Quiz on Proteins

Proteins are the _______ and most _______ molecule of all food substances.

• longest, complex

• shortest, simple

• smallest, complex

• longest, simple

Answer explanation

Proteins are the longest and most complex molecules among food substances, consisting of long chains of amino acids that fold into intricate structures, making them essential for various biological functions.

Which of the following is the complete list of components which make up amino acids?

• Nitrogen, carbon, phosphorus and sulfur

• Carbon, nitrogen, oxygen and phosphorus

• Sulfur, hydrogen, nitrogen, and either carbon, oxygen or phosphorus

• Carbon, hydrogen, oxygen, and either nitrogen, sulfur or phosphorus

Answer explanation

Amino acids are composed of carbon, hydrogen, oxygen, and either nitrogen, sulfur, or phosphorus. The correct choice includes all essential elements, making it the complete list of components for amino acids.

Amino acids are linked by _______ bonds and held together by _______ bonds.

• hydrogen, peptide

• peptide, hydrogen

• ionic, covalent

• covalent, ionic

Answer explanation

Amino acids are linked by peptide bonds, which are a type of covalent bond. They are held together in a protein structure by hydrogen bonds, which stabilize the overall shape of the protein.

Proteins are a chain of _______ acids linked by _______ bonds.

• nucleic, ionic

• amino, peptide

• fatty, covalent

• nucleic, peptide

Answer explanation

Proteins are made up of amino acids, which are linked together by peptide bonds. This is the fundamental structure of proteins, making 'amino' and 'peptide' the correct terms to fill in the blanks.

Protein synthesis is the process of amino acids determining specific DNA sequences in order to create varying proteins.

• True

• False

• Sometimes true

• Always true

Answer explanation

The statement is false because protein synthesis involves ribosomes translating mRNA sequences into amino acids, not the other way around. Amino acids are determined by mRNA, which is transcribed from DNA.

During transcription, RNA _______ helps to create a copy of DNA, called _______.

• polymerase, mRNA

• mRNA, polymerase

• DNA, transcription

• transcription, DNA

Answer explanation

During transcription, RNA polymerase synthesizes a complementary RNA strand from the DNA template, resulting in the formation of mRNA. Thus, the correct answer is 'polymerase, mRNA'.

Primary structure occurs in a _______.

• Three-dimensional pattern

• Linear pattern

• Globular pattern

• Fibrous pattern

Answer explanation

Primary structure refers to the linear sequence of amino acids in a protein. This linear pattern is crucial as it determines the protein's overall structure and function.

Denaturation is the loss of __________ during a process which disrupts the secondary and tertiary structures of a protein.

• Mass

• Volume

• Biological activity

• Physiological conditions

Answer explanation

Denaturation disrupts the secondary and tertiary structures of a protein, leading to the loss of its biological activity. This means the protein can no longer perform its intended functions, making 'biological activity' the correct answer.

Coagulation begins around 160°F (71°C) and is complete at 180°F (82°C).

• True

• False

Answer explanation

The statement is false because coagulation typically begins at lower temperatures, around 140°F (60°C), and is complete at higher temperatures, but not specifically at 180°F (82°C).

What process creates the texture of bread?

• Emulsions

• Foams

• Coagulation

• Syneresis

Answer explanation

Coagulation is the process where proteins in the dough denature and form a network, contributing to the bread's structure and texture. This is essential for creating the desired crumb and crust in baked bread.