Transcript Chemistry

The Chemistry of Life
Chapter 2
Ch. 2 Outline of topics

The atom

composition

Types of Atomic interactions

pH & buffers
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

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.
Which has a
greater mass?
balloon
Water balloon
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
Atoms can now form compounds by
• Ionic Interactions
• Covalent Bonds
• Hydrogen Interactions
Ionic Interactions: based on charge
Examples of Ions
CATION
ANION
Example of Ionic Compound

Salt

NaCl
Our blood plasma contains Na+Cl-!!!!!
Covalent Bonds
& their influence on hydrogen bonding
A Sharing of Electrons
Hydrogen Interactions
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Interaction of hydrogen with
oxygen, nitrogen or fluorine
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Example: H2O
“polarity”
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What does it mean to say: “water is a polar
molecule’?

A)The origin of water is the North Pole?
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B) electrons are share unequally.

C) electrons are shared equally.
Hydrogen bonding and Lungs

Surfactant
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Decreases hydrogen bonding
Chemical additional concepts important to
this course are:
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pH

Buffer
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4 Major Organic macromolecules (of the
human body)
pH is a log scale
pH=log(1/[H+])

Alkaline
7.0=Neutral
Blood(7.4)
Acidic
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
The sponge!

H2CO3
H+ + HCO3-
Notice how the hydrogen ion moves from the
“bound” state to a “free state”
Organic Molecules we will talk about in Human Biology.
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Proteins
Carbohydrates
Lipids
Nucleic Acids
Proteins: where do we find them?
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Some Examples:
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Heart muscle
Skeletal Muscle
Nervous tissue
Dietary egg, meat, milk
Amino Acids: building blocks of proteins
Amino Acids:
essential versus non-essential
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Basic Structure
Amino group
Acid
Essential
Nonessential
Isoleucine
Alanine
Leucine
Arginine*
Lysine
Aspartate
Methionine
Cysteine*
Phenylalanine
Glutamate
Threonine
Glutamine*
Tryptophan
Glycine*
Valine
Proline*
Histidine
Serine*
Tyrosine*
Asparagine*
Selenocysteine
**
Pyrrolysine**
An overview of the 20 amino acid
building blocks of proteins
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Carbohydrates (CH20)n: we find them

Some Examples


Surface of our cells!
Many food sources
Building blocks of carbohydrates are simple sugars!
Lipids
Examples
Are
of where we find them:
a part of our cell membranes
Many
of our foods
Nucleic Acids
Examples
In
of where we find them:
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
Kingdom: 1
Monera
2
3
4
Protista
Plantae
Fungi
Prokaryotes
Eukaryotes
5
Animalia
Amino Acid Structure
Web links to interactive periodic tables
http://www.dreamwv.com/primer/page/s_pertab.html
http://www.webelements.com/
Proteins:
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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
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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
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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
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Do not dissolve easily in water
Fatty-like material
Composed of carbon, hydrogen and oxgen
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Does not “fit” formula of carbohydrates
Examples of Lipid-Like Compounds
Nucleic Acids
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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:
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What compounds are most hydrophobic?
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Amino acids
Proteins
Lipids
monosaccharide
Review Question 1:
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What compounds are most hydrophobic?
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Amino acids
Proteins
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Lipids

monosaccharide

Review Question 2.
What type of bond links one amino acid to another
amino acid?
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Ionic bonds
Covalent bonds
Hydrophobic bonds
Review Question 2.
What type of bond links one amino acid to another
amino acid?

Ionic bonds
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Covalent bonds
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Hydrophobic bonds
Review Question 3.
An atom that gives up an electron will…
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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…
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Have a negative charge
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Have a positive charge
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Be a new element
Be an isotope
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