Question

Classify each of the following proteins according to its function: a. hemoglobin, oxygen carrier in the blood b. collagen, a major component of tendons and cartilage c. keratin, a protein found in hair d. amylases that hydrolyze starch

Short answer

Hemoglobin: transport protein; Collagen: structural protein; Keratin: structural protein; Amylases: enzymatic protein

Step-by-step solution

- Identify the function of hemoglobin

Hemoglobin is a protein that carries oxygen in the blood. Proteins that transport molecules are classified as transport proteins.

- Identify the function of collagen

Collagen is a major component of tendons and cartilage, providing structural support. Therefore, collagen is classified as a structural protein.

- Identify the function of keratin

Keratin is a protein found in hair and also provides structural support. Hence, keratin is classified as a structural protein.

- Identify the function of amylases

Amylases are enzymes that hydrolyze starch. Enzymes are proteins that catalyze biochemical reactions, so amylases are classified as enzymatic proteins.

Key concepts

Transport Proteins

Transport proteins play a crucial role in moving molecules across cell membranes and within the body. One of the primary examples is hemoglobin.
Hemoglobin is an essential transport protein as it carries oxygen from the lungs to the body's tissues.
If hemoglobin didn't exist, our cells wouldn't receive the oxygen they need to function.
Other examples of transport proteins include:

• Albumin - Transports fatty acids
• Transferrin - Transports iron

These proteins ensure that vital substances are delivered where they are needed in the body.

Structural Proteins

Structural proteins provide support and shape to cells and tissues. Collagen and keratin are two well-known examples.
Collagen is a major component of tendons and cartilage, giving strength and structure.
Without collagen, our connective tissues would lack resilience and durability.
Similarly, keratin is found in hair, nails, and the outer layer of skin.
Keratin makes these structures tough and resistant to damage.
Other structural proteins include:

• Actin - Part of the cytoskeleton that helps cells maintain their shape
• Elastin - Adds elasticity to tissues like skin and blood vessels

Enzymatic Proteins

Enzymatic proteins are catalysts for biochemical reactions in the body. Amylases are a type of enzymatic protein that break down starch into sugars.
This process is vital for digestion and nutrient absorption.
Without enzymes like amylases, our bodies would not be able to convert food into energy efficiently.
Other important enzymatic proteins include:

• Proteases - Break down proteins into amino acids
• Ligases - Join two molecules together
• Polymerases - Assist in DNA replication

These enzymes accelerate reactions, making them happen faster than they would naturally.

Biological Macromolecules

Proteins are a type of biological macromolecule, which are large, complex molecules crucial for life.
Biological macromolecules include proteins, nucleic acids, carbohydrates, and lipids.
All proteins, including transport, structural, and enzymatic proteins, are made up of long chains of amino acids.
Amino acids are the building blocks of proteins, and the sequence in which they are arranged determines the protein's function.
Proteins can take on various shapes, allowing them to perform diverse roles in the body.
Other types of biological macromolecules include:

• DNA - Stores genetic information
• RNA - Translates genetic information into proteins
• Polysaccharides - Serve as energy sources and structural components

Understanding these macromolecules is key to studying biochemistry and biology.