Biochemistry Most of the human body is made up of water, H 2 O, with cells consisting of 65-90% water by weight. Therefore, it isn't surprising that most of a human body's mass is oxygen. Carbon, the basic unit for organic molecules, comes in second. 99% of the mass of the human body is made up of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Oxygen (65%) Carbon (18%) Hydrogen (10%) Nitrogen (3%) Calcium (1.5%) Phosphorus (1.0%)

The Atom The charge of a proton = +1 (positive 1) The charge of an electron = -1 (negative 1) The charge of a neutron = 0 (neutral) The mass of a proton = about 1 amu The mass of a neutron = about 1 amu The mass of an electron is close to zero in comparison to protons and neutrons Protons and neutrons are found in the nucleus Electrons are found in orbitals Atomic Number Mass Number

The Atom atomic number = The number of protons The Atomic Mass = The mass of all protons, neutrons, and electrons. Number of neutrons = The atomic mass rounded – The Atomic number Or since the electrons weigh near zero Number of Neutrons = Number of protons and neutrons – the number of protons The number of neutrons in Helium = = 2

Carbon Draw an atom of Carbon. Identify the parts of the atom Number of Protons 6 Number of Electrons 6 Number of Neutrons = =6 If there is no charge the number of protons = the number of electrons 6P 6N

What is the difference between an atom and an ion? An ion is a atom that has lost or gained an electron.

Ions have a different number of electrons than protons An atom that looses a(n) electron(s) becomes a positively charged ion An atom that gains a(n) electron(s) becomes a negatively charged ion

How are isotopes different?

Isotopes have the same number of protons but different numbers of neutrons

Elements, Molecules & Compounds ELEMENTS: Symbols can be one capital letter or a capital letter with a lower case letter For example: Calcium C = carbon; Ca = Calcium MOLECULES The combination of 2 or more elements  H 2 ; O 2 COMPOUNDS: A substance made of many different elements bonded together Example: H 2 O = ? Made of 2 elements – hydrogen and oxygen NOTE: the subscripts tell # of atoms of each element you have

Example Atoms: H, He, Li, Be, B, C, N, O, F, Ne Example Molecules: O 2, H 2 O, CO 2 NH 3 How is an atom different than a molecule?

Example Atoms: H, He, Li, Be, B, C, N, O, F, Ne Example Molecules: O 2, H 2 O, CO 2 NH 3 How is an atom different than a molecule? Molecules are made up of more than one atom covalently bonded

Example Elements: O 2, H 2, He, N 2 Example Compounds: H 2 O, CO 2 NH 3 How is an element different than a compound?

Example Elements: O 2, H 2, He, N 2 Example Compounds: H 2 O, CO 2 NH 3 How is an element different than a compound? Elements have only one type of atom Compounds have more than one type of atom (IONIC bond)

What atoms are present and how many are in each compound? O 2 = Oxygen H 2 O = Water CO 2 = Carbon dioxide

What atoms are present and how many are in each compound? O 2 is Oxygen 2 Oxygen atoms

What atoms are present and how many are in each compound? H 2 O is Water 2 Hydrogen atoms 1 Oxygen atom

What atoms are present and how many are in each compound? CO 2 = Carbon dioxide 1 Cabon atom 2 Oxygen atoms

Chemical bonds: Forming a compound Bond – to join together atoms using electron energy/force Atoms are most stable when their outer e - cloud is full Elements can share electrons to fill their outer (valence) e - cloud This causes stability

Ionic bonds Forms through the electrical force between oppositely charged ions Opposites attract! ( + wants - ) One loses electron to the other, making one + and one -

Covalent bonds Figure 6.6 Forms when atoms share a pair of electrons Not all atoms easily gain or lose electrons. Some prefer sharing instead These bonds are generally strong Almost all of the substances that make up organisms are molecules held together by covalent bonds

In covalent bonding the electrons are _ shared __ between the atoms. In Ionic bonding atoms are ____ transferred ____ from one atom to another. Covalent bonding forms ____ molecules ______. Ionic bonding forms __ ions ___.

What is polarity in a molecule? Polarity is when there are charged sides in an overall neutral molecule. Larger atoms tend to hog electrons and become slightly negative Oxygen is a neutral molecule but the oxygen side is slightly negative and the hydrogen side is slightly positive.

What is a hydrogen bond? A hydrogen bond is a polar bond where hydrogen is involved. There is an intermolecular attraction between positive and negatively charged sides of different molecules Hydrogen bonds in water

Properties of Water If there are other beings who have seen Earth, he said, they must surely call it “ the blue planet. ” The astronaut was referring to the blue appearance of the water in the oceans, which cover three fourths of Earth ’ s surface. Water is also the single most abundant compound in most living things.

Things to know Hydrogen bond – Because of positive and negative charges of water (polarity). Water attracts other water molecules. Cohesion- attraction between molecules of the same substance. Adhesion- attraction between molecules of different substances Adhesion- Substance to glass (capillary action)

7 properties of water Water: 1. is a powerful solvent – can dissolve things 2. is very cohesive (due to H bonds holding water together) 3. has high surface tension 4. has high specific heat 5. has a high boiling point – a high heat of vaporization 6. is a good evaporative coolant 7. has a high freezing point and lower density as a solid than a liquid (density anomaly)

Water Properties 1. Powerful, versatile solvent – due to polarity

Water Properties 2. Very Cohesive behavior (due to H bonds holding water together)

Water Properties 3. High Surface Tension

Water Properties 4. High Specific Heat

Water Properties 5. High Boiling Point – High Heat of Vaporization

Water Properties 6. Good evaporative coolant

Water Properties 7. High freezing point and lower density as a solid than a liquid (density anomaly) Water is less dense in a frozen state Water Benzene This is unusual for most substances

How is a solution different than a suspension? A solution is homogeneous meaning that the parts dissolve and the mixture looks all the same throughout

Mixtures Solution Solute- NaCl Solvent- water NaCl Dissolving in Water When an ionic compound such as sodium chloride is placed in water, water molecules surround and separate the positive and negative ions.

How is a solution different than a suspension? A suspension is heterogeneous meaning that the parts do not dissolve and you can see different particles in the mixture

What are the parts of a solution What are the parts of a solution: The solvent is the substance doing the dissolving The solute is the substance being dissolved Creamer- solute Coffee- solvent

This is sugar water What is the solvent here? ______ water ____________ What is the solute here? _____ sugar __________________

Macromolecules- giant molecules (make up living cells) Made up of monomers Monomers - smaller single units Polymers – more than two monomers put together 4 macromolecules in living things Carbohydrates Lipids Proteins Nucleic Acids

CompoundMonomer(s) – What single units make them up? Function(s)Examples CarbohydratesMonosaccharide Main source of energy for living things Monosaccharide - glucose Disaccharide- Sucrose (table sugar) Polysaccharide- starch, cellulose, chitin

Carbohydrates

Types of Carbohydrates Sugar is sucrose which is a disaccharide Pasta is a starch which is a polysaccharide When diabetics test their blood they test for glucose which is a monosaccharide

CompoundMonomer(s) – What single units make them up? Function(s)Examples Lipids Lipid molecules are made up of fatty acids and glycerol Used to store energy Saturated Fat- Butter Unsaturated fat- oil Unsaturated fat Saturated fat

CompoundMonomer(s) – What single units make them up? Function(s)Examples ProteinsAmino AcidProteins are used to form bones and muscles Enzymes are proteins that regulate cell processes Meat Enzymes

Proteins

CompoundMonomer(s) – What single units make them up? Function(s)Examples Nucleic AcidsNucleotideStore or transmit genetic information DNA and RNA

Contains C,H,OContains C,H,O Contains C,H,O Contains NContains N,P,SMade of amino acids Made of nucleotidesSubunits are monosaccharides Fats and oilsEnzymesDNA RNA MonosaccharidesDisaccharides Polysaccharides SugarsGlucose Starch Cholesterol KeratinHemoglobinActin Myosin Provides short-term energyProvides long-term energy Holds the genetic codeCatalyzes body reactions Makes up the bodyMakes up cell membranes Body insulationDouble helix Shaped like an E

What determines if a substance is an acid or a base? The concentration of H+ ions (pH) Acids have more H+ ions (protons) Example acids are: Lemon Juice, Hydrochloric acid Bases have more OH- ions (hydroxide) Example bases are: Bleach, Soap 7 is neutral

Acids and Bases &v=RF40cI2O16U

Carbon dioxide + Water  Carbonic Acid What are the reactant(s) in the above reaction? Carbon Dioxide + Water What are the product(s) in the above reaction? Carbonic Acid

What is activation energy? The energy required to start a reaction An exergonic reaction gives off energy An endergonic reaction takes in energy Endergonic ReactionExergonic Reaction

An enzyme is what kind of organic molecule? A protein An enzyme is a catalyst which means it speeds up a reaction An enzyme does this by lowering activation energy (The energy needed to start a reaction.) What are some roles of enzymes in living things? To help with photosynthesis in plants and many body processes