلاید 19 :
The second law can be paraphrased as:
no transformation of energy is 100% efficient and the inefficiencies are lost as heat. Examples of energy transformations performed by an animal are:
1) chemical energy of food converted into muscle,
2) chemical energy of a food converted into physical activity (e.g., breathing or walking),
3) chemical energy of body fat converted into milk. When each of these transformations are done part of the energy input is converted to the energy output and part of is converted to heat.
مصداق قانون دوم ترموديناميک در تغذيه دام
The synthesis of lactose from propionic acid by a dairy cow illustrates this principle.
If the cow makes lactose only from propionic acid it takes 4.7 molecules of propionic acid to make 1 molecule of lactose.
If 4.7 moles of propionic acid are burned completely it releases 1725 kcal of heat and 1 mole of lactose, if completely combusted releases 1350 kcal of heat.
The cow took 1725 kcal of chemical energy (propionic acid) and converted it into 1350 kcal of chemical energy (lactose) which means that 375 kcal (1725 - 1350) were lost and that loss was heat.
The efficiency of that reaction was 1350/1725 = 0.78.
The conversion of chemical energy into mechanical energy in an animal results in essentially all the chemical energy being converted into heat even though a mechanical process has occurred.
اسلاید 20 :
ساير اشکال انرژي به جز انرژي شيميايي ذخيره شده از نوع حرارتي هستند
The reason for this is when a muscle fiber contracts to do mechanical work it returns to it original place (i.e., no net change in distance has occurred) and therefore no ‘true work’ has been conducted (even though the animal may have walked a mile, the part of the muscle fiber that moves during contraction has not moved relative to the other part of the muscle fiber.
Therefore if an animal expends 1 Mcal of chemical energy from the diet to walk, breath, pump blood, etc. that 1 Mcal of chemical energy is lost from the body as heat.
The massive amount of heat lost (~10,000 Mcal or more than 26 million BTU’s) as the cow grew from birth to maturity is a result of the inefficiencies of converting one form of chemical energy into another form and from the physical activity associated with life.
