Molecular Biochemistry

 Proteins have many different functions in a cell. Which of the following are possible functions of a protein?

• catalysts and building blocks of DNA
• enzymes and actively transports molecules across the cell membrane
• building blocks of DNA and structural components of cell membrane
• components of the cell membrane and main source of energy in cellular respiration

Water is essential to all living things. One important attribute of water allows it to maintain a constant environment within cells. Which property of water allows it to do this?

• moderates temperature
• breaking of covalent bonds
• surface tension of water surface
• expansion of water when it freezes

Tags

NGSS.HS-LS1-3

The human body maintains a temperature of around 98.6 degrees at all times. Enzymes are involved in almost every chemical reaction in the body. Which of the following describes the connection between these two statements?

•  Enzymes function best at a specific temperature
• The body needs to be warm to prevent hypothermia.
• The body is kept relatively warm to prevent too much enzyme action
• There is no connection between the two statements.

Tags

NGSS.HS-LS1-3

A sugar, a phosphate group, and a nitrogen base form the building blocks of which organic compound?

• carbohydrates
• lipids
• nucleic acids
• proteins

Water is often called the "universal solvent" because many substances can be dissolved in water. What property of water allows it to be such a versatile solvent?

• purity

• polarity

• high heat capacity

• expansion upon freezing

Tags

NGSS.HS-ESS2-5

Which of the following best compares the structures of lipids and carbohydrates?  

• Both are made up of monosaccharide monomers, but lipids are hydrophobic and carbohydrates are hydrophilic.
• Both contain carbon and hydrogen, but carbohydrates also contain oxygen and lipids contain nitrogen.
• Both consist of carbon, hydrogen, and oxygen, but carbohydrates have repeating structural units and lipids do not.
• Both have a carbon backbone, but lipids also have an amino group and carbohydrates have a carboxylic acid group.

Which row in the chart below correctly pairs a food molecule with its building block?

• Row 1
• Row 2
• Row 3
• Row 4

Tags

NGSS.HS-LS1-6

Which of these biological functions is made more effective by the hydrogen-bonding properties of water?

• lubrication of joints as a means of preventing injury
• sweating as a means of regulating body temperature
• transmitting signals and information as a means of  body movement
• breathing as a means of taking in oxygen and releasing carbon dioxide

A scientist analyzing an unknown substance has determined that it consists only of carbon, hydrogen and oxygen. During experimentation, she determines that the substance is soluble, or dissolves, in OIL but not in water. Which of the following macromolecules is the unknown substance most likely to be?

•  carbohydrate
• lipid
• nucleic acid
• protein

Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enables it to move from the roots to the leaves of plants?

• Water expands as it freezes.

• Water is an excellent solvent.

• Water exhibits cohesive and adhesive behavior.

• Water is able to moderate temperature.