Biology Chapter 3 B Flashcards

Proteins are polymers of _____

What type of bond joins the monomers in a protein's primary structure?

The secondary structure of a protein results from

Tertiary structure is not directly dependent on

At which bond would water need to be added to achieve hydrolysis of the dipeptide?

Some regions of a polypeptide may coil or fold back on themselves. This is called _____, and the coils or folds are held in place by _____.

What makes one amino acid different from another?

Which bonds maintain the primary structure of a protein?

The a-helix and B-pleated sheet are examples of which level of protein structure?

What disruption occurs when lactase is transferred to pH 5?

Interactions between the side chains (R groups) in a polypeptide are most important in stabilizing which of the following?

What would changing a single amino acid in a protein of 325 amino acids do?

Which of the following statements is an accurate description of proteins?

What could happen if a genetic mutation replaced a hydrophobic amino acid in a polypeptide with a hydrophilic one?

Which level of protein structure is a characteristic of some, but not all, proteins?

Protein Structure and Function

Proteins are made from polymers of amino acids.
Peptide bonds link monomers in a protein's primary structure.
The secondary structure of proteins, including α-helices and β-pleated sheets, is stabilized by hydrogen bonds.
Tertiary structure relies primarily on interactions among side chains (R groups) and not on peptide bonds.
Hydrolysis of dipeptides restores amino acids, necessitating the addition of water at the peptide bond.
Regions of a polypeptide can coil or fold due to secondary structure, which is also stabilized by hydrogen bonds.

Amino Acids and Variability

There are 20 different amino acids, distinguished by unique side chains (R groups) attached to an α carbon.
Peptide bonds specifically maintain the primary structure of a protein.
Altering a single amino acid in a protein can change its primary structure and may sometimes affect its biological function and tertiary structure.

Enzyme Activity and pH Dependency

Lactase, a single polypeptide enzyme, hydrolyzes lactose into monosaccharides, functioning optimally at pH 6.
Transferring lactase to pH 5 significantly diminishes enzyme activity, likely due to disruptions in secondary and tertiary structures.

Structural Levels of Proteins

Interactions between side chains are crucial for stabilizing the tertiary structure of proteins.
The primary structure refers to the sequence of amino acids defined by the genetic code in DNA.
Quaternary structure is present in some proteins, involving the assembly of multiple polypeptides.

Impact of Mutations

A mutation causing a hydrophobic amino acid to convert to a hydrophilic one can disrupt protein interactions leading to altered protein shape and function.

Test your knowledge on proteins with these flashcards from Biology Chapter 3 B. Each card covers essential concepts such as amino acids, peptide bonds, and protein structures. Ideal for quick revision or in-depth understanding of protein biology.