Learning Theory Pyramid and Proteins

Learning Theory Pyramid

• Traditional learning methods are passive, with low retention of information.
• Lecture-based learning has the lowest retention rate, with only 5% average retention.
• Reading material has slightly better retention (10%)
• Moving up the pyramid, using audio-visual aids increases retention rate further, up to 20%.
• Demonstrations increase average retention to 30%.
• Discussion groups increase retention to 50%.
• Practicing through doing boosts retention to 75%.
• Teaching others/immediate use has the highest retention rate (90%).
• Active learning strategies are most effective for knowledge retention.

Proteins

• Proteins are chains of amino acids linked by peptide bonds.
• The specific amino acid sequence (amino acid sequence, a.a.) dictates a protein's structure and function.
• Amino acids have a variable side chain ("R" group).
• A typical amino acid contains an amino group ("N-terminus") and a carboxyl group ("C-terminus").
• Twenty different amino acids (a.a.) exist.

Amino Acids

• Amino acids can be categorized as hydrophobic, hydrophilic, or electrically charged, based on their properties.
• Nine amino acids are essential for the human body and must be ingested.
• Proteins are often amphiphilic (having both non-polar and polar characteristics) because they contain both polar and non-polar amino acids.

Essential Amino Acids

• List of essential amino acids with potential food sources are presented.

Peptide Synthesis

• Peptide bonds form between amino acids through dehydration synthesis, releasing a water molecule.
• A dipeptide is formed by joining two amino acids.

Peptide Classification

• Peptides are chains formed by two or more amino acids.
• Dipeptides contain two amino acids.
• Tripeptides contain three amino acids.
• Oligopeptides contain fewer than 10 to 15 amino acids.
• Polypeptides contain more than 15 amino acids.
• Proteins have more than 100 amino acids.

Protein Structures

• Proteins fold into three-dimensional structures.
• Protein structure is classified into four levels: primary, secondary, tertiary, and quaternary.

1° Protein Structure

• Linear sequence of amino acids held together by peptide bonds.
• Sequence variation leads to diverse protein structures and functions.

2° Protein Structure

• Amino acid chain folds into alpha-helices or beta-pleated sheets.
• Stabilized by hydrogen bonds between amino acid backbones.

3° Protein Structure

• Three-dimensional folding of secondary structures.
• Stabilized by interactions between R groups (e.g. hydrophobic interactions, disulfide bridges, ionic bonds).

4° Protein Structure

• Multiple polypeptide chains assemble into a larger complex.
• Stabilized by interactions between polypeptide chains (e.g. hydrogen bonds).

Sickle Cell Anemia

• A genetic mutation in hemoglobin, a protein, leads to sickle cell anemia.
• Changing one amino acid in the sequence causes a change in the protein's structure.
• This mutated hemoglobin causes red blood cells to become misshapen and block blood flow.

Protein Denaturation

• Denaturation is the unfolding of a protein's structure, resulting in a loss of its biological function.
• Factors that cause denaturation are extreme changes in temperature or pH.
• The unfolding of a protein is reversible or irreversible depending on the severity of denaturation.

Conjugated Proteins

• Proteins that combine with a non-protein component (prosthetic group) for function.
• Hemoglobin is an example where heme is the prosthetic group.

Protein Functions

• Proteins have diverse roles in life processes.
• These roles range from structural support/movement, communication, recognition and protection to transport and catalysis.

Dr. Marie Maynard Daly

• First African-American woman to earn a Ph.D. in chemistry.
• Made significant contributions in the understanding of macromolecules like proteins and amino acids.