BIOCHEMISTRY I

A sense of scale

Matter: the physical component that makes up everything Takes up space Has mass Everything excluding empty space and energy.

PARTICLE THEORY OF MATTER All matter is made up of particles All particles in a pure substance are identical (no two different pure substances have the same particles) 3. All particles have space between them All particles are always moving – more energy (heat) produces more movement 5. All particles are attracted to one another If a solid absorbs heat, it may become a liquid. If a liquid absorbs heat, it may become a gas. VIDEO: https://www.youtube.com/watch?v=ndw9XYA4iF0

Atom: most basic unit of matter (the particles)! CHEMISTRY OF LIFE Atom: most basic unit of matter (the particles)! composed of a nucleus (protons & neutrons) and electrons. Particle Charge PROTON + NEUTRON NEUTRAL ELECTRON -

Element: simplest form of a substance CHEMISTRY OF LIFE Element: simplest form of a substance A pure substance consisting of ONE type of atom. Is distinguished by its atomic number. Each element has a specific symbol. Examples: Hydrogen (H), Carbon (C), Oxygen (O), Phosphate (P), Sulphur (S), Neon (Ne), Helium (He), Nitrogen (N), etc. Where can we find information about different elements?...

CHEMISTRY OF LIFE THE PERIODIC TABLE OF ELEMENTS!!!

CHEMISTRY OF LIFE In Biology, we deal mostly with elements within the elements within the first 4 rows (periods) of the Periodic Table. Bulk Elements: C, H, O, N – make up the majority of every living thing. Ex. 96% of human body Minerals: Ma, Mg, P, K, Ca (3.5%) Fe, I (trace elements – tiny amounts)

REPRESENTING AN ATOM A Bohr Diagram Find the element on the periodic table. Determine the number of electrons (same as atomic #) Determine the number of Neutrons (Atomic Mass – Atomic #) Write the number of Protons (P) and Neutrons (N) in the “nucleus.” Draw appropriate number of orbitals around the nucleus (1, 2, or 3) First orbital – 2 electrons max Second orbital – 8 electrons max Third orbital – 18 electrons max

Bohr Diagrams Carbon

Bohr Diagrams Chlorine

Only shows the OUTER electrons of an atom. REPRESENTING AN ATOM A Lewis Dot Diagram Only shows the OUTER electrons of an atom. The shell of the outer electron is called the VALENCE shell, and the electrons are called VALENCE electrons These are the electrons which react with other atoms.

Lewis Dot Diagrams Carbon

Lewis Dot Diagrams Chlorine

ISOTOPES atoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONS Some isotopes are radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time. There are several practical uses for radioactive isotopes: CARBON DATING TRACERS KILL BACTERIA / CANCER CELLS

COMPOUNDS a substance formed by the chemical combination of 2 or more elements in definite proportions Ex: water, salt, glucose, carbon dioxide H20 CO2 NaCl

Inorganic - usually "support" life TWO TYPES OF COMPOUNDS Organic - Contain C, H, and O in some ratio (usually referred to as chemicals of life) Carbohydrates, Proteins, Lipids, Nucleic Acids Inorganic - usually "support" life

Chemical bonds hold the atoms in a molecule together. There are 2 types of chemical bonds IONIC and COVALENT

The Periodic Table Atoms generally want a FULL valence shell! Column 1  1 outer electron, forms a 1+ charge Column 2  2 outer electrons, forms a 2+ charge Column 3  3 outer electron, forms a 3+ charge Column 4  4 outer electrons, no charge, covalent bonding Column 5  5 outer electron, forms a 3- charge Column 6  6 outer electrons, forms a 2- charge Column 7  7 outer electron, forms a 1- charge Column 8  8 outer electrons, neutral, no charge The middle section of transition metals fits here. It is NOT important for our biology lesson.

- one atom donates an electron to another atom There are two types of chemical bonds: 1. Ionic Bonding - one atom donates an electron to another atom positive ion (lost electrons) negative ion (gained electrons)

Covalent Bonding involves sharing electrons between atoms VIDEO: https://www.youtube.com/watch?v=QqjcCvzWwww

Water is essential to living systems Water is made up of polar molecules. -ve “Hydrogen Bonding” +ve

Water Solutions Why is water important?

Water regulates temperature

Water expands as it freezes

Water participates in life’s chemical reactions Cellular respiration Photosynthesis

Water is cohesive

Water dissolves many substances

So stay hydrated!!! Hydrated  Dehydrated 

A universal solvent Water is known as the universal solvent because is dissolves many substances Substances are divided into two categories based on whether or not they dissolve

Hydrophilic Substances Dissolve well in water Ex. Sugar, salt ‘hydrophilic’ means “water-loving” These substances are made of polar molecules or ions Ex. Sugar (sucrose) and table salt

Hydrophobic Substances Do not dissolve well in water Dissolve well in other hydrophobic substances Ex. Vitamins ADEK – fat soluble ‘hydrophobic’ means “water-fearing” Hydrophobic materials often protect against water

MIXTURES Water is not always pure. It is often found as part of a mixture. A mixture is a material composed of TWO OR MORE ELEMENTS OR COMPOUNDS THAT ARE PHYSICALLY MIXED Ex: salt & pepper mixed, sugar and sand – can be easily separated

SOLUTION Two parts: SOLUTE – SUBSTANCE THAT IS BEING DISSOLVED (SUGAR / SALT) SOLVENT - the substance in which the solute dissolves Materials that do not dissolve are known as SUSPENSIONS. Blood is the most common example of a suspension. Cells & other particles remain in suspension.

FORMULA The chemical symbols and numbers that compose a compound ("recipe") Structural Formula – Line drawings of the compound that shows the elements in proportion and how they are bonded Molecular Formula – the ACTUAL formula for a compound C2H6O

ACIDS & BASES Acids: always (almost) begin with "H" because of the excess of H+ ions (hydrogen) Ex: lemon juice (6), stomach acid (1.5), acid rain (4.5), normal rain (6) Facts about Acids Acids usually taste SOUR. You eat acids daily (coffee, vinegar, soda, spicy foods, etc…)

Bases usually feel SLIPPERY to touch and taste BITTER. ACIDS & BASES Bases: always (almost) end with -OH because of the excess of hydroxide ions (Oxygen & Hydrogen) EX: oven cleaner, bleach, ammonia, sea water, blood, pure water Facts about Bases Bases usually feel SLIPPERY to touch and taste BITTER.

Neutralization Reactions When an acid reacts with a base to produce a salt and water.

pH SCALE measures degree of substance alkalinity or acidity Ranges from 0 to 14 0 – 5 strong acid 6-7 neutral 8-14 strong base