Energy and ATP

• All living organisms require energy to power muscles, pump blood, absorb nutrients, exchange respiratory gases, synthesize new molecules, and establish cellular ion concentrations.
• Glucose is broken down through metabolic pathways, namely cellular respiration.
• The product of breaking down glucose is ATP, which is the currency of cells that gives them energy.

Energy and ATP

• ATP is nucleotide composed of a nitrogenous base adenine, a ribose sugar, and three phosphate groups
• ATP is the central molecule in the transfer of chemical energy within a cell.
• Covalent bonds are the key to ATP's function.

Energy Definition

• Energy is defined as the capacity to do work.
• Types of energy are potential and kinetic.
• Potential energy is the energy of position or stored energy.
• Kinetic energy is energy of motion.
• Potential and kinetic energy can be converted from one class to the other.

Chemical Energy

• Chemical energy is a form of Potential Energy.
• Its energy stored in a molecule’s chemical bonds and is released when bonds are broken.
• It is for movement, molecule synthesis, and establishing concentration gradients.
• Triglycerides are molecules that function in chemical energy storage.

Kinetic Energy Types

• Electrical energy involves the movement of ions across plasma membranes in neurons.
• Mechanical energy involves muscles contracting during walking.
• Sound energy is when sound waves cause vibration of the eardrum.
• Radiant energy is when visible light strikes the retina.
• Radiant energy contains energy of electromagnetic waves.

Laws of Thermodynamics

• Thermodynamics is the study of energy transformations.
• Energy can neither be created nor destroyed; it can only change in form - This is the first law of thermodynamics
• When energy is transformed, some energy is lost to heat - This is the second law of thermodynamics

Chemical Equations

• Chemical Equations are used to express chemical reactions and occur chemical bonds are created.
• Reactants and Products make components of chemical equations

Reactants

• Reactants are substances present prior to the start of a chemical reaction.
• Reactants are written on the left side of the equation.
• An example would be Fe and Cl2

Products

• Products are substances formed by the reaction.
• Products are written on the right side of the equation.

Chemical reaction classification

• The criteria includes looking at the changes in chemical structure
• Chemical Change also criteria.
• Criteria includes reaction being, irreversible, or reversible

Chemical structure changes

• Synthesis reactions: When two or more structures are combined to form a larger structure, like a dehydration synthesis reaction forming a dipeptide.
• Anabolism (AKA anabolic reactions): This is the collective term for all synthesis reactions in the body
• Decomposition reactions: This happens when an Initial large molecule broken down into smaller structures, like a hydrolysis reaction of sucrose into glucose and fructose.
• Catabolism (AKA catabolic reactions): All decomposition reactions in the body are referred as this.
• Exchange reactions: When groups get exchanged between two chemical structures.
• Exchange reactions have both decomposition and synthesis components
• Exchange reactions are most prevalent in human body
• Example of exchange is production of ATP in muscle tissue.
• Oxidation-Reduction (redox) reaction: This happens when reactions get exchanged and electrons where moved from one chemical structure to another.
• Oxidation: Structure that loses an electron.
• Reduction: Structure that gains an electron.
• Reactions (redox) always occur together
• An Example of a redox reaction is Nicotinamide adenine dinucleotide (NAD+)

Chemical Energy Types

• Exergonic reactions: When reactants have more energy within their chemical bonds than the products
• Energy gets released with a net decrease in potential energy in exergonic reactions.
• Decomposition reactions are exergonic.
• Endergonic reactions: Reactants with less energy within their chemical bonds than the products.
• Energy supplied with a net increase in potential energy
• Synthesis reactions are endergonic.

Reaction Types

• Irreversible reaction: a net loss of reactants, and a net gain in products.
• Irreversible Reactions proceeds only to the right.
• Reversible reaction: Does not proceed only to the right
• No net change in concentration of either reactants or products will be considered in equilibrium
• Increase in reactants or decrease in products drives equation to the right
• The Decrease in reactants or drives equation to the right.

Living organisms require energy. Glucose is broken down through cellular respiration, which produces ATP. ATP is the currency of cells that gives them energy. Energy is the capacity to do work.