Question

Name an enzyme that acts on each molecule. (a) Amylose (b) Peroxide (c) DNA

Short answer

(a) Amylase, (b) Catalase, (c) DNA polymerase.

Step-by-step solution

Identify the Enzyme for Amylose

Amylose is a polysaccharide that is composed of glucose units linked together in a linear chain. The enzyme that breaks down amylose is called amylase. Amylase hydrolyzes the glycosidic bonds in amylose, breaking it down into simpler sugars such as maltose and glucose.

Identify the Enzyme for Peroxide

Peroxides, such as hydrogen peroxide, are broken down by an enzyme called catalase. Catalase catalyzes the decomposition of hydrogen peroxide into water and oxygen, which is a crucial reaction in protecting cells from oxidative damage caused by peroxide accumulation.

Identify the Enzyme for DNA

DNA, or deoxyribonucleic acid, is acted upon by various enzymes depending on the reaction occurring. One key enzyme that acts on DNA during replication is DNA polymerase. DNA polymerase is responsible for synthesizing new strands of DNA by adding nucleotides complementary to the template strand during replication.

Key concepts

Amylase

Amylase is a vital enzyme primarily involved in breaking down carbohydrates into simpler sugars. This enzyme targets amylose, a polysaccharide component of starch that consists of glucose units connected in a linear chain.
Amylase accomplishes its task by hydrolyzing the glycosidic bonds between glucose molecules. This reaction converts amylose into maltose and eventually into glucose, providing essential energy for cellular functions.

• Found in saliva and the pancreas, amylase initiates starch digestion in the mouth and completes it in the small intestine.
• Two main types of amylase include alpha-amylase, which acts randomly along the starch chain, and beta-amylase, which is more selective, breaking down starch from the non-reducing ends.

Understanding amylase is crucial, especially for those studying nutrition, biology, or health sciences, as it is essential for converting dietary starches into absorbable glucose during digestion.

Catalase

Catalase plays a crucial role in cellular health by breaking down potentially harmful peroxides, such as hydrogen peroxide, into harmless substances like water and oxygen. Hydrogen peroxide is a by-product of various metabolic processes and, if accumulated, can cause oxidative damage to cells.
Catalase's decomposition reaction is vital for protecting cells and tissues from oxidative stress. This enzyme acts with remarkable speed, converting millions of peroxide molecules each second, ensuring swift removal of these toxic by-products.

• Catalase is ubiquitously found in the cells of aerobic organisms, enabling them to tolerate some level of oxidation from cellular respiration.
• Beyond simple breakdown, catalase also offers insight into evolutionary biology, indicating how organisms have adapted to manage oxidative stress.

By studying catalase, students gain a deeper understanding of enzymatic protective mechanisms and the broader implications of enzyme action in living organisms.

DNA polymerase

DNA polymerase is an essential enzyme with a pivotal role in DNA replication and repair. This enzyme synthesizes new strands of DNA by adding nucleotides that are complementary to the template strand. The accuracy of DNA polymerase in matching A's with T's and G's with C's ensures the fidelity of genetic information.
DNA polymerase functions during the S phase of the cell cycle, ensuring each new cell has an accurate copy of genetic material before cell division.

• Key types of DNA polymerases include DNA polymerase I for replacing RNA with DNA nucleotides, DNA polymerase III for the bulk of synthesis, and specialized polymerases involved in repair mechanisms.
• The enzyme requires a primer to initiate synthesis, which is usually a short RNA section synthesized by another enzyme, primase.

Understanding DNA polymerase underscores the intricacy of genetic processes and the maintenance of life, forming a foundation for studies in genetics, molecular biology, and biotechnology.