KE REVIEW ~ UNIT 2

The graph shows how the activity of an enzyme changes at different temperatures. Which statement best describes what happens to the enzyme when the temperature of the reaction increases to 63°C?

• The enzyme is used up and the reaction stops.

• The enzyme begins to decrease the rate of the reaction.

• The enzyme continues to increase the rate of the reaction.

• The enzyme changes shape and can no longer speed up the reaction.

Microbes in the digestive system break down food, which allows nutrients to be absorbed by the body’s cells. How will these body cells most likely be affected if an individual suffers from a high fever?

• The body cells will swell because an increase in temperature promotes greater water absorption.

• The body cells will stop absorbing nutrients because the heat melts the lipid bilayer of the plasma membrane.

• The body cells will shrivel because the heat eliminates the chemical gradients on either side of the plasma membrane.

• The body cells will bring in fewer nutrient molecules because the transport proteins lose their proper shape due to the high temperature.

Tags

NGSS.HS-LS1-3

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

The element carbon has multiple bonding patterns. Which bonding pattern cannot be formed by carbon?

• 
• 
• 
• 

Tags

NGSS.HS-LS1-6

Trees are typically able to transport water from their roots to their stems and leaves. Which statement describes the property of water that most supports the transportation of water to all parts of a tree?

• Water forms a crystalline structure when it freezes.

• Water dissolves fewer substances than any other liquid.

• Water has strong attractions to itself and many other molecules.

• Water can absorb large amounts of energy with minimal temperature changes.

Which statement best compares a carbohydrate and a nucleic acid?

• The sequence of monomers in a carbohydrate stores genetic information, and the bonds in a nucleic acid store energy.

• The bonds in a carbohydrate store energy, and the sequence of nucleotides in a nucleic acid stores genetic information.

• A carbohydrate has a unique structure to assist diffusion across a plasma membrane, and a nucleic acid has a unique structure to assist chemical reactions.

• A carbohydrate has a unique structure to assist chemical reactions, and a nucleic acid has a unique structure to assist diffusion across a plasma membrane.

The enzyme pepsin is found in the stomach. Which medicine is most likely to directly interfere with pepsin’s function?

• a medicine that affects pH

• a medicine that prevents clotting

• a medicine that blocks neural impulses

• a medicine that lowers cholesterol levels

Many plants have a waxy coating on their leaves. Which statement describes the most likely structure and function of the waxy coating?

• The waxy coating is a protein that can help attract other organisms for pollination.

• The waxy coating is a protein that can help release waste molecules during transpiration.

• The waxy coating is a lipid that can help absorb more sunlight in hot environments.

• The waxy coating is a lipid that can help prevent excess water loss in dry environments.

The diagram models how a poison bonds to the active site of an enzyme. Which function is the enzyme most likely unable to perform because of the attachment of the poison molecule?

• the release of stored chemical energy

• the donation of electrons to the substrate

• the supply of activation energy for a reaction

• the catalysis of the reaction with the substrate

Tags

NGSS.HS-PS1-5

Each cell in the human body contains thousands of different enzymes responsible for regulating reactions within the cell. Which statement explains why a single enzyme is unable to regulate a variety of reactions?

• The binding of a product and an enzyme is specific.

• The binding of a substrate and an enzyme is specific.

• The enzyme is consumed by the products of the reactions.

• The enzyme is consumed by the substrates of the reactions.