PRESENTATION OUTLINE
Agenda
- Proteins
- Lipids
- DNA
- (these are all organic compounds)
Proteins are made up of amino acids.
When amino acids bind together they form a chain called a polypeptide.
A protein has at least one polypeptide chain.
Four Levels of Protein Structure
- Sequence of amino acids
- Pleated sheet or alpha helix
- Attractions between secondary structures
- More than one amino acid chain
Complex structures give proteins unique properties.
Functions of Proteins
- Structural
- Transport (like hemoglobin)
- Signals
- Enzymes
- Antibodies
Dietary proteins are broken down into amino acids when food is digested.
Why do we have to eat protein?
Humans can only synthesize 12 of the 20 common amino acids.
The 8 remaining amino acids are called essential amino acids because they must be consumed.
Proteins can be broken down to provide energy.
Fats and oils are examples of lipids. Lipids store energy.
Lipids are made of repeating units of fatty acids.
Carbon atoms in saturated fatty acids are bound to as many hydrogens as possible, forming straight chains.
Carbon atoms of unsaturated fatty acids are not bound to as many hydrogen atoms, and the chains are bent.
Saturated fats are solid at room temp, but unsaturated fats are liquids.
Other types of lipids
- Triglycerides
- Phospholipids (in cell membranes!)
- Steroids
Essential fatty acids like omega-3 and omega-6 must be consumed.
A nucleic acid is built of small units called nucleotides.
Nucleotides bind together to form polynucleotide chains such as RNA.
Each nucleotide is composed of
- Sugar
- Phosphate group
- Nitrogen base
The nitrogen base sticks out from the sugar-phosphate backbone.
Nitrogen Bases
- Adenine
- Thymine (Uracil)
- Cytosine
- Guanine
- Form complementary base pairs
DNA molecules form a double helix, which is very strong.