AQA AS Biology: Proteins and Enzymes Structure and Function Quiz

Proteins have diverse functions and roles in the body, including structural support, enzymatic activity, hormone regulation, and immune defense.

There are a total of 20 standard amino acids that are used to build proteins in living organisms.

The correct answer is the 'R' Group, which is the variable part of the amino acid molecule and determines the specific properties of each amino acid.

Deamination is the process of removing the amino group from the amino acid, not adding it. It does not occur in muscles or lungs. Excess amino acids cannot be stored due to their toxic nature when the amino group is present in excess.

When amino acids are bonded together, a peptide bond is formed which is a type of covalent bond.

When two amino acids join together through a peptide bond, they form a dipeptide. A monopeptide would imply a single amino acid, while tripeptide and polypeptide refer to molecules formed from three and multiple amino acids, respectively.

A polypeptide is a polymer of amino acids linked by peptide bonds. Monosaccharide is a simple sugar, lipid is a group of naturally occurring molecules that include fats, waxes, and steroids, and nucleotide is the basic building block of nucleic acids like DNA and RNA.

Non-essential amino acids are termed so not because they are not important, but because the body can synthesize them from other amino acids. They are still crucial for protein synthesis.

A dipeptide molecule is formed by the condensation reaction between the carboxyl group of one amino acid and the amino group of another amino acid, resulting in the formation of a peptide bond.

Polypeptides and proteins are actually synthesized on ribosomes, which can be found in both prokaryotic and eukaryotic cells.

The secondary structure of a protein is specifically determined by hydrogen bonds, not by the number of amino acids, DNA or RNA structure, or the overall 3-dimensional shape. The two main types are alpha helix and beta pleated sheet.

The tertiary structure refers to the three-dimensional conformation of a protein resulting from interactions between amino acid side chains, forming hydrogen bonds, hydrophobic interactions, disulphide bridges, and ionic bonds. It is crucial for the proper function of proteins.

The quaternary structure refers to how multiple polypeptide chains come together to form a functional protein complex.

Proteins are large molecules made up of amino acids and play vital roles in various biological processes. Haemoglobin is a protein found in red blood cells that carries oxygen, while collagen is a structural protein found in connective tissues.

Proteins have an amino group at one end and an acid group at the other because they are composed of amino acids joined in a specific sequence. This structure allows for the amino group of one amino acid to join with the acid group of the next amino acid, forming peptide bonds and creating the protein chain.

The correct answer highlights the key similarities and differences between Collagen and Haemoglobin in terms of their protein structure, function, and composition. The incorrect answers provide contrasting statements that are untrue, thereby emphasizing the unique characteristics of Collagen and Haemoglobin.

Cellulose and collagen are both fibrous molecules that provide structural support in organisms. They are strengthened by hydrogen bonds, leading to their strong and durable properties.

The Biuret test is specifically used to test for the presence of proteins by detecting the peptide bonds. The other three tests mentioned are used for different types of organic molecules such as starch, reducing sugars, and lipids.

Enzymes are globular proteins that act as catalysts, are specific to substrates, have an active site, and their activity is affected by temperature and pH. The incorrect answers do not accurately describe the features of enzymes, which are essential in biological processes.

The tertiary structure of enzymes is essential for establishing the precise shape of the active site, where the substrate binds and reactions occur. This correct shape is necessary for the enzyme to catalyze reactions efficiently and specifically.

Enzymes are referred to as biological catalysts because they increase the rate of chemical reactions without being consumed in the process.

Enzymes that catalyse reactions outside the cell are known as extracellular enzymes. Intracellular refers to enzymes inside the cell, Endocellular and Pericellular are not commonly used terms in biology.

Proteins are made up of long chains of amino acids, which are the building blocks or monomers of proteins. Nucleotides are the monomers of nucleic acids, fatty acids are building blocks of lipids, and monosaccharides are the monomers of carbohydrates.

An amino acid consists of an amino group, an R group, an Acid group, and a carbon in between which are essential components of its structure.

Plants are capable of synthesizing amino acids through various metabolic pathways, while animals must acquire amino acids from the food they consume.

Amino acids are joined together through a condensation reaction, where a water molecule is removed to form a peptide bond.

Amino acids are split by hydrolysis, which involves breaking down compounds with water.

Primary Structure refers to the linear sequence of amino acids in a protein chain, not the overall shape, breakdown process, or specific function of the protein.

Covalent (disulfide) bonds are the most common in the proteins of organisms that survive in hot environments because they are unaffected by the high temperatures, providing stability to the protein structure.

Enzymes like amylase and lipase are not specifically involved in the breakdown of sugar, while peroxidase is not involved in the breakdown of hydrogen peroxide.