Potential energy-stored energy, not yet in a usable form (potential energy can be viewed as motion waiting to happen). Ex: A car on top of a hill, water at the top of a waterfall or stored behind a dam.
Kinetic energy-The energy of motion [energy in a usable form (ex:ATP)]. Kinetic energy is energy at work, whenever we use energy to do work, it is in the kinetic state. Ex: A car racing down a hill, even electrical energy (light coming from a lamp) is kinetic energy.
Thermal energy-energy in the form of heat.
Chemical energy-energy from molecules in the biological sense.
Types of Work
Chemical work-chemical energy from molecules is used to break down products.
Mechanical work-mechanical work is shown by organisms that move and is always involved with movement.
Laws of Thermodynamics
The formal study of heat and other forms of energy is called thermodynamics. The total amount of energy always remains constant and energy cannot be created or destroyed, this is the first law of thermodynamics. The second law of thermodynamics is that energy tends to disperse spontaneously.
-Energy flows from organized (carbs) to disorganized (heat). The reason we say this is because heat is dissipated everywhere and it can’t be used because it’s highly disorganized. Entropy is a measurement of a systems disorder. Ex: The only thing that can happen to a clean room, which is highly organized, is it can get messy, so it's highly unstable. A very dirty room is highly disorganized and all that can happen is it can get cleaner, so it's highly highly stable.
-Energy is the capacity to do work. Cellular energy is a molecule ATP and in respiration cellular energy is produced.
One-way flow of energy-Energy flows through the world of life in one direction: from the environment, through organisms, and back to the environment. The flow of energy is one way because with each transfer of energy, some energy escapes as heat. Cells do not use heat to do work. Thus, all of the energy that enters the world of life eventually leaves it, permanently.
Photosynthesis (Note:the ultimate source of energy is sunlight and photosynthesis takes place in chloroplast. Chemical Equation: energy+CO2+H2O-->C6H12O6+CO2) gets us to the production of carbs and CO2, then respiration (which occurs in mitochondria) uses the carbs and CO2 (C6H12O6+CO2-->ATP+CO2+H2O) to get us the rest of the way through the flow of energy, ATP+CO2+H2O is produced at the end.
-Enzymes enhance the rate of reactions without being changed by them, a process called catalysis. Most enzymes require cofactors (metal ions) or coenzymes (organic cofactors) and can move backwards and forwards and are reusable. Because enzymes are reusable, they are more efficient and this helps save cell energy/maintain homeostasis. Enzymes lower activation energy by boosting local concentrations of substrates (a molecule that is specifically acted upon by an enzyme) and orienting them in positions that favor reaction, causing the fit between a substrate and the enzymes active site (pocket in an enzyme where substrates bind and a reaction occurs). An enzyme is very specific to it's particular substrate, the 3-dimensional shape of the molecule determines its function (their recognition is "lock and key" and is passed on the tertiary structure).
-In case of enzyme deficiency/absence, the entire chain of the chemical reaction gets disrupted. There is an abnormal increase in the level of substrates, which can be toxic for the human body. Also, there is a decline in product formation, leading to deficiency for the nutrient, wherein the enzyme deficiency/absence occurs.
Metabolism refers to activities by which cells acquire and use energy as they make and break apart organic compounds. Metabolism requires enzymes and runs on ATP.
Why are reactions in the body organized into metabolic pathways?