Biochemistry for Psychology Reviewer (2nd • Conjugated Proteins
- Simple proteins linked with non-protein groups.
Semester)
1. Chromoprotein – proteins linked w/ a
Protein Classification colored compound.
Example: hemoglobin in blood
► Classification of Proteins According to Shape 2. Glycoproteins – proteins linked w/ a
carbohydrate.
Fibrous Protein Globular Protein
Consists of long, parallel Consists of coiled and Example: mucin in saliva
polypeptide chains folded polypeptide 3. Phosphoprotein – protein linked w/ H3PO4.
forming helical structures chains forming spherical Example: casein in milk; vitellin in egg yolk
or pleated sheets shape 4. Nucleoproteins – proteins linked w/ nucleic
Insoluble in water Soluble in water acids.
The structures is stable The structures is unstable Example: nuclein in nuclei of cells
Plays a major role in Takes part in metabolite 5. Lipoproteins – proteins linked w/ fatty acid.
mechanical and and chemical processes
structural functions ► Classification of Proteins According to Nutritive
Example: Keratin and Example: Enzymes and Value
collagen haemoglobin 1. Complete or adequate proteins- contain all
essential amino acids.
• Keratin, collagen, elastin Examples: proteins in milk & egg.
2. Incomplete or inadequate proteins – lacks one or
more of the essential amino acids.
Examples: gelatin and protein in corn and flour.
► Classification of Proteins According to Function
1. Catalytic action – enzymes
2. Regulatory – hormones such as insulin
3. Antibody proteins – for defense against foreign
bodies
• Enzymes, peptide hormones, hemoglobin 4. Transport- hemoglobin; serum albumin
5. Buffer – hemoglobin
6. Structural – collagen in tendons, keratin in skin,
hair, nails, wool, horn & feathers; elastin in arteries
& skin
7. Blood coagulant – fibrin
8. Germicidal – anti-tumor- peptide antibiotic such as
Gramicidin A
► Classification of Proteins According to Composition
• Simple Proteins
- Give only α-amino acids upon hydrolysis.
1. albumin in egg
2. globulins – myosin in muscle
3. glutelins – glutenin in wheat & oryzenin in
rice
4. prolamines – zein in corn, gliadin in wheat,
hordein in barley
5. albuminoids – elastin in tendons, keratin in
hair, fibrosin in silk
, ► Building Proteins ► Primary Structure
• Peptide bonds - The primary structure is the sequence of amino
- Linking NH2 of one amino acid to COOH of acids that are linked together. The linear
another structure is called a polypeptide.
- C–N bond
- N terminus – C terminus
- For example, the amino acid sequence in
glutathione, a biologically important tripeptide
is glu-cys-gly.
► Protein Structure and Function
- Function depends on structure
- 3-D structure – twisted, folded, coiled into
unique shape
- The primary structure determines the folding of
the polypeptide to give a functional protein.
- Polar amino acids (acidic, basic and neutral) are
hydrophilic and tend to be placed on the
outside of the protein.
- Non-polar (hydrophobic) amino acids tend to be
placed on the inside of the protein.
- Simple proteins linked with non-protein groups.
Semester)
1. Chromoprotein – proteins linked w/ a
Protein Classification colored compound.
Example: hemoglobin in blood
► Classification of Proteins According to Shape 2. Glycoproteins – proteins linked w/ a
carbohydrate.
Fibrous Protein Globular Protein
Consists of long, parallel Consists of coiled and Example: mucin in saliva
polypeptide chains folded polypeptide 3. Phosphoprotein – protein linked w/ H3PO4.
forming helical structures chains forming spherical Example: casein in milk; vitellin in egg yolk
or pleated sheets shape 4. Nucleoproteins – proteins linked w/ nucleic
Insoluble in water Soluble in water acids.
The structures is stable The structures is unstable Example: nuclein in nuclei of cells
Plays a major role in Takes part in metabolite 5. Lipoproteins – proteins linked w/ fatty acid.
mechanical and and chemical processes
structural functions ► Classification of Proteins According to Nutritive
Example: Keratin and Example: Enzymes and Value
collagen haemoglobin 1. Complete or adequate proteins- contain all
essential amino acids.
• Keratin, collagen, elastin Examples: proteins in milk & egg.
2. Incomplete or inadequate proteins – lacks one or
more of the essential amino acids.
Examples: gelatin and protein in corn and flour.
► Classification of Proteins According to Function
1. Catalytic action – enzymes
2. Regulatory – hormones such as insulin
3. Antibody proteins – for defense against foreign
bodies
• Enzymes, peptide hormones, hemoglobin 4. Transport- hemoglobin; serum albumin
5. Buffer – hemoglobin
6. Structural – collagen in tendons, keratin in skin,
hair, nails, wool, horn & feathers; elastin in arteries
& skin
7. Blood coagulant – fibrin
8. Germicidal – anti-tumor- peptide antibiotic such as
Gramicidin A
► Classification of Proteins According to Composition
• Simple Proteins
- Give only α-amino acids upon hydrolysis.
1. albumin in egg
2. globulins – myosin in muscle
3. glutelins – glutenin in wheat & oryzenin in
rice
4. prolamines – zein in corn, gliadin in wheat,
hordein in barley
5. albuminoids – elastin in tendons, keratin in
hair, fibrosin in silk
, ► Building Proteins ► Primary Structure
• Peptide bonds - The primary structure is the sequence of amino
- Linking NH2 of one amino acid to COOH of acids that are linked together. The linear
another structure is called a polypeptide.
- C–N bond
- N terminus – C terminus
- For example, the amino acid sequence in
glutathione, a biologically important tripeptide
is glu-cys-gly.
► Protein Structure and Function
- Function depends on structure
- 3-D structure – twisted, folded, coiled into
unique shape
- The primary structure determines the folding of
the polypeptide to give a functional protein.
- Polar amino acids (acidic, basic and neutral) are
hydrophilic and tend to be placed on the
outside of the protein.
- Non-polar (hydrophobic) amino acids tend to be
placed on the inside of the protein.
