the chemistry of life cornell notes. the chemistry of life what are things made of?
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The Chemistry of Life
What is ChemistryWhat is Chemistry
Chemistry - is the study of the structure, properties, and composition of substances, and the and the changes that substances undergoes
What Is Matter?• Matter is defined as
anything that occupies space and has mass.
• Matter is actually composed of a lot of tiny little pieces we call atoms that make up Elements.
ElementsThe Chemistry of Life
EVERYTHING is made up of substances called elements
EVERYTHING can be broken down to the simplest parts called elements
Element – substance that cannot be broken down into simpler chemical substances (gold, Silver, Carbon)
Hydrogen
The Chemistry of Life
Element Symbol
Atomic Mass(protons+ electrons+ neutrons)
Atomic Number (# Electrons or Protons)
Trace elementsThe Chemistry of Life
Elements make up all things, Elements make up all things, including living things.including living things.
Some are present in very Some are present in very small amounts in living things. small amounts in living things. These are known as These are known as trace trace elementselements..
AtomsThe Chemistry of Life
Smallest particle of an element
basic building blocks of all elements
structure is crucial to identification
AtomsThe Chemistry of Life
Atoms have a nucleus that contains protons and neutrons
Electrons fly around the nucleus in “shells” (energy levels)
PROTON – Positive Charge
NEUTRON – No Charge
ELECTRON – Negative Charge
Electron Energy Levels
• The 1st shell can hold up to 2 valence e-.
• The 2nd shell can hold up to 8 valence e-.
• The 3rd shell can hold up to 8 valence e-.
The numbers•The large number one in the upper left hand corner is the atomic number. It is the number of protons.
The numbers•The number on the bottom is the atomic mass number. It is also known as the molar mass, or atomic weight. It is the number of protons + the number of neutrons, (when you round it to the nearest whole number).
Isotopes
•Atoms of the same element by definition have the same number of protons.•Atoms of the same element that contain different numbers of neutrons are called isotopes of each other.
Ionic Bonds•Ions are atoms with a charge. They have a charge due to an imbalance in the number of protons and neutron.•The attractive force between two ions of opposite charges is known as an ionic bond.
Quick terms
• metabolism = all of the chemical reactions that take place within an organism
• mixture = a combination of substances in which the individual components retain their properties
• solution = a mixture in which one or more substances (solutes) are distributed evenly in another substance (solvent)
Properties of H2O•it is polar•it can form hydrogen bonds with other molecules•it can experiences capillary action•it resists temperature change•it expands when it freezes
Polar Molecules•Water is polar because the electrons spend more time around the oxygen atom, giving it a partial negative charge and consequently giving the hydrogen atoms partially positive charges.
Hydrogen Bonding•The attraction between opposite charges between hydrogen and oxygen forms a weak bond called a hydrogen bond.
Capillary Action…•is the ability of water to crawl up thin tubes.•This property makes it possible for water to get from roots in the ground to the leaves of the tallest trees.
Diffusion•is the net movement of particles from an area of higher concentration to an area of lower concentration. This occurs due to the random movement of particles known as Brownian motion
Diffusion
• Happens automatically• Particles spread out until
evenly spaced• They move in straight lines
and collide • Motion continues forever
Brownian Movement• atoms do not just stand still in liquids,
solids, and gases• atoms actually move around randomly• atoms can also bump into each other• the random bumping into each other is
called Brownian Movement
Diffusion• the movement of atoms from one area of
high concentration to an area of low concentration
• particles want to even out
Equilibrium
• Even distribution of molecules has been reached
• No “net” change in system, but molecules are still moving
•Imagine the particles are perfume molecules trapped inside a bottle. Remove the lid of the bottle by pressing the button and watch the perfume molecules diffuse throughout the room.
Life Substances•Carbon is the most important molecule to life on Earth.•This is due to the fact that it can form up to four bonds.•Because of this fact carbon can form many different shaped molecules, even using the same atoms.•Glucose and Fructose are isomers of each other.
Variations•Because of this fact carbon can form many different shaped molecules, even using the same atoms.•Glucose and Fructose are isomers of each other.
Polymers•When smaller molecules bond together they form long molecules called polymers.•Glucose and fructose bond together to form sucrose.
Carbohydrates•are composed of carbon, hydrogen and oxygen.•1C: 2H :1O
•CxH2xOx
•These are basically sugars: mono-, di- and poly- saccharides
Lipids•are composed mostly of carbon and hydrogen with a small amount of oxygen•Fats, oils, waxes and steroids are all lipids.•They are non-polar and so don’t mix with water.
•
Proteins•A protein is a large complex polymer composed of carbon, hydrogen, oxygen, nitrogen and sometimes sulfur.•Two or more amino acids held together by a peptide bonds are considered a protein.
Special Proteins•Enzymes are proteins that change the rates of chemical reactions. they are necessary for life as we know it.