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.new-fitness.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

SimpleSimple – ____________ sugars linked together

ComplexComplex – ___________ 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 are ______________________

_____________________________________.

• The nucleic acids are the building blocks of living organisms. Often termed the blueprints for life.

• __ __ __ is a nucleic acid

Nucleic Acids

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

• 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

ATP energizes Me