UNIT 2 REMEDIATION (2022-23)

Which of the following is a property of water that allows a water strider to walk on the surface of water?

• solubility

• surface tension

• high specific heat

• low freezing point

Cells are largely made of organic compounds that contain carbon. 

Which property of the carbon atom makes it an essential component of organic compounds?

• Carbon is a nonmetal.

• Carbon oxidizes to carbon dioxide.

• Carbon is solid at room temperature.

• Carbon can form four covalent bonds.

Use the chart to answer the question.

Which biological molecules are most likely represented by molecules 1 and 2?

• molecule 1: lipid molecule 2: nucleic acid

• molecule 1: lipid molecule 2: protein

• molecule 1: carbohydrate molecule 2: nucleic acid

• molecule 1: carbohydrate molecule 2: protein

Lipase is an enzyme that breaks down lipids in the digestive system of humans . It functions best at a pH range of 4 .0 to 5 .0 . When a person takes an antacid tablet to relieve heartburn, the antacid increases the pH to around 7 in certain areas of the digestive system . Which initial effect would most likely be caused by a change in pH?

• More lipids would be digested.

• Fewer lipids would be digested.

• The production of lipase molecules would increase.

• The production of lipase molecules would decrease.

__________ = "water-loving"

• hydrolase

• hydrolysis

• hydrophilic

• hydrophobic

Which statement best describes how amino acids become polymers?

• Water is added as amino acids link to form proteins.

• Water is released as amino acids break apart to form proteins.

• Peptide bonds link amino acids together as proteins form.

• Peptide bonds break between amino acids as proteins form.

Which stores the most energy?

• carbohydrates

• lipids

• proteins

• nucleic acids

Substance A is converted to substance B in a metabolic reaction. 

Which statement best describes the role of an enzyme during this reaction?

• It adjusts the pH of the reaction medium.

• It provides energy to carry out the reaction.

• It dissolves substance A in the reaction medium.

•  It speeds up the reaction without being consumed.

Which statement best describes an effect of the low density of frozen water in a lake?

• When water freezes, it contracts, decreasing the water level in a lake.

• Water in a lake freezes from the bottom up, killing most aquatic organisms.

• When water in a lake freezes, it floats, providing insulation for organisms below.

• Water removes thermal energy from the land around a lake, causing the lake to freeze.

How does having four valence electrons make carbon an ideal element to form biological macromolecules?

•   It allows carbon to form four covalent bonds.

•   It allows carbon to exist in four different states.

• It allows carbon to form four different compounds.

• It allows carbon to have four different carbon-based structures.