Lecture 3: Proteins 1 Flashcards
(7 cards)
What are the 7 functions and structures Proteins form?
- Enzymes: Biological Catalysts (Facilitate Chemical Reactions in the Body at reasonable temperatures and pHs
- Defense: Cell Surface Receptors
- Transport: Hemoglobin and Membrane Trasport Proteins
- Support: Keratin in hair, fibres in blood clots and collagen (Makes up connective tissues)
- Motion: Actin, Myosin (Involved in muscles system)
- Regulation: Hormones and Transcription factors (Proteins that regulate DNA transcription and regulation)
- Storage: Calcium and Iron Bind to Specific Proteins to exit the blood but stay in body
What is contained in an amino acid group?
Contain amino (H_2N) and acidic carboxyl (COOH) groups. Functional side (-R) group. Amino acids are chiral: D or L* ( (D is less common form) L is most common form)
How do peptides get formed?
Dehydration Synthesis where the OH and H group form a covalent bond
What can influence a Protein’s shape?
Hydrogen Bonds Covalent Disulphide Bridges Ionic Bonds Van Der Waals Attractions The polarity of the amino acids
What are the 4 Levels of Structure of Proteins?
Primary: Straight Line
Secondary: Folds (Beta Sheets) or Spirals (Alpha Helix)
Tertiary: Many folds or spirals but together (Hydrophobic exclusion. Disulphide bonds. Stability: Depends on how well its interior fits together.)
Quaternary: Many Tertiary Proteins put together (Hemoglobin: Two Alpha-chain subunits two beta-chain subunits)
What are Motif Structural Elements?
Similarities between otherwise; dissimilar proteins, can often be used to predict the function
(Beta-sheet, alpha-helix, beta-sheet is called a Rossman fold and creates a fold or crease in a protein)
Helix-turn-helix: two α helices separated by a bend.
What are structural Domains?
Fractional Units within larger subunits
They perform different parts of a protein’s function. Many help to fold proteins properly
Can correspond to the structure of the gene that encoded them
