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.

Matter is composed of atoms.

Water balloon

balloonWhich 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

http://www.dreamwv.com/primer/page/s_pertab.htm

lhttp://news.yahoo.com/s/ap/20110608/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

CATIONANION

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: H2O

“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

H2CO3 H+ + HCO3-

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 Essential Nonessential

Isoleucine Alanine

Leucine Arginine*

Lysine Aspartate

Methionine Cysteine*

Phenylalanine Glutamate

Threonine Glutamine*

Tryptophan Glycine*

Valine Proline*

Histidine Serine*

Tyrosine* Asparagine*

Selenocysteine

** Pyrrolysine**

Amino groupAcid

An overview of the 20 amino acid building blocks of

proteins

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Carbohydrates (CH(CH20)n: we 0)n: we find themfind 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 Are a part of our cell membranesmembranes

Many of our foodsMany of our foods

Nucleic Acids

Examples of where we find them:Examples of where we find them:

In the nucleus and cytoplasmIn 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

Monera Protista Plantae AnimaliaFungi

EukaryotesProkaryotes

Kingdom: 1 2 3 4 5

Amino Acid Structure

http://www.dreamwv.com/primer/page/s_pertab.html

http://www.webelements.com/

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: (CH2O)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) glucoseB) starchC) celluloseD) glycogenE) 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