Transcript Chapter 2 Section 3: The Chemistry of Life

Chapter 2
Section 3: The Chemistry of
Life
Atom
Defn: the smallest unit
of _______________
_________________
_________________
and consisting of a
dense, central,
positively charged
nucleus surrounded
by a system of
electrons.
Element
A substance made from _____________________.
Elements _________________________ to simpler
substances by normal chemical means
Molecule
The smallest particle of
a substance _______
_________________
_________________
_________________
_________________
________; a group of
like or different atoms
held together by
chemical forces.
Living things molecules are made up primarily of
different combinations of 6 elements:
______________________________________
______________________________________.
Carbon is the most abundant in life forms.
Generally, all life on Earth is considered to be
Carbon Based
Proteins
Proteins are large molecules that are made
up of subunits called ______________
(2-10,000 proteins linked together)
• http://www.newfitness.com/nutrition/protein.html
• In the 18th century, chemists came across
certain organic substances which were
rather strange. They found that heating
these materials (proteins) changed them
from ______________________ instead
of the other way around.
•One example was the
white of the egg, another
was something they found
in milk (casein). Yet
another was a component
of the blood (globulin).
• In the year 1777, Pierre Joseph Macquer, a
French chemist, decided to give all these
strange substances, which coagulated upon
being heated, a common name: albuminous
(after the word, albumen, the name that Pliny
had given to egg white.)
• In 1839, the Dutch chemist Gerardus Johannes
Mulder found that they all contained carbon,
hydrogen, oxygen, and nitrogen. Proud of the
discovery, he named his four-element formula,
protein, from a Greek word meaning "of first
importance." That is how much he thought of his
formula! But it stuck as the name for the strange
substances.
What are proteins? Proteins consist of many
smaller units, called ___________, linked
together in __________. Amino acids are
organic acids which contain nitrogen.
Amino Acids are ____________________
____________________________. They
also contain carbon, hydrogen, and
oxygen. Some also have sulfur or
phosphorus.
• Each completed chain of amino acids is
called a peptide. This is actually a
synonym for a complete protein. The
amino acids are linked together, to form a
complete peptide chain, which is a protein.
• Each protein is carefully assembled by
_________________ from materials lying
around. And it never makes a mistake.
• That tiny thing, a single protein, moves around,
picking up amino acids here and there and
sticking them together. Higher and higher goes
the assembly, until that little protein has made
another complete protein with specific ________
_________ in a specific _____ with specific
________________! (scavenger hunt)
Nearly all types of proteins bend or fold
and curve back and forth over, under,
and around themselves;—and each
protein has a certain pattern it follows.
Scientists call these the "fold patterns."
If the folds do not occur in the proper
way, the protein cannot perform its
functions properly.
Some Protein Functions
•
•
•
•
Hemoglobin– a protein in the body that
attaches to ___________ for delivery
throughout the body. ( 4 O2 per
hemoglobin molecule)
Enzymes-assist chemical reactions
Muscle fibers
Hormones
•
Proteins are broken down into amino
acids and then relinked to form new
proteins
Feathers, spider webs, and hair
___________________________________
Food Sources of Proteins
Meat
Beans
Dairy Products
Nuts
What’s a Vegetarian??
Carbohydrates
Carbohydrates are a
group of compounds
_________________
Cells use
carbohydrates
for _________
______________
When energy is
needed – cells
break down
carbohydrates
to release
stored energy
Two Types of Carbohydrate
Simple – ____________ sugars linked together
Complex – ___________ sugar molecules linked
together
»
»
»
Excess sugar is stored as _____________
___________________Some is made by your
body and stored in the liver
Plants make a complex carbohydrate called
starch
(potatoes, carrot)
Glycogen
• The form of carbohydrate storage in
animals
Starch
• The form of carbohydrate storage in plants
Food Sources of Carbohydrates
•
•
•
•
____________
____________
____________
____________
Lipids
AKA:
FAT
&
OIL
Lipids ______________________________
___________________________________
Lipids do not mix with water (oil and water)
Two types of Lipids
1.fats – at room temp (72 deg.) -______________
2.oils – at room temp - ______________________
Human Fat Cells
Human Cross section – Mid Abdominal
FATS
• Source of ___________ energy
• _________________
• _________________
Survival of the Fittest???
Phospholipids
Phospholipids are ____________________
__________________________________.
• The phospholipid molecules form 2 layers in
water which together form the cell membrane.
(note: living things are 70% water)
• A phospholipid molecule has two distinct ends:
The __________________________________
______________________________________
The hydrophilic head is __________ water.
Water soluble things can dissolve through it
The hydrophobic tail is ___________ water.
It allows fats to dissolve through it.
The membranes of cells are a fluid, they are
__________________, which means some things can
pass through the membrane and other things cannot.
Food Sources of Fats
• _____________
• _____________
• _____________
Nucleic Acids
• Nucleic acids are ______________________
_____________________________________.
• The nucleic acids are the building blocks of
living organisms. Often termed the
blueprints for life.
• __ __ __ is a nucleic acid
What’s a Nucleic Acid?
• DNA, RNA, mRNA, tRNA are examples of
nucleic acids
All nucleic acids are made up of the same building
blocks (MONOMERS). Chemists call the
monomers NUCLEOTIDES. The five nucleotides
are called... URACIL, CYTOSINE, THYMINE,
ADENINE and GUANINE. In the same way that
there are twenty (22) essential amino acids, there
are five (5) essential nucleotides.
ATP
• Adenosine triphosphate
ATP energizes
Me
• The major fuel for all cell
activities that require energy
• The energy released when
molecules of carbohydrates,
lipids and sometimes proteins
are broken down is
transferred to ATP