The Chemistry Of life

Which elements make up 96% of body mass by weight

Oxygen (O) 65%, Carbon (C) 18-18.5%, Hydrogen (H) 9.5-10%, Nitrogen (N) 3%

What are the most common elements of the human body

Major: Oxygen (O) 65%, Carbon (C) 18.5%, Hydrogen (H) 9.5%, Nitrogen (N) 3%, Calcium (Ca) 1.5%, Phosphorus (P) 1%

Minor Sulfur (S) 0.25%, Potassium (K) 0.20%, Sodium (Na) 0.15%, Chlorine (Cl) 0.15%, Magnesium (Mg) 0.05, Iron (Fe) 0.006%

What does a Shell Model Look like

What does a Cloud Model look like

What is the octet Rule

When elements lose, pair , or share electrons to make complete outer shells with 8 electrons

How many electrons are in the first shell to be considered full

2 electrons

Ionic Bond

The giving or taking of electrons between two elements/atoms to make a full shell

Covalent Bond

The sharing of electrons between two elements to make a full shell

Molecule

Two or more atoms bonded togther

Ex. H₂ , C₆H₁₂O₆

Compound

Two or more different kinds of atoms bonded together

Ex. C₆H₁₂O₆

What makes up 60-80% of the volume of living cells

Water

What is what kind of compound

The most important inorganic compound

Functions of Water: Transportation

Substances dissolved in water move easily throughout the body

Major [blank] in body

Functions of Water: Lubrication

Decreases friction between body structures

Ex. Joints

Functions of Water: Cushions

Absorbs sudden force of body movements

Functions of Water: Excretion of waste

Unwanted substances dissolve in water are easily eliminated

Cohesion

Attraction between water molecules due to hydrogen bonding

Adhesion

Attraction between water molecules and a substance other than water

Surface Tension

Inward pulling of cohesive forces at surface of water

What does surface tension cause in the lungs

Moist sacs of air in lungs to collapse

Surfactant, a lipoprotein, prevents collapse

Temperature

Measure of kinetic energy of atoms or molecules within a substance

Specific Heat

Amount of energy required to increase temperature of 1 gram of a substance by 1 degree Celsius

Does water have a high specific heat

Yes, water’s value is extremely high due to the energy needed to break hydrogen bonds

This contributes to keeping the bodies temperature constant

What are Salts

Ionic compounds that dissociate into ions in water.

Ions/Electrolytes conduct electrical currents in solution

Why are ions/electrolytes important

Ionic balance is vital for homeostasis

Ions play specialized roles in body functions

Ex. sodium, potassium, calcium, iron

What are salts made of

Salts contain cations more than H⁺ and anions more than OH^-

Solutions

Homogeneous mixture of material smaller than 1 nanometer

Colloids

A gel like substance

Smaller particles than a suspension but larger than in a solution

Suspension

Material larger in size than 1mm mixed with water

Materials do not remain mixed unless in motion

Emulsion

A mixture of two or more substances/liquids that do not mix

Solvent

Present in greatest amount usually a liquid

Solute

Present in smaller amounts

Acids

Proton donors that release (hydrogen ion H⁺) in solutions

HCl —> H⁺ + Cl^-

What are some important acids

HCl, HC₂H₃O₂ (HAc) and H₂CO₃

Bases

Proton acceptors (Take up H⁺ form a solution)

NaOH——> Na⁺ + OH-

What accepts an available proton

OH- accepts an available proton (H⁺)

OH- + H⁺ ———→ H₂O

What are some important bases

Bicarbonate ion (HCO₃ --) and ammonia (NH₃) are important bases

What do acid solutions contain

They contain [ H⁺ ]

As [ H⁺ ] increases pH decreases

Acid pH

0-6.99

pH scale logarithmic

a pH 5 solution has 10 times more H⁺ than a pH 6 solution

What do alkaline solutions contain

They contain bases

As [ H⁺ ] decreases/ as [OH^-] increases alkalinity increases

As [ H⁺ ] decrease pH increases

Alkaline pH

7.01-14

What pH is water

7 it is neutral

Chemical energy

Stored in bonds of chemical substances

Electrical Energy

Results from movement of charged particles

Mechanical Energy

Directly involved in moving matter

Radiant or Electromagnetic energy

exhibits wavelike properties

Ex. visible light, ultraviolet light, and x-rays

Chemical reactions

Occur when chemical bonds are formed, rearranged or broken

Represented as chemical equations

What are in chemical equations

Molecular formula for each reactant and product

Relative amounts of reactants and products, which should balance

Reactant

The kind and number of reacting substances

Product

The substance that is formed

Synthesis reactions

Combination to form a larger more complex molecule

Always involve bond formation

Anabolic, constructive

A+B——> AB

Decomposition Reactions

Molecules are broken down into smaller molecules

Reverse synthesis reactions

Involve breaking of bonds

Catabolic, degradative

AB ——→ A + B

Exchange Reactions

Bonds are made an broken, the reactants change partners

Reverse synthesis reactions

Involve breaking of bonds

Catabolic, degradative

AB + C ——→ AC + B

What are rate of reactions influenced by

Increase in temperature = Increase in reaction rate

Decrease/smaller particle size = Increase in reaction rate

Increase of a concentration reactant = Increase in reaction rate

Catalysts

Increase rate of reaction without being chem8cally changed, lower activation energy

Factors influencing collisions

Increase temperature = increased energetic collisions (normal body temp is optimal)

Lower activation energy = Faster reaction rate

Increased reactants = increased frequency of collisions

Molecules must collide with proper orientation = successful collision (determined by shape of molecules)

Metabolism

All chemical reactions of the body

Catabolism (Catabolic)

Energy releasing (Exergonic) decomposition reactions

Break covalent bonds

Produces smaller molecules

Anabolism (Anabolic)

Energy-storing (Endergonic) synthesis reactions

Require energy input

Ex. Production of protein or fat

How are catabolism and anabolism linked

Anabolism is driven by the energy released by catabolism

Oxidation reaction

A chemical reaction in which a molecule gives up electrons and releases energy

A molecule is [blank] when it loses electrons

The [blank] agent is the electron acceptor

What is usually the oxidizing agent

Oxygen

Reduction Reaction

Any chemical reaction in which a molecule gains electrons and energy

Molecule is [blank] when it accepts electrons

The [blank] agent is the molecule that donates electrons

Oxidation reduction reactions

Chemical reactions where electrons are being lost and gained