Organic Molecules Study Island

The above graph shows how temperature affects the rate of a reaction that uses the catalase enzyme. At what temperatures, approximately, is the enzyme denatured?

60 and 100

All cells in multicellular organisms contain thousands of different kinds of enzymes that are specialized to catalyze different chemical reactions. Given this information, which of the following is most likely to be true?

All cells do not contain the same types of enzymes.

The above graph shows how temperature affects the rate of a reaction that uses the catalase enzyme. What trend is shown by the graph?

Between zero and twenty-seven degrees Celsius, the rate of the reaction increases as the temperature increases.

Which of the following best describes a carbohydrate?

Carbohydrates are organic macromolecules that are made up of carbon, hydrogen, and oxygen atoms and are used for energy storage or as structural molecules.

In order for cells to function properly, the enzymes that they contain must also function properly. What can be inferred using the above information?

Cells do not function well at pH's that are too high or too low.

Catalase is an enzyme that is found in all living tissues. Cells need catalase in order to function properly. Which of the following statements can be inferred using the above information?

Cells only function within a specific temperature range because enzymes only function within a specific temperature range.

Carbohydrates, such as glucose, are excellent sources of immediate energy for living organisms. More complex carbohydrates, such as glycogen and starch, can also be used for the long term storage of energy. However, carbohydrates play other vital roles, too. Which of the following describes another common use for carbohydrates?

Cellulose is used as a structural component in plant cell walls.

Which of the following are examples of nucleic acids?

DNA and RNA

Which of the following conclusions can be drawn from this graph?

Each enzyme operates best within a certain pH range.

What molecule is catalase breaking down in this reaction?

H2O2

An enzyme is a biomolecule that increases the rate of a chemical reaction. Which of the following is true about enzymes?

I and II only

Which of the following is true about nucleic acids?

I and II only

If the black line represents a reaction without an enzyme and the red line represents the same reaction with the addition of an enzyme, what can be said of the relationship between the use of an enzyme and the energy of the reaction?

More energy is absorbed by reactions without an enzyme.

A cell's work is carried out by the many different types of molecules it assembles. _________ are especially important because they are involved in a variety of processes, such as cell signaling, immune response, and enzyme activity.

Proteins

A reaction that is catalyzed by an enzyme usually absorbs less energy and is faster than normal reactions. Which of the reactions was most likely catalyzed by an enzyme?

Reaction B

When cellular respiration occurs within a cell, carbon dioxide is formed as a waste product. The carbon dioxide is transported out of the cell and absorbed by the blood stream. There, the carbon dioxide undergoes a chemical reaction and forms carbonic acid within the blood. When the carbonic acid reaches the capillaries in the lungs, the enzyme carbonic anhydrase helps reverse the reaction, and the carbonic acid is converted back to carbon dioxide and water. Which of the following would most likely happen if a person's body stopped producing carbonic anhydrase?

The blood's acidity would increase and become toxic.

How does the structure of this enzyme help with its function?

The enzyme's shape fits its substrate's shape, thus allowing the enzyme to catalyze the appropriate reaction.

Pepsin is produced by cells lining the stomach. It catalyzes reactions needed to digest certain proteins. After leaving the stomach, food enters the small intestine. The pH of the small intestine is around 7. What would most likely happen to pepsin enzymes that traveled with the food from the stomach to the small intestines?

The pepsin would become inactive.

Lactase is an enzyme that breaks down the complex carbohydrate lactose into glucose and galactose, which can be absorbed by the bloodstream and carried to the body's cells. Lactose is found primarily in dairy products. What would most likely happen to a person who had a shortage of lactase?

The person would be unable to fully digest dairy products

A biochemist is attempting to replicate a chemical reaction that commonly takes place in cells. During the chemical reaction, starch is broken down into glucose. What will most likely happen if the biochemist adds an enzyme to the reactants?

The reaction will speed up.

Which of the following is true about protein molecules?

The shape and folded structure of a protein molecule are important in determining its function.

Pepsin is found in the stomach. Salivary amylase is found in the mouth. And arginase is found in the liver. What does the graph indicate about the relative acidity of these three locations?

The stomach is more acidic than the mouth, which is more acidic than the liver.

What can Tobin conclude about the relationship between the enzyme concentration and the reaction rate in the presence of excess molecules?

There is a direct relationship; as the enzyme concentration increases, the rate of reaction increases.

Enzymes are catalysts. This means that they are able to speed up chemical reactions. Which of the following statements is also true of enzyme catalysts?

They are not used up by reactions.

How does the structure of amylose compare to the structure of glycogen?

They contain the same monomer subunits but they are arranged differently.

Many of the biochemical reactions that occur within your cells are catalyzed by enzymes. Which of the following statements is true about most enzyme-assisted reactions?

They occur more quickly than reactions without enzymes.

Homeostasis is the ability of an organism to maintain a relatively stable internal environment. How would an organism's homeostasis be affected if it was not able to produce enzymes?

Without enzymes, chemical reactions would not occur quickly enough to sustain life.

The picture above shows two monomer units of a nucleic acid chain. What are the components that make up each nucleotide monomer?

a five-carbon sugar, a phosphate group, and a nitrogenous base

A large carbohydrate molecule is composed of several subunits, such as glucose. An example of a large carbohydrate molecule is _______.

all of these

Enzymes are a type of protein that aid in which of the following processes?

all of these

In most animal cells, a complex network of proteins provides which of the following?

all of these

In which of the following are lipids found?

all of these

Cellular processes are carried out by many different types of molecules, mostly proteins. The function of each protein molecule depends on its shape which, in turn, is determined by the protein's specific sequence of _______.

amino acids

Protein molecules are composed of long chains of

amino acids

Proteins are used for many structural functions such as in the actin and myosin in muscle or as a part of the cytoskeleton scaffolding that maintains cell shape. What other main function do proteins serve?

as enzymes to control the rate of reactions and regulate cellular activity

The above graph shows how temperature affects the rate of a reaction that uses the catalase enzyme. At what temperatures, approximately, is the enzyme the most effective?

between 27°C and 37°C

Sugars are a type of _______. They are produced by plants and release energy when they are broken down into smaller molecules.

carbohydrate

Sugars such as glucose, fructose, and ribose are examples of _______.

carbohydrates

Carbohydrates are composed of which three elements?

carbon, hydrogen, and oxygen

There are twenty standard amino acids that make up all proteins. What four elements are found in all amino acids?

carbon, hydrogen, oxygen, and nitrogen

n enzyme is a biomolecule that increases the rate of a chemical reaction. An enzyme is a kind of

catalyst

Greg performed an experiment in which he measured the reaction rate of two different enzymes at varying pH's. His results appear in the table below:

enzymes have particular pH's at which they function best.

A student is given a small amount of unknown tan-colored liquid substance. This unknown liquid is placed into a glass of water and mixed. Despite mixing, the tan liquid remains separated from the water and collects as a large droplet at the top. Which of the macromolecule groups is this liquid MOST likely to be a member of?

lipids

Organic macromolecules called _______ are insoluble in water, are often found in biological membranes and other waterproof coverings, and have the ability to store energy for extended periods of time.

lipids

What molecules can produce more energy per gram than sugars and are used for storing energy in animals?

lipids

To which of the following could this complex best be compared?

lock and key

The characteristics of all organisms and viruses are determined by the instructions carried in _______.

nucleic acids

Suppose that enzyme X catalyzes a reaction that involves the breakdown of a molecule. The product of this reaction is an amino acid. What molecule is the enzyme breaking down?

protein

_______ are made from chains of amino acids. They are the building blocks of tissues, such as skin and muscles.

proteins

are especially important because they are involved in a variety of processes, such as cell signaling, immune response, and enzyme activity.

proteins

Each enzyme produced by the body is

specific—meaning it is only able to catalyze a reaction with a certain molecule.

Polymers of the carbohydrate monomer glucose are used as the major form of energy storage for many plants. What are these glucose polymers called?

starch

The darker parts occur on the cooler parts of the cat's body because the enzyme that catalyzes the formation of the dark pigment is more active when cool. This example shows that enzymes are affected by .

temperature

Any factor that changes the shape of an enzyme can affect the enzyme's activity. Which of the following two factors affect an enzyme's operation the most?

temperature and pH

Nucleic acids, proteins, and other large biological molecules are known as polymers because

they contain many small, repeating subunits bonded together.