L4 Exam Questions - Flashcards Overview
Key Concepts
Protein Structure
- Quaternary Structure: Term used to describe a protein structure made of two or more polypeptide chains.
Amino Acids and Peptides
- Dipeptide: Consists of two amino acids joined by a peptide bond.
- Similarities:
- Can be broken down through a hydrolysis reaction.
- Both are alpha glucose molecules.
- Differences:
- Chains may be branched or unbranched.
- Peptide Bond Formation:
- Formed through a condensation reaction between amine and carboxyl groups.
Polypeptide Secondary Structure
- Produced by hydrogen bonds between amino acids.
- Occurs between NH group of one amino acid and C=O group of another.
- Can form pleated sheets or a helix.
Differences in Protein Structure
- Two proteins with the same number and type of amino acids can have different tertiary structures due to:
- Different amino acid sequences (primary structure).
- Ionic, hydrogen, and disulfide bonds forming in different locations.
Chemical Elements in Biochemistry
- Nitrogen: Chemical element found in all amino acids that is not present in triglycerides.
Chemical Processes
- Condensation Reaction: Process involved in forming linkages like peptide bonds.
Bond Formation
- Dipeptide and Water: Formed when two amino acids join.
- Ester Bond: Type of bond formed between two amino acid molecules.
Changes in Protein Structure
- Change in primary structure of a globular protein affects its three-dimensional structure due to:
- Changes in amino acid sequence.
- Alterations in tertiary structure leading to bonds in different locations.
Keratin Structure
- Quaternary Structure Evidence: More than one polypeptide chain within the molecule.
- Sulphur-Containing Amino Acids:
- Form chemical bonds between sulphur-containing groups (R-groups).
- Disulphide bonds provide strength by binding chains to each other.
- Differences in Keratin Properties:
- Due to variations in amino acid numbers and sequences, resulting in different bond placements and shapes.
Additional Resources
- Explore other flashcard sets and study guides on this topic at Quizlet.
These notes capture the essence of the L4 exam questions flashcards and provide a foundation for understanding protein structures, peptide bonds, and variations in protein properties.