Biochemistry Blank A little chemistry in Biology

Atoms are the ________________: ______________ are found ______________ ______________ ___________________ in ____________________ Animation from:

Created by G.Baker What are elements?  Each represents a specific type of  Elements to make  While the atoms may have and, they are all built in the same way. Information & picture from Chem4kids at

Created by G.Baker More about Elements..  Elements are the of all matter.  The is a list of all of the that can build matter. It’s a little like the

Atoms differ in __________ of _______, ________,& _______ Image from: Element Song

Atoms that have _________________ have an _____________ and are called __________ They are written with a + or – next to their symbol Na + Cl -

1.____________ 2.____________ 3.____________ 4.____________ 5.____________ 6.____________ Atoms/ions important for living things Used to make bigger molecules Ions = electrically charged atoms 1.____________ 2.____________ 3.____________ 4.____________ 5.____________

ATOMS CAN ______TOGETHER TO _____________________ Ex: Joining 2 HYDROGEN atoms with 1 OXYGEN atom makes one ______ molecule. A _______________ tells _________ of and __________ atoms are in a molecule EX: ________

Chemical Bonds  Compounds such as water, salt, and carbon dioxide are formed  The that holds the substances together is called  Two main types of chemical bonds –  

Properties of Water Water video

Water  A water molecule (H 2 O), is made up of atoms --- one and two. H H O

Oxygen and Hydrogen Atoms oxygenhydrogen  Both oxygen and hydrogen are oxygen  An oxygen atom has protons, __ neutrons, and __ electrons hydrogen  A hydrogen atom has __ proton, __ neutron, and __ electron oxygen  Because oxygen has more protons, it will pull toward itself  This makes a water molecule

Polar/Nonpolar  Polar- a molecule having electrical poles (Positive and negative ends)  Nonpolar- molecule that does not have negative and positive ends

Water is Polar oxygen atom attracts more "fair share" electrons  In each water molecule, the oxygen atom attracts more than its "fair share" of electrons POLAR  The end “acts” The end “acts” Causes the water to be POLAR

Hydrogen Bonds Exist Between Water Molecules  Formed between a highly of a polar molecule and a  One hydrogen bond is, but many hydrogen bonds are

Interaction Between Water Molecules Negative Oxygen end of one water molecule is attracted to the Positive Hydrogen end of another water molecule to form a HYDROGEN BOND

What are the Properties of Water?

Properties of Water  At sea level, pure water and.  At sea level, pure water and.  The boiling temperature of water decreases at higher elevations (lower atmospheric pressure).  For this reason, an egg will take longer to boil at higher altitudes

Properties of Water 1.Cohesion 2.Adhesion 3.High Specific Heat 4.High Heat of Vaporization 5.Less Dense as a Solid

1. Cohesion  Attraction between particles (why water is attracted to itself)  Attraction between particles ( why water is attracted to itself)  Occurs because of water molecules forming hydrogen bonds with nearby water molecules o Results in (a measure of the strength of water’s surface)  Produces a on water that allows insects to walk on the surface of water

Cohesion … Helps insects walk across water

2. Adhesion Attraction between substances. Attraction between substances. Water will make hydrogen bonds with other polar molecules (sugar) as well as with ions (salt) Water will make hydrogen bonds with other polar molecules (sugar) as well as with ions (salt)  -water molecules will “tow” each other along when in a thin glass tube.  Example: process which plants and trees remove water from the soil, and paper towels soak up water.

Adhesion Causes Capillary Action Which gives water the ability to “climb” structures

Adhesion Also Causes Water to … Form spheres & hold onto plant leaves Attach to a silken spider web

3. High Specific Heat - Amount of heat needed to raise or lower of a substance. - Amount of heat needed to raise or lower of a substance.  Water, both for heating and cooling.  Water can absorb or release large amounts of heat energy with little change in actual temperature.

Who Cares about Specific Heat? cooling  It’s the reason water is used in cooling (car radiators, cooling nuclear cores, etc) water temperatures  It’s also the reason why water temperatures don’t fluctuate as much as air temperatures (benefits aquatic life)

4. High Heat of Vaporization  - Amount of energy to convert 1g or a substance from a liquid to a gas  In order for water to evaporate, must be broken (takes a lot of heat to do this)  As water, it removes a lot of heat with it.

Who Cares about Vaporization?  Why do we sweat?

5. Water is Less Dense as a Solid Ice is Ice is as a solid than as a liquid (ice floats) hydrogen bonds constantly being broken and reformed. Liquid water has hydrogen bonds that are constantly being broken and reformed. Frozen water lattice Frozen water forms a lattice whereby molecules are set at fixed distances.

Water is Less Dense as a Solid Which is ice and which is water?Which is ice and which is water?

Water is Less Dense as a Solid WaterIce

Homeostasis  Ability to maintain a despite changing conditions  Water is important to this process because: a. Makes a b. Resists temperature change c. d. Coolant e. Ice protects against temperature extremes (insulates frozen lakes)

WATER is important for all living things Image from: Average person ~~ 60-70% water Babies ~~ 78% Human brain ~~ 90%

WHY Water is important to cells: 1. It’s __________ so it can ____________ lots of different substances. 2. It can _________ lots of ______ _______________________________ very much. (That helps with _________________) 3. ____________________ form between water molecules so they stick together. 4.Water is an important ___________________ in many CHEMICAL REACTIONS.

The pH Scale  Indicates the  Ranges from (equal amounts  pH of (equal amounts H + and OH -) 0 up to 7 is acid  pH 0 up to 7 is acid … H + above 7 – 14 is b  pH above 7 – 14 is basic… OH -  Each pH unit represents a factor of change in concentration  pH 3 is 10 x 10 x 10 (1000) stronger than a pH of 6

Acids  Strong Acids have a pH of  Produce lots of H + ions

Bases  Strong Bases  Strong Bases have a pH of lots of OH - ions  Contain lots of OH - ions and fewer H+ ions

Acids and Bases  The formed in (and the formed by ) can cause certain chemical reactions that may with a cell’s normal functioning (can lead to )

 Our stomachs contain acid (pH of 1-2) that causes chemical reactions with bacteria in food to kill them.  (our stomach is protected by a layer of mucus)

Buffers  or that react with or to prevent sharp, sudden changes in pH  Produced by the body to maintain homeostasis Weak Acid Weak Base