Module 02: Protein Structure and Function Flashcards
How many percentage do proteins make up a singular cell?
15%
What are the different functions of proteins?
(1) Enzymes (Catalytic)
(2) Structural
(3) Transport and Storage
(4) Signaling molecules and Receptors
(5) Defense
These links the amino acids of proteins
peptide bonds
This is the repeating sequence of the N-Ca-C-N-Ca-C-N-Ca-C… in the peptide bond.
Polypeptide backbone
The protein shape is determined by what?
The sequence of amino acids
The final shape is called the _____________and has the lowest free energy possible (stable)
Conformation
This is the process of unfolding the protein, manifested by coagulation.
Denaturation
Which agent can cause denaturation?
heat, pH or chemical compounds like alcohol, urea, acids and bases
These protein turns like a spiral – fibrous proteins.
Alpha helix
This protein folds back on itself as in a ribbon –globular proteins
Beta sheets
Where is alpha-helix located?
The human hair, nails, and skin
These soluble in water and have compact shape like a ball with irregular surfaces.
Globular Proteins
What are some examples of globular proteins?
(1) Enzymes
(2) Immunoglobins
(3) Transport molecules like myoglobin and hemoglobin
(4) Hormones
These are insoluble in water and usually span a long distance in the cell. This has a 3-D structure is usually long and rod shaped
Fibrous proteins
What function does fibrous proteins have?
Structural Function
What are some examples of fibrous proteins?
(1) Collagen
(2) Keratin
(3) Silk Fibroin
This is composed of of 2 a-helices
Coiled Coil
This is composed of pair of coiled coils
Protofilament
This is composed of four coiled protofilaments
Microfilament
This type of keratin is the basic structural unit is the alpha helix and is seen in humans.
Alpha keratin
Where is the alpha keratin found?
wools, hair, skin and nails
What is role of alpha keratin?
To provide structural stability
This form of keratin is present in birds and reptiles and is known to be rich in beta sheet structures
Beta keratin
Where is b-keratin found?
Found in hard tissues like feathers, horns, claws and hooves, beaks and scales