4 Proteins in Foods Free Online FlashCards

What is a protein’s primary structure?

The amino-acid sequence of a protein is its primary structure.

How do globular proteins differ from milk caseins?

Globular proteins, such as egg-white and whey proteins, are compact and folded; milk caseins are more flexible and form larger assemblies.

What happens to a protein during denaturation?

Denaturation changes a protein’s folded structure, usually without breaking most peptide bonds, so its amino-acid chain remains intact.

What is protein gelation?

Gelation occurs when proteins form a connected three-dimensional network that traps water, producing a soft or semi-solid food.

How do proteins help stabilize oil-in-water emulsions?

Proteins can stabilize oil-in-water emulsions by attaching at the oil–water boundary and coating droplets, which helps slow them from merging.

What forms a protein’s secondary structure?

Local folds, such as helices and sheets, make up a protein’s secondary structure.

What is a protein’s tertiary structure?

Tertiary structure is a protein’s overall three-dimensional shape.

What is a protein’s quaternary structure?

Quaternary structure is the association of multiple protein chains.

How do denaturation and aggregation differ?

Denaturation unfolds or changes protein structure; aggregation brings protein molecules together. They are related but distinct processes.

Why does heated egg white become opaque and firm?

Heating unfolds egg-white proteins, which then aggregate into an opaque, firm structure.

How can heating produce a protein gel?

Heating unfolds proteins, allowing them to form a network through interactions such as hydrophobic attraction and, in some systems, disulfide bonds.

What can excessive aggregation do to a protein gel?

If aggregation is too rapid or extensive, the network can become coarse and squeeze out water instead of forming a smooth gel.