Semester 1 Exam Practice - Pt. 1

Water has the ability to store heat longer than other substances and moderate temperature. This property allows water in cells to absorb much heat without changing. What benefit does this property of water provide to organisms?

• It provides the ability to dissolve nonpolar compounds.

• It enables organisms to function with a higher cellular pH.

• It provides the appropriate catalyst for chemical reactions.

• It allows organisms to maintain a stable internal temperature or homeostasis.

There are four types of biological molecules. The structure below is one of the four biological molecules. Identify the structure below and match it to its function.

• Lipids; insulates the body

• Protein; lowers the activation energy

• Nucleic Acid; stores genetic information

• Carbohydrate; provides short-term energy

What is the relationship between nucleic acids and proteins?

• Proteins and nucleic acids are not related.

• Proteins and nucleic acids are used to create ATP for the cell.

• Proteins are made from the instructions contained in nucleic acids.

• Proteins are long chains of amino acids that combine to form nucleic acids.

The diagram below shows the structure of glucose, a molecule that organisms make and use. Which of the following is not a function of the polymer of this molecule?

• Starch - energy storage in plants

• Glycogen - energy storage in animals

• Cellulose - provides structural support in plants

• Cholesterol - structural component of animal cells

Use the diagram below to answer the following question. Many of the proteins in the human body are enzymes that catalyze chemical reactions. Which reaction has a catalyst/enzyme and what is its effect on the activation energy?

• Reaction 1 has an enzyme; it decreases the activation energy of the product and speeds it up.

• Reaction 1 has an enzyme; it increases the activation energy of the reaction and speeds it up.

• Reaction 2 has an enzyme; it decreases the activation energy of the reaction and speeds it up.

• Both Reaction 1 and Reaction 2 have an enzyme; there is no effect on the activation energy.

Analyze the graph below. What does the graph indicate about enzymes?

• A pH close to 7 is optimal for both enzymes

• Each enzyme functions best within a limited pH range.

• The pH of a solution has little effect on the activity of an enzyme.

• The activity of an enzyme increases as the pH of a solution increases.

Cell theory was first proposed in 1838. Evidence obtained through additional scientific investigations resulted in the current cell theory. Which statement describes a component of the original cell theory that was removed because of the new scientific knowledge?

• All living things are made of cells.

• All cells come from other preexisting cells.

• Cells form through spontaneous generation.

• Cells are the basic structural and functional units of life.

Cell theory is a result of the contributions of several different scientists and applies to all living things. Which of the following explains why cell theory will not ever become the law of cells?

• Cells of different organisms are so diverse that it is impossible to come up with a law that would apply to all of them.

• Because cells undergo change as mutations occur within them, developing anything beyond a cell theory would be impractical.

• Scientific theories are well-tested explanations, while laws are well-tested descriptions of natural phenomena; one cannot become the other.

• Scientific theories can only become laws if all possible cases can be tested; it would be impossible to test all living things to see if they have cell.

Which structures are found in all prokaryotic and eukaryotic cells?

• DNA, ribosomes, and cell wall

• plasma/cell membrane, nucleus, and DNA

• plasma/cell membrane, cytoplasm, and nucleus

• plasma/cell membrane, cytoplasm, and ribosomes

Use the information and the diagram below to answer the following question. Animal cells contain an organelle that helps release energy. A diagram of this organelle is shown below. Which function would the energy-releasing organelle most likely have in the animal cell?

• Cellular control

• Cellular respiration

• Storage of nutrients

• Removal of waste