our second lesson gives us an overview of chemistry what is matter is the first question matter is everything that occupies space and has weight it comes in three different states it comes in solids liquids and a gas State we can easily see that in water solid is ice liquid is water and a gas state is vapor or steam what is energy then energy has no Mass nor does it have weight energy is measured by its effects on matter it has the ability to do work and put matter into motion it comes in a kinetic form which is when we actually perform work like a muscle contract or it comes in potential or in inactive form and that's a way to store it like a battery in a car or fat in our body or simply energy molecules that we can store in muscle tissue and release when we need it that would be the form glycogen we have different types of energy in our body we have chemical energy that is energy that is stored in substances in molecules in bonds that need to be broken to set that energy free we have one specific energy molecule in our system and that's called ATP will be very important coming up soon we also have electrical energy in that form movement of charged particles are the energy so these are ions these are electrolytes that have a little bit of a charge with them and can Flo from one space to the next and create uh an energetic current and then we have mechanical energy and that's an actual muscle contraction for example radiant energy is light energy such as visible light or also x-ray energy conversion is easy the only problem is we will lose heat in the process let's Dive Right into atoms which means incapable of dividing so for us that's the smallest stuff we're going to look at all matter is made up of a limited number of substances called elements and one particle of an element is called an atom looking at their structure they all have more or less the same makeup they all have a nucleus which houses proton and protons are positively charged um um particles and then it also has neutrons and neutrons do not have a charge in them and then around that nucleus we have orbits or shells we can call them and in those we have electrons floating around electrons have a negative charge so now we have an in the nucleus we have a proton which a positive charge and in the shell on the outside we have a negative charge when we combine atoms chemically we make molecules and chemical reactions occur when atoms combine or dissociate from one another they form chemical bonds with another atom bonds are the interaction between electrons of reacting atoms that means the electron in the outer shell furthest apart from the center to nucleus will react with another electron of another atom's outer shell that kind of makes sense doesn't it the veilance is the outermost shell or Orbit One atoms veence electron is the one that will interact with another atom's veence electrons and then they will form a chemical bond so therefore it is the veence that determines the chemical behavior of an atom that brings us to the octet rule and the octet rule also means the rule of eight and that means that an atom's veence carries a maximum of eight electrons and is reactive if it carries less than eight and this is true for most atoms not the very early numbers but this octet rule is quite helpful to understand the reactivity of an atom an inert element is one that has a full veence so that one is not going to be reactive only the atoms that don't have a full outer shell the veilance will be reactive holy moly well let's talk about chemical bonds we have a few types two main ones the ionic bond and the calent bond those are the main ones in an ionic bond electrons are transferred from one atom to another this will create charged atoms and in our body those are salts or electrolytes so they will be helpful when we have to have electrical energy generated in our body we'll use that for that this is like an atom here with with with transferring an electron is like when one atom steals the electron from another atom the the other one just gives it up that's why those elements at the end will be charged molecules in a calent bonds electrons are shared between atoms this makes them more stable depending on how many electrons are shared we're going to call those different bonds we call it a single bomb for one electron a double bomb for two and a triple bond if there's three electrons that are going to be shared calent bonds bonds also come in polar and in non-polar flavors a nonpolar coent molecule shares the electrons equally and a good example of that is carbon dioxide on the other hand a polar coent bond shares the electrons unequally and water is such an example H2O that's not unequal sharing and then that unequal sharing creates creat creates a little bit more positivity and a little bit more negativity on different poles and that will create its own type of bond and that's known as a hydrogen bond so positive and negative poles of a polar coent molecule are attracted to each other forming weak connections these are bonds that often form inside larger molecules they're called intr molecular bonds so they're in such as in protein we have such bonds that help form the shape of a protein when we're looking at chemical reactions there are some general types we have a decomposition reaction then we have a synthesis reaction and lastly there we have an exchange reaction a decomposition reaction is also called a catabolic uh reaction or we have a catabolic process that takes place and that's a process of breaking something down destruction is that when we do that we release energy an example of that is digestion when we have larger food molecules go into smaller particles a synthesis reaction is known as also known as an anabolic or a constructive reaction or process this uses energy because in this one we're making stuff so we're building houses well as well we're building protein uh and that takes energy so that examples of that is is is growth or repair of worn out tissues Etc and then the exchange reaction uh is a molecular switch and then here we have uh lastly factors that influence chemical reactions such as temperature the higher the temperature the faster the atoms move the higher the rate of reaction because we Buon into each other faster concentration the higher the concentration of an atom the higher the chance that we have an interaction particle size the smaller the particles the faster they move the more possibility they have to interact and then lastly here we have the biological catalyst and that is an enzyme so if you see the word enzyme you're always thinking of a catalyst and what is a catalyst it is a molecule that helps drive a chemical reaction forward all right let's right into biochemistry