Carbon Compounds
I. Chemistry of Carbon
A. Organic Chemistry – study of carbon
compounds
1. All organic compounds contain carbon!
2. Examples: carbohydrates, lipids (fats),
proteins, nucleic acids (DNA, RNA)
B. Carbon Structure
1. A C atom has 6 electrons, 2 in the 1st shell, and
four valence/outer electrons
2. Carbon can make four covalent bonds, and
can bond with many types of elements
3. Carbon bonds most often with O, H, and N.
4. Carbon is able to make 4 single, 2 double, and
1 triple covalent bonds with one other atom.
C. Carbon can form millions of different large
and complex structures.
II. Macromolecules
A. Macromolecules are huge, complex
molecules made of similar repeating units.
1. Polymer = macromolecule
2. Monomer = smaller units that fit together to
form polymers (macromolecules)
B. Dehydration Reaction – connects
monomers to from polymers
1. A molecule of water is produced when two
monomers are linked.
C. Hydrolysis – opposite of a dehydration
reaction
1. Polymers are broken down into its monomers
2. A water molecule is consumed.
• Hydro = water
• Lysis = break
III. Types of Macromolecules
A. Carbohydrates
1. Functions:
• main source of energy for living things
(quick energy)
• Plants and Animals also use certain
carbohydrates as structural building
materials
2. Monomer = monosaccharide
•
•
Monosaccharides are single, simple sugars
Glucose (main), fructose, galactose
3. Double sugar = disaccharide
•
•
Two monosaccharides linked together
Sucrose
4. Polymer = polysaccharide (carbohydrate)
•
Hundreds of monosaccharides linked
together
5. Examples of Carbohydrates
• Starch: how plants store glucose
• Cellulose: makes up plant cell walls
• Glycogen: how animals store glucose
• Chitin: makes up exoskeletons of insects
and the cell walls of fungi.
B. Lipids – substances not soluble in water
1. Functions:
• Store energy for long periods of time
• Certain lipids are parts of biological
membranes
• Steroids are lipids that are chemical
messengers
2. Most lipids are formed when a glycerol
molecule combines with fatty acids
3. Fats, oils, waxes, hormones (steroids),
phospholipids
• Saturated Fats – only single bonds are present
between carbon atoms of fatty acids (solid fats)
• Unsaturated Fats – 1 or more double bonds between
carbon atoms of fatty acids (liquid fats – oils)
4. Phospholipids – glycerol with 2 fatty acids
attached a phosphate group
• Make up biological (cell) membranes
C. Nucleic Acids
1. Monomer = Nucleotide; made of 3 parts:
• 5-carbon sugar
• Phosphate group
• Nitrogenous base (N-base)
2. Polymer = Nucleic Acids
• Store and transmit genetic (hereditary)
information about building proteins
• Two types: RNA & DNA
• RNA = Ribonucleic Acid (transmits)
• DNA = Deoxyribonucleic Acid (stores)
D. Proteins
1. Monomer = amino acid
2. Polymer = polypeptide
3. Protein = 1 more polypeptides
4. Amino Acid Structure
- all 20 amino acids have
same basic structure
with one major
difference, the R group
5. The R group determines the function of the
protein.
6. Protein function varies greatly
• Control rate of chemical reactions
• Regulate cell processes
• Structural components (muscle, bone)
• Transport substances
• Fight disease
7. Examples of Proteins
• Muscle proteins
• Pigments
• Hemoglobin (on red blood cells carrying
oxygen)
• Antibodies fighting pathogens
• Enzymes speeding up chemical reactions
8. Four levels of protein organization:
• Primary Structure: order/sequence of
amino acids
• Secondary Structure: how sections of the
amino acid chain can twists and fold
• Tertiary Structure: entire amino acid chain
completely folded
• Quaternary Structure: 2 or more folded
chains come together to form a complex
Metabolism
I. Metabolism is the totality of an organism’s
chemical reactions
A. A metabolic pathway begins with a specific
molecule and ends with a product
B. Each step is catalyzed by a specific enzyme
Enzyme 1
A
Enzyme 2
C
B
Reaction 1
Enzyme 3
Reaction 2
D
Reaction 3 Product
II. Structure of ATP
A. ATP (Adenosine Triphosphate) – shuttles energy
for cells
B. ATP is composed of ribose (a sugar), adenine (a
nitrogenous base), and three phosphate groups
II.
Speeding up Reactions
A. A catalyst is a chemical agent that speeds
up a reaction without being consumed by
the reaction
B. An enzyme is a catalytic protein
C. A ribozyme is catalyst made of RNA
III. Activation Energy
A. Every chemical reaction between molecules
involves the breaking and forming of bonds
1. Reactants absorb energy to break bonds.
2. Products release energy to form bonds.
Sucrase
Sucrose
(C12H22O11)
Glucose
(C6H12O6)
Fructose
(C6H12O6)
B. The initial energy needed to start a chemical
reaction is called the free energy of
activation, or activation energy (EA)
1. Enzymes catalyze reactions by lowering the EA
barrier
IV. Enzymes are Substrate Specific
A. The reactant that an enzyme acts on is the
enzyme’s substrate
B. The active site is the region on the enzyme
where only one type of substrate binds (shape!)
V.
Effecting Enzyme Activity
A. Temperature & pH
1. Each enzyme has an optimal temperature and
pH in which it can function
2. Optimal conditions favor the most active
shape for the enzyme molecule
3. Unfavorable conditions lead to denaturation
(unfolding or changing of enzyme shape)