The Chemistry of Life Chapter 2

Ch. 2 Outline of topics The atom  composition Types of Atomic interactions pH & buffers  What is pH?  What is a buffer?  Why are they important? Types of organic Molecules

Matter defined as Anything that occupies space or has mass. Matter is composed of atoms. Water balloon balloon Which has a greater mass?

Atoms are composed of: Quarks Superstrings

Subatomic particles affect the element

Elements are composed of identical atoms which are listed as llhttp://news.yahoo.com/s/ap/ /ap_on_sc/sci_new_elements

Atoms interact via their electrons forming compounds

Ionic Interactions Covalent Bonds Hydrogen Interactions Atoms can now form compounds by

Ionic Interactions: based on charge

Examples of Ions CATION ANION

Example of Ionic Compound Salt NaCl Our blood plasma contains Na+Cl-!!!!!

Covalent Bonds A Sharing of Electrons & their influence on hydrogen bonding

Hydrogen Interactions Interaction of hydrogen with oxygen, nitrogen or fluorine Example: H 2 O “polarity”

What does it mean to say: “water is a polar molecule’?  A)The origin of water is the North Pole?  B) electrons are share unequally.  C) electrons are shared equally.

Hydrogen bonding and Lungs Surfactant Decreases hydrogen bonding

Chemical additional concepts important to this course are: pH Buffer 4 Major Organic macromolecules (of the human body)

Blood(7.4) Acidic Alkaline 7.0=Neutral pH is a log scale  pH=log(1/[H+])

What is a buffer? A solution selected or prepared to minimize changes in hydrogen ion concentration which would otherwise tend to occur as a result of a chemical reaction. Chemicals that protect against drastic changes in pH!

Think of a buffer as a chemical “sponge”! “bound H + ” “free H + ”

A common biological buffer H 2 CO 3 H + + HCO 3 - Notice how the hydrogen ion moves from the “bound” state to a “free state” The sponge!

Organic Molecules we will talk about in Human Biology. Proteins Carbohydrates Lipids Nucleic Acids

Proteins: where do we find them? Some Examples:  Heart muscle  Skeletal Muscle  Nervous tissue  Dietary egg, meat, milk Amino Acids: building blocks of proteins

Amino Acids: essential versus non-essential Basic Structure Amino group Acid

An overview of the 20 amino acid building blocks of proteins

(CH0)n: we find them Carbohydrates (CH 2 0)n: we find them Some Examples  Surface of our cells!  Many food sources Building blocks of carbohydrates are simple sugars!

Lipids Examples of where we find them: Examples of where we find them: Are a part of our cell membranes Are a part of our cell membranes Many of our foods Many of our foods

Nucleic Acids Examples of where we find them: Examples of where we find them: In the nucleus and cytoplasm In the nucleus and cytoplasm Building blocks of nucleic acids are “nucleotides”. We will revisit this topic in detail later.

Completes Chapter 2

Be sure and read Chapter 2

5 Kingdom System MoneraProtistaPlantaeAnimaliaFungi Eukaryotes Prokaryotes Kingdom: 12345

Amino Acid Structure

Web links to interactive periodic tables

Proteins: Composed of amino acids There are 20 amino acids

Amino acids are then linked together to form proteins. Proteins are found throughout our bodies.

Bent /Coiled

Three Dimensional

Carbohydrates What are carbohydrates chemically? What are examples of carbohydrates?

The chemical formula for carbohydrates: (CH 2 O)n Note: A carbohydrate will have twice the amount of hydrogens compared to carbon and oxygen.

Carbohydrates are made from Simple sugars: monosaccharides Monosaccharides form polysaccharides

What is an example(s) of a carbohydrate? A) glucose B) starch C) cellulose D) glycogen E) all of the above

Lipids Do not dissolve easily in water Fatty-like material Composed of carbon, hydrogen and oxgen  Does not “fit” formula of carbohydrates

Examples of Lipid-Like Compounds

Nucleic Acids Deoxyribose Nucleic Acid (DNA) Ribose Nucleic Acid (RNA)

DNA: The genetic material of our cell. We will return to this topic in some detail.

Review Question 1: What compounds are most hydrophobic?  Amino acids  Proteins  Lipids  monosaccharide

Review Question 1: What compounds are most hydrophobic?  Amino acids  Proteins  Lipids  monosaccharide

Review Question 2. What type of bond links one amino acid to another amino acid? Ionic bonds Covalent bonds Hydrophobic bonds

Review Question 2. What type of bond links one amino acid to another amino acid? Ionic bonds Covalent bonds Hydrophobic bonds

Review Question 3. An atom that gives up an electron will … Have a negative charge Have a positive charge Be a new element Be an isotope

Review Question 3. An atom that gives up an electron will … Have a negative charge Have a positive charge Be a new element Be an isotope