Biochemistry
Notes
Biochemistry
• Definition– the scientific study of the chemical composition of
living matter
– AND of the chemical processes that go on in living
organisms.
Biochemistry Facts
1.
2.
3.
4.
The human body is composed of about 70% water.
The remaining 30 % is made up of a group of compounds
known as ORGANIC COMPOUNDS.
Organic means that it contains the elements carbon and
hydrogen.
Examples of organic compounds include
1.
2.
3.
4.
Carbohydrates
Lipids
Proteins
Nucleic acids – Part of DNA
Carbohydrates (sugars)
• Facts
1. All carbohydrates (carbs) contain the elements C,
H, and O.
1. C- Carbon
2. H – Hydrogen
3. O - Oxygen
2. The atoms of H and O are in a 2:1 ratio. (two
hydrogen atoms to every one oxygen atom).
Carbohydrates Continued
1. The names of most end in the suffix “ose”.
1. Ex. Sucrose, Fructose, Maltose, Glucose
2. Are the main energy source for the body.
Types of Carbohydrates
1. They are classified into one of three groups
based on their size.
– Monosaccharide
– Disaccharides
– Polysaccharide
Monosaccharide
1. “Mono” means one
2. Examples include glucose,
fructose, galactose, and dextrose
3. Have a molecular formula of
C6H12O6
4. Structural formula is represented
as a hexagon (6-sides).
5. Are found in candy or sweets
(glucose) or in fruit (fructose)
Disaccharides-Double Sugars
• “di” means two
• Composed of two simple sugars
(monosaccharides) joined
together.
– Examples
• Maltose: made of glucose + glucose
• Lactose: made of glucose and galactose
(milk sugar)
• Sucrose: made of glucose and fructose
(table sugar)
Disaccharide – molecular formula
• The Formula is ALWAYS - C12H22O11
• If a disaccharide is composed of two monosaccharides, you should
add the molecular formulas together to get the new formula. DO IT
here.
C6H12O6
+ C6H12O6
---------------C12H24O12
• Do this formula match the one up top? No
• What is the difference? (subtract)
C12H24O12
- C12H22O11
-------------H2O
• What does this mean? When molecules combine, they lose a water.
Dehydration Synthesis
1. When smaller molecules are not used, they
join together through dehydration synthesis
2. The joining together of two molecules
1. An H is removed from one
2. An OH group is removed from another atom.
3. The H and the OH removed combine to form
water.
1. joined by a chemical bond . See example.
Polysaccharides – Complex Sugars
• “Poly” means many or 3 or more
• Theses are the sugars that become stored in the
body.
• Plants store them as starch or cellulose.
• Animals store them as glycogen.
• Hydrolysis - The opposite of dehydration synthesis.
– Molecules can be broken down by adding an H and an OH
back.
– Hydrolysis is used when the body is digesting or breaking
down large food molecules.
Carbohydrates Clip 2.10m
Glucose/glycogen conversion. 2004. Image. February 2011. <http://www.discoveryeducation.com/>.
Questions
1.
Why are carbohydrates necessary for the body?
1. Answer: They are the main energy source.
2.
What are the building blocks of carbohydrates?
1. Answer: Monosaccharides (simple sugars) –glucose, fructose,
etc, (C6H12O6)
3.
If we don’t use up the simple sugars, what happens to them?
1. Answer: They combine to form larger molecules by
dehydration synthesis
4.
If one doesn’t eat for a while, how can they obtain energy from
their body?
1. Answer: Break down complex carbs that are stored using
hydrolysis
Lipids (fats)
•
Facts
1. Lipids are ORGANIC molecules that include fats, oils, and
waxes.
2. They are our bodies SECONDARY energy source.
3. They are composed of the elements C, H, and O
4. They made up of a long carbon chain (many carbons in a
row)
5. Functions include:
1. insulation
2. cushioning of organs and joints
3. lubrication for skin
4. a component of our cell membranes (protection)
6. Formed when 3 fatty acids and 1 glycerol combine by
dehydration synthesis.
Lipid Formation Example
Saturated Fats –The bad ones
• These should make up no more than 30% of
your daily caloric intake.
– These are hard for the body to break down
(digest).
– All of the carbon atoms in the chain are single
bonded to hydrogen’s (they are said to be full or
saturated)
– These get stored in fatty tissue and can build up
around your organs and affect their function.
– They can get deposited on your blood vessel walls
as cholesterol.
• This causes an increase in blood pressure and a decrease
in blood flow.
• These tend to be solids at room temperature and
found in beef, cheese and milk.
• Movie Clips\Lipids__Fats_and_Oils0.37m.asf
Unsaturated fats
(the good ones)
• The body can digest these easier.
Omega-6
Omega-3
Monounsaturated
Fat
• Some of the carbonPolyunsaturated
atoms in the chainPolyunsaturated
are double Fat
Sources
Fat Sources
bonded meaning they
are not bondedSources
to as many
Nuts
Soybean
oil
Soybean oil
hydrogen’s
as
saturated
fats.
Vegetable oils
Corn oil
Canola oil
oil
Walnuts from
• Canola
Haveoilbeen found toSafflower
help remove
cholesterol
Olive oil
Flaxseed
blood
High
oleicvessel
safflowerwalls.
oil
Fish: trout, herring,
Sunflower oil
and salmon
• Avocado
Tend to be liquids at room temperature and found in
fish (omega oils), olive oil, and canola oil.
Questions
1. How are fats LIKE carbs?
– Answer: Contain C,H, and O; supply energy, organic
2. How are fats DIFFERENT than carbs?
1. Answer: Fats consist of long carbon chains, carbs are
hexagonal. Fats have no ratio of elements, carbs have a 2:1
ratio of H to O.
• What type of fat should you avoid and why?
• Answer: Saturated because they have many negative
health effects.
• What are the building blocks of lipids?
1. Answer: 3 fatty acids and 1 glycerol
Proteins
• Facts
– These are the largest and most complex organic
molecules.
– They contain the elements C, H, O, and N.
– Proteins are recognized by the presence of the
element N.
– Functions include maintaining body tissues, repairing
damaged tissues, growth of muscle tissue, act as
enzymes and hormones.
– Every protein has a unique shape. Proteins function
based on their shapes.
Structure of proteins
• The building blocks of
proteins are amino acids.
• All proteins are made up of
various combinations of
amino acids.
• There are only 20 different
amino acids in nature.
Amino Acids
• The basic structure of an
amino acid is:
– Amino group (NH2)
– carboxyl group (COOH)
attached to a central carbon.
– side chains are what makes
different amino acids (R).
• Movie Clips\Proteins1.47m.asf
Question
1. How many different R groups are there?
Answer: 20
1. How do we combine amino acids to make a
larger protein?
Answer: Dehydration synthesis (remove an H
and an OH)
Peptides
• Peptide Bond – When the carbon of one amino acid is joined to the nitrogen of
the other amino acid.
• Two amino acids joined together is called a dipeptide
• Three or more joined together is called a polypeptide.
Question
1.How do we break down a complex
protein (dipeptide or polypeptide)?
Answer: Hydrolysis; add an H to one
amino acid and an OH to the other
amino acid.
Enzymes -an important part of proteins
1. All enzymes are proteins.
2. The substance an enzyme acts on is called its
SUBSTRATE.
3. Most enzymes end in the suffix “ase”.
1. Examples: protease, lipase, lactase
4. Enzyme structure is not affected by a chemical
reaction.
1. They can be used over again
2. But may need to be replaced over time.
More about Enzymes
1. Enzymes are called CATALYSTS.
1. Speed up the rate of chemical reactions
2. Can be used to build a larger molecule
3. OR break one down.
2. They work similar to a lock and a key.
1. They work based on their shape
1.
the different possible combinations of amino acids create
different shaped proteins.
2. Each enzyme works on a specific substrate.
•
Movie Clips\Enzymes1.37m.asf
What affects the enzymes?
• High heat and strong acids or bases destroy
the enzymes.
• Reactions can be sped up by adding more
enzymes
Enzyme-Reaction Vocabulary
1. Enzyme-Substrate Complex - This is when the enzyme
and the substrate are actually joined together.
1. Only when this happens can the reaction proceed.
2. Coenzymes - these help an enzyme bond to its
substrate.
1. Vitamins are coenzymes.
Enzyme Reaction Steps
1. An enzyme and a SUBSTRATE are in the same area.
2. The enzyme grabs onto the substrate with a special area called
the ACTIVE SITE.
1.
2.
Area on the enzyme where the shape matches that of the substrate
The active site is the keyhole of the lock.
3. A process called CATALYSIS happens.
1.
2.
Catalysis is when the substrate is changed.
It could be broken down or combined with another molecule to make
something new.
4. The enzyme lets go.
1.
2.
When the enzyme lets go, it returns to normal, ready to do another reaction.
The substrate is no longer the same. The substrate is now called the PRODUCT.
Enzyme Breakdown Example
• Sucrose is a sweetener found in many candies.
– Carbohydrate disaccharide made up of glucose and fructose.
• When we eat sucrose, it must be digested or broken down
into smaller substances, which our cells can absorb.
• An enzyme (protein) called sucrase speeds up this chemical
reaction by breaking the chemical bond in sucrose, the
substrate.
Example of a Macromolecule
Monomer
polysaccharide (complex carbohydrate) monosaccharide (simple sugar)
fat (a lipid)
glycerol, fatty acid
protein
amino acid
nucleic acid
nucleotide