Macromolecules
Carbohydrates, Lipids, Proteins, and Nucleic Acids
Macromolecules
• Macromolecules are relatively large
compounds compared to the size of the atom.
• There are four major macromolecules that are
essential to life for humans.
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
Macromolecules in
Life
• Three of the four macromolecules should be
familiar as they are the main nutrients listed on
nutrition labels.
• Carbohydrates, lipids (fats), and protein are
part of everyday conversations.
• Nucleic acids are the building blocks of DNA
and are rarely discussed outside of science
class. Though they are incredibly vital to your
existence.
Carbohydrates
• Carbohydrates consist of three different atoms
• Hydrogen
• Carbon
• Oxygen
Use of Carbohydrates
• Carbohydrates are the body's main source of
quick energy.
• 1 gram of carbohydrate will release 4 calories
of energy when broken down by the body.
This means that for every gram of
carbohydrate you eat, you will be "consuming"
four calories.
• Carbohydrate food sources
• Bread, pasta, rice, potatoes, sugar, and
wheat
Classes of
Carbohydrates
• Monosaccharides
• Disaccharides
• Polysaccharides
Monosaccharides
• The prefix "mono" means one
• A monosaccharide is a molecule that have
one saccharide molecule.
• These are the simplest saccharides and
include:
• Glucose
• Galactose
• Fructose - the sugar found in fruit
Disaccharides
• The prefix "di" represents the number two
• A disaccharide is a molecule that has two
saccharide molecules joined together
• Disaccharides are more complex and include:
• Maltose
• Lactose - the sugar found in milk
• Sucrose
Polysaccharides
• The prefix "poly" means many
• A polysaccharide is a molecule that has three
or more saccharide molecules joined together
• Polysaccharides are even more complex and
include: Cellulose, Starch, Chitin, and
Glycogen
Polysaccharides
• Cellulose - the substance that makes up the
cell wall of a plant
• Starch - the substance found in potatoes and
pasta
• Chitin - the substance that makes up the
exoskeleton in arthropods such as crabs and
lobsters
• Glycogen - a energy source for animals
stored in the liver and muscles
Lipids
• Lipids consist of three different atoms
• Hydrogen
• Carbon
• Oxygen
Use of Lipids
• Lipids serve many functions
• Long term energy storage.
• 1 gram of lipid will release 9 calories of energy
when broken down by the body. This means
that for every gram of carbohydrate you eat,
you will be "consuming" nine calories.
• Structural - makes up parts of cells
• Living system regulation - act as hormones in
the body.
Properties of Lipids
• Lipids are very diverse and are grouped
together because they are hydrophobic.
• Most lipids have a similar structure
• A glycerol molecule attached to a fatty acid
Fatty Acids
• There are two forms of fatty acids. These
forms of the fatty acids are what nutritionists,
commercials, and doctors are talking about
when they discuss "good fats" and "bad fats."
• Saturated
• Unsaturated
Saturated Fats
• The carbon atoms share only two elections
between them. The sharing of two electrons
only is called a single bond.
• This type of fat is often found in animals
and has been linked to major
cardiovascular disease
• The type of fat is usually solid at room
temperature
• Butter and visible fat on meat
Unsaturated Fats
• Some carbon atoms share four elections
between them. The sharing of four electrons
is called a double bond.
• This type of fat is often found in plants
and are considered healthy
• The type of fat is usually liquid at room
temperature
• Olive oil, canola oil, and sunflower oil
Steroids
• This form of lipid has a different form than the
previous types
• Instead of fatty acid chains, steroids are made
of four fused rings.
• Examples include
• Cholesterol
• Testosterone
• Estradiol
Proteins
• Lipids consist of several different atoms
• Hydrogen
• Carbon
• Oxygen
• Nitrogen
• Sulfur
• Phosphorus
Use of Proteins
• Proteins serve many functions
• Growth and repair of cells.
• Cell communication
• Protection
• Promoting chemical reactions
Use of Proteins
• They also store energy, but in a form that is
not as useful as lipids and carbohydrates
• 1 gram of protein will release 4 calories of
energy when broken down by the body.
This means that for every gram of protein
you eat, you will be "consuming" four
calories.
Properties of proteins
• Made of small building blocks called amino
acids
• Only twenty known amino acids that join in
various combinations to create different
protein.
• The shape of a protein determines its function
and the job it performs.
• Four levels of protein structure
• Primary, secondary, tertiary,
quaternary
Primary Structure
• This is the sequence of amino acids that make
up the protein.
• Alteration in the sequence of amino acids
can be fatal or have serious
consequences.
• Sickle cell anemia is caused when an
amino acid is accidentally replaced with
another in the hemoglobin protein.
Secondary Structure
• This structure is caused by the hydrogen
bonding that can occur between the amino
acids in the sequence.
• Two shapes can for
• Alpha helix
• Beta pleated sheets
Tertiary Structure
• This is the three dimensional structure that a
protein forms due to interactions between
different parts of the protein.
• The tertiary shape determines the protein's
specific function
Quaternary Structure
• This structure is formed by the interaction
between two or more tertiary proteins.
• Hemoglobin, a protein found in blood, has 4
protein chains that interact.
Nucleic Acids
• There are two forms of nucleic acids
• RNA (ribonucleic acid)
• DNA (deoxyribonucleic acid)
Use of Nucleic Acids
• Nucleic acids carry all genetic information.
• DNA is the molecule from which all hereditary
traits are passed on.
Properties of Nucleic
Acids
• Nucleic acids are made of 5 different bases, a
sugar and a phosphate group.
• 5 different nitrogen bases:
• Adenine
• Cytosine
• Guanine
• Thymine (in DNA only)
• Uracil (in RNA only)
Properties of Nucleic
Acids
• Two types of sugars
• Ribose sugars in RNA
• Deoxyribose sugars in DNA
• Phosphate Group
• A covalently bonded group of phosphorus
and oxygen.