- Simple protein refers to protein that consists of only amino acids and does not contain any other substances. Example: collagen.
- Conjugated protein is a protein that contains non-protein materials called prosthetic groups. Example: haemoglobin.
- The globular protein is a polypeptide chain with tertiary or quaternary structures. It is tightly coiled and folded into a spherical shape. Examples: enzymes, antibodies and some hormones.
Define simple protein, conjugated protein and the globular protein
Amino acids are amphoteric molecules. Explain this statement.
- Amphoteric molecules can act both as a base and an acid.
- Amino acids have both acidic (carboxyl) and basic amino groups.
- At high concentrations of hydrogen ions, the negatively charged carboxyl group will accept protons and become uncharged and the overall charge of the amino acids becomes positive.
- At low concentration of hydrogen ions, the positively charged amino group loses its proton and the overall charge of molecule becomes negative.
State factors that can cause the denaturation of proteins
- Heat or radiation
- Strong acids and alkalis
- High salt concentration and heavy metals
- Detergent and organic solvents
- Mechanical force
Compare between fibrous protein and globular protein
Similarities:
Both are polypeptides.
Differences:
STPM Chemistry Syllabus 3rd Term
Chapter 14: Introduction to
Organic Chemistry
14.1 Bonding of the carbon
atoms: the shapes of ethane, ethane, ethyne and benzene molecules
14.2 General, empirical,
molecular and structural formulae of organic compounds
14.3 Functional groups:
classification and nomenclature
14.4 Isomerism: structural
and stereoisomerism
14.5 Free radicals,
nucleophiles and electrophiles
14.6 Molecular structure and
its effect on physical properties
14.7 Inductive and resonance
effect
Chapter 15: Hydrocarbons
15.1 Alkanes
15.2 Alkenes
15.3 Arenes
Chapter 16: Haloalkanes
Chapter 17: Hydroxy
Compounds
17.1 Introduction to hydroxy
compounds
17.2 Alcohols
17.3 Phenols
Chapter 18: Carbonyl
Compounds
Chapter 19 Carboxylic Acids
and their derivatives
19.1 Carboxylic acid
19.2 Acyl chlorides
19.3 Esters
19.4 Amides
Chapter 20: Amines, Amino
Acids and Proteins
20.1 Amines
20.2 Amino acids
20.3 Proteins
Chapter 21: Polymers