Unit 1 bio molecules

A person starts to eat a hamburger. As she takes a bite and chews, an enzyme called salivary lipase helps to begin the process of fat digestion. Which of these is the BEST description of the role of enzymes during digestion?

Responses

• Enzymes are acids that physically break down food molecules.

• Enzymes moisten food to help teeth in the mechanical process of grinding and chewing.

• Enzymes are proteins that speed up the process of chemically breaking down food molecules.

• Enzymes are cells that secrete saliva and other necessary substances needed for digestion.

Answer explanation

Enzymes speed up the process of breaking down food chemically using saliva.

Which of these organic molecules functions to help speed up biological chemical reactions?

• nucleic acids

• proteins

• carbohydrates

• lipids

Biomolecules are essential organic molecules which are involved in the maintenance and metabolic processes of living organisms. Biomolecules include carbohydrates, lipids, proteins, and nucleic acids. These vary in composition, structure, and function. Select ALL of the choices that correctly pairs the biomolecule and one of its functions.

• carbohydrates: make up plant cell walls

• nucleic acids: store genetic information

• proteins: store energy

• nucleic acids: chemical messengers (hormones)

• lipids: compose part of the cell membrane

In this lab, biology students were directed to use indicators as chemical detection tools, to analyze a variety of foods for the presence of carbohydrates, lipids or proteins. One group of students was given four unmarked containers of sugars: glucose, sucrose, fructose, and galactose. How could they use the standard lab tests to find the sucrose?

Responses

• They could use the Benedict's test; sucrose would have a positive Benedict's test and the other sugars would not.

• They could use the Biuret test; it would not have a positive reaction for sucrose but it would for the other three sugars.

• They could use the Benedict's test; it would not have a positive reaction for sucrose but it would for the other three sugars.

• They could use the iodine test; because sucrose is not a monosaccharide, it would have a positive iodine test and the others would not.

All the biological macromolecules contain carbon, hydrogen and oxygen. However, most do not contain nitrogen. The category that contains nitrogen are

• proteins

• lipids

• carbohydrates

• unsaturated fats

Biomolecules are the large molecules necessary for life that are built from smaller organic molecules. There are four major classes of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids, and each is an important component of the cell and performs a wide variety of functions. Some common biomolecule functions are listed below. Select ALL the functions of proteins.

• provide immunity

• catalyze reactions

• provide structure

• store genetic information

• first-line energy storage

Proteins are made of ________________________, and the sequence of these determine how the protein will fold up and take shape, which ultimately determines it's function.

• amino acids

• monosaccharides

• nucleotides

• lipids