Organic Molecules

The graph below shows changes in the concentrations of glucose and insulin in the blood of a human over a period of time. Which statement correctly explains these changes? (1) High glucose levels cause more insulin to be released. (2) High insulin levels cause more glucose to be released. (3) Low glucose levels cause more insulin to be released. (4) Low insulin levels cause more glucose to be released.

(1) High glucose levels cause more insulin to be released.

A student performed an experiment to demonstrate that a plant needs chlorophyll for photosynthesis. He used plants that had green leaves with white areas. After exposing the plants to sunlight, he removed a leaf from each plant and processed the leaves to remove the chlorophyll. He then tested each leaf for the presence of starch. Starch was found in the area of the leaf that was green, and no starch was found in the area of the leaf that was white. He concluded that chlorophyll is necessary for photosynthesis. Which statement represents an assumption the student had to make in order to draw this conclusion? (1) Starch is synthesized from the glucose produced in the green areas of the leaf. (2) Starch is converted to chlorophyll in the green areas of the leaf. (3) The white areas of the leaf do not have cells. (4) The green areas of the leaf are heterotrophic.

(1) Starch is synthesized from the glucose produced in the green areas of the leaf.

Which condition is necessary for enzymes and hormones to function properly in the human body? (1) These chemicals must have a specific shape. (2) These chemicals must be able to replicate. (3) Body temperature must be above 40°C. (4) Body pH must be above 10.

(1) These chemicals must have a specific shape.

An increase in the level of insulin in the blood would most directly result in (1) a decrease in the amount of glucose in the blood (2) a decrease in the amount of protein in the blood (3) an increase in the amount of fat in cells (4) an increase in the amount of carbon dioxide in cells

(1) a decrease in the amount of glucose in the blood

Experiments revealed the following information about a certain molecule:- It can be broken down into amino acids.- It can break down proteins into amino acids.- It is found in high concentrations in the small intestine of humans. This molecule is most likely (1) an enzyme (2) an inorganic compound (3) a hormone (4) an antigen

(1) an enzyme

The diagram below represents a series of reactions that can occur in an organism. This diagram best illustrates the relationship between (1) enzymes and synthesis (2) amino acids and glucose (3) antigens and immunity (4) ribosomes and sugars

(1) enzymes and synthesis

The failure to regulate the pH of the blood can affect the activity of (1) enzymes that clot blood (2) red blood cells that make antibodies (3) chlorophyll that carries oxygen in the blood (4) DNA that controls starch digestion in the blood

(1) enzymes that clot blood

In plants, simple sugars are least likely to be (1) linked together to form proteins (2) broken down into carbon dioxide and water (3) used as a source of energy (4) stored in the form of starch molecules

(1) linked together to form proteins

Fat molecules typically contain long chains of carbon atoms. Animals tend to store fats for use when food resources are scarce. This is an advantage to the animal because (1) much energy can be gained by breaking the bonds between atoms in the fats (2) fats give off carbon dioxide that can be used by the muscles (3) amino acids from fat synthesis are more easily digested than carbohydrates (4) energy can only be created by digesting fats

(1) much energy can be gained by breaking the bonds between atoms in the fats

A characteristic shared by all enzymes, hormones, and antibodies is that their function is determined by the (1) shape of their molecules (2) DNA they contain (3) inorganic molecules they contain (4) Organelles present in their structure

(1) shape of their molecules

The enzyme amylase will affect the breakdown of carbohydrates, but it will not affect the break- down of proteins. The ability of an enzyme molecule to interact with specific molecules is most directly determined by the (1) shapes of the molecules involved (2) number of molecules involved (3) sequence of bases present in ATP (4) amount of glucose present in the cell

(1) shapes of the molecules involved

Substances X and Y are examples of which kind of molecule? (1) simple sugar (3) fat (2) amino acid (4) hormone

(1) simple sugar

The sequence of subunits in a protein is most directly dependent on the (1) region in the cell where enzymes are produced (2) DNA in the chromosomes in a cell (3) type of cell in which starch is found (4) kinds of materials in the cell membrane

(2) DNA in the chromosomes in a cell

Which characteristic allows enzymes to function in a specific way? (1) Enzymes are complex compounds composed of starch. (2) Each enzyme has a characteristic shape. (3) Enzymes are long, complex fats. (4) Each enzyme is made up of four subunits.

(2) Each enzyme has a characteristic shape.

Meat tenderizer contains an enzyme that interacts with meat. If meat is coated with tenderizer and then placed in a refrigerator for a short time, how would the enzyme be affected? (1) It would be broken down.(2) Its activity would slow down. (3) Its shape would change.(4) It would no longer act as an enzyme.

(2) Its activity would slow down.

The graph below represents data obtained from an experiment on starch digestion. Which statement best describes point A and point B on the graph? (1) The concentration of sugars is greater at point A than it is at point B. (2) The concentration of sugars is greater at point B than it is at point A. (3) The starch concentration is the same at point A as it is at point B. (4) The starch concentration is greater at point B than it is at point A.

(2) The concentration of sugars is greater at point B than it is at point A.

A process that occurs in the human body is shown in the diagram below. What would happen if a temperature change caused the shape of the active site to be altered? (1) The dipeptide would digest faster. (2) The dipeptide would digest slower or not at all. (3) The amino acids would combine faster. (4) The amino acids would combine slower or not at all.

(2) The dipeptide would digest slower or not at all.

Which statement best describes enzymes? (1) Every enzyme controls many different reactions. (2) The rate of activity of an enzyme might change as pH changes. (3) Temperature changes do not affect enzymes. (4) Enzymes are produced from the building blocks of carbohydrates.

(2) The rate of activity of an enzyme might change as pH changes.

Starch turns blue black in the presence of a starch indicator. Dialysis tubing tied at both ends and containing starch solution is placed in a beaker of water. Yellowish brown starch indicator is then added to the water. What will the solutions in the beaker and the tubing look like after 20 minutes? (1) The indicator solution in the beaker will be blue black and the starch solution in the tubing will not change color. (2) The starch solution in the tubing will be blue black and the indicator solution in the beaker will not change color. (3) Neither the indicator solution nor the starch solution will be blue black. (4) Both the indicator solution and the starch solution will be blue black.

(2) The starch solution in the tubing will be blue black and the indicator solution in the beaker will not change color.

Which statement describes starches, fats, proteins, and DNA? (1) They are used to store genetic information. (2) They are complex molecules made from smaller molecules. (3) They are used to assemble larger inorganic materials. (4) They are simple molecules used as energy sources.

(2) They are complex molecules made from smaller molecules.

The diagram below illustrates a biochemical process that occurs in organisms. The substance labeled â catalyst" is also known as (1) a hormone (2) an enzyme (3) an antibody (4) an inorganic compound

(2) an enzyme

The shape of a protein is most directly determined by the (1) amount of energy available for synthesis of the protein (2) kind and sequence of amino acids in the protein (3) type and number of DNA molecules in a cell (4) mistakes made when the DNA is copied

(2) kind and sequence of amino acids in the protein

Three days after an organism eats some meat, many of the organic molecules originally contained in the meat would be found in newly formed molecules of (1) glucose (3) starch (2) protein (4) oxygen

(2) protein

Which group consists entirely of organic molecules? (1) protein, oxygen, fat (2) protein, starch, fat (3) water, carbon dioxide, oxygen (4) water, starch, protein

(2) protein, starch, fat

Most of the starch stored in the cells of a potato is composed of molecules that originally entered these cells as (1) enzymes (2) simple sugars (3) amino acids (4) minerals

(2) simple sugars

The equation below represents a chemical reaction that occurs in humans. What data should be collected to support the hypothesis that enzyme C works best in an environment that is slightly basic? (1) the amino acid sequence of enzyme C (2) the amount of substance W produced in five minutes at various pH levels (3) the shapes of substances X and Y after the reaction occurs (4) the temperature before the reaction occurs

(2) the amount of substance W produced in five minutes at various pH levels

The diagrams below represent two molecules that are involved in metabolic activities in some living cells. The shape of each of the molecules is important because (1) molecules having different shapes are always found in different organisms (2) the shape of a molecule determines how it functions in chemical reactions (3) the shape of a molecule determines the age of an organism (4) if the shape of any molecule in an organism changes, the DNA in that organism will also change

(2) the shape of a molecule determines how it functions in chemical reactions

The graph below represents the effect of pH on three different enzymes at normal body temperature. The graph illustrates that enzymes 1, 2, and 3 (1) are not affected by pH (3) work best in an acidic environment (2) work best at different pH levels (4) work best in a basic environment

(2) work best at different pH levels

The diagram below represents a biological process. Which set of molecules is best represented by letters A and B? (1) A: oxygen and water B: glucose (2) A: glucose B: carbon dioxide and water (3) A: carbon dioxide and water B: glucose (4) A: glucose B: oxygen and water

(3) A: carbon dioxide and water B: glucose

The two diagrams below represent a sugar molecule and a fat molecule that are used by living organisms. Which statement best describes these two molecules? (1) Sugar molecules are inorganic and fat molecules are organic. (2) Sugar molecules are organic and fat molecules are inorganic. (3) Energy for life processes can be stored within the chemical bonds of both molecules. (4) Energy for life processes can be stored within the chemical bonds of sugar molecules, only.

(3) Energy for life processes can be stored within the chemical bonds of both molecules.

Certain organisms are able to store energy from the Sun in energy-rich compounds. Which event best illustrates this activity? (1) A fox captures and eats a young rabbit. (2) A caterpillar is eaten by a blackbird. (3) Lettuce produces organic substances. (4) Bacteria change organic material into simple nutrients.

(3) Lettuce produces organic substances.

Lysosomes break open during the process of digestion, releasing enzymes into the cytoplasm. Which statement may explain why the entire cell may not be digested? (1) The acidic environment of the cytoplasm destroys the enzymes. (2) Antibodies in the cytoplasm break down foreign enzymes. (3) The pH of the cytoplasm causes the enzymes to function less effectively. (4) Enzymes can function only in the location where they are synthesized.

(3) The pH of the cytoplasm causes the enzymes to function less effectively.

Which statement describes all enzymes? (1) They control the transport of materials. (2) They provide energy for chemical reactions. (3) They affect the rate of chemical reactions. (4) They absorb oxygen from the environment.

(3) They affect the rate of chemical reactions.

Which statement concerning simple sugars and amino acids is correct'?(1) They are both wastes resulting from protein synthesis. (2) They are both building blocks of starch. (3) They are both needed for the synthesis of larger molecules. (4) They are both stored as fat molecules in the liver.

(3) They are both needed for the synthesis of larger molecules.

Synthesis of a detective protein may result from an alteration in (1) vacuole shape (2) the number of mitochondria (3) a base sequence code (4) cellular fat concentration

(3) a base sequence code

The inability of an organism to produce certain proteins can occur when an organism is lacking an enzyme needed to combine (1) oxygen molecules (3) amino acids (2) simple sugars (4) biological catalysts

(3) amino acids

A scientist plans to cut a segment of DNA so that it can be inserted into the DNA of a bacterium, a single-celled organism. The scientist needs to use a special type of organic molecule to perform this cutting process. This molecule is (1) a lipid (3) an enzyme (2) a carbohydrate (4) a hormone

(3) an enzyme

Luciferin is a molecule that, when broken down in fireflies, produces heat and light. The rate at which luciferin is broken down in cells is controlled by (1) a carbohydrate (2) a simple sugar (3) an enzyme (4) a complex fat

(3) an enzyme

Plants such as the Venus flytrap produce chemical compounds that break down insects into substances that are usable by the plant. The chemical compounds that break down the insects are most likely (1) fats (2) minerals (3) biological catalysts (4) complex carbohydrates

(3) biological catalysts

More energy can be released from a fat molecule than from a glucose molecule because the fat molecule contains more (1) genes (3) chemical bonds (2) organic compounds (4) mitochondria

(3) chemical bonds

Many biological catalysts, hormones, and receptor molecules are similar in that, in order to function properly, they must (1) interact with each other at a high pH (2) interact with molecules that can alter their specific bonding patterns (3) contain amino acid chains that fold into a specific shape (4) contain identical DNA base sequences

(3) contain amino acid chains that fold into a specific shape

Before starch can enter a cell, it must be (1) absorbed by simple sugars (2) diffused into simple sugars (3) digested to form simple sugars (4) actively transported by simple sugars

(3) digested to form simple sugars

Organisms contain compounds such as proteins, starches, and fats. The chemical bonds in these compounds can be a source of (1) amino acids (3) energy (2) simple sugars (4) enzymes

(3) energy

The chemicals present in the plants that break down the insects are most likely (1) fats (3) enzymes (2) hormones (4) carbohydrates

(3) enzymes

Enzyme molecules normally interact with substrate molecules. Some medicines work by blocking enzyme activity in pathogens. These medicines are effective because they (1) are the same size as the enzyme (2) are the same size as the substrate molecules (3) have a shape that fits into the enzyme (4) have a shape that fits into all cell receptors

(3) have a shape that fits into the enzyme

If the temperature of the tissue samples used in the experiment had been raised from 37°C (body temperature) to 50°C, the results would have been different because (1) more enzymes are produced at higher temperatures, increasing the amount of hydrogen peroxide (2) more hydrogen peroxide is released at higher temperatures, increasing the activity of catalase (3) increasing temperatures altered the structure of catalase, decreasing oxygen production (4) increasing temperatures decreased the synthesis of amino acids, increasing levels of hydrogen peroxide

(3) increasing temperatures altered the structure of catalase, decreasing oxygen production

Eating a sweet potato provides energy for human metabolic processes. The original source of this energy is the energy (1) in protein molecules stored within the potato (2) from starch molecules absorbed by the potato plant (3) made available by photosynthesis (4) in vitamins and minerals found in the soil

(3) made available by photosynthesis

When organisms break the bonds of organic compounds, the organisms can (1) use the smaller molecules to plug the gaps in the cell membrane to slow diffusion (2) use the energy obtained to digest molecules produced by respiration that uses oxygen (3) obtain energy or reassemble the resulting materials to form different compounds (4) excrete smaller amounts of solid waste materials during vigorous exercise

(3) obtain energy or reassemble the resulting materials to form different compounds

When the substrate concentration increases from 0.4% to 0.5%, the rate of the reaction (1) decreases (2) increases (3) remains the same (4) increases, then decreases

(3) remains the same

A sample of food containing one type of a large molecule was treated with a specific digestive enzyme. Nutrient tests performed on the resulting products showed the presence of simple sugars, only. Based on these test results, the original large molecules contained in the sample were molecules of (1) protein (2) glucose (3) starch (4) DNA

(3) starch

Which substance is an inorganic molecule? (1) starch (3) water (2) DNA (4) fat

(3) water

Which statement explains the importance of maintaining a constant internal environment to ensure proper enzyme functioning? (1) Changes in pH and temperature will cause the enzyme reaction rate to be too fast. (2) Temperature and pH determine amino acid sequences in enzymes. (3) Changes in pH will change the genetic instructions of enzymes. (4) Increasing the temperature and pH can alter the specific shape of enzymes.

(4) Increasing the temperature and pH can alter the specific shape of enzymes.

What will most likely happen to the action of an enzyme from the small intestine if it is placed in an environment similar to the environment in which enzyme C functions best? (1) It would no longer be able to function because the environment is too acidic. (2) It would adapt to the new environment and start carrying out the same function as enzyme C. (3) It would continue to function because it is able to modify the pH of the environment. (4) It would be able to function because the pH of the environment is similar to that of the intestine.

(4) It would be able to function because the pH of the environment is similar to that of the intestine.

Which statement best describes the starch content of two leaves taken from the same plant shown in the chart below? (1) Neither leaf contains starch. (2) Both leaves contain the same amount of starch. (3) Leaf A contains more starch than leaf B. (4) Leaf B contains more starch than leaf A.

(4) Leaf B contains more starch than leaf A.

Molecules A and B come in contact with the cell membrane of the same cell. Molecule A passes through the membrane readily, but molecule B does not. Which statement could describe molecules A and B ? (1) Molecule A is a protein, and molecule B is a fat. (2) Molecule A is a starch, and molecule B is a simple sugar. (3) Molecule A is an amino acid, and molecule B is a simple sugar. (4) Molecule A is a simple sugar, and molecule B is a starch.

(4) Molecule A is a simple sugar, and molecule B is a starch.

The graph below illustrates the relative amounts of product formed by the action of an enzyme in a solution with a pH of 6 at seven different temperatures. Which statement best expresses the amount of product that will be formed at each temperature if the experiment is repeated at a pH of 4? (1) The amount of product formed will be equal to that produced at pH 6. (2) The amount of product formed will be greater than that produced at pH 6. (3) The amount of product formed will be less than that produced at pH 6. (4) The amount of product formed can not be accurately predicted.

(4) The amount of product formed can not be accurately predicted.

Which molecules are needed to cut and copy segments of DNA? (1) reproductive hormones (2) carbohydrates (3) antibodies (4) biological catalysts

(4) biological catalysts

Two proteins in the same cell perform different functions. This is because the two proteins are composed of (1) chains folded the same way and the same sequence of simple sugars (2) chains folded the same way and the same sequence of amino acids (3) chains folded differently and a different sequence of simple sugars (4) chains folded differently and a different sequence of amino acids

(4) chains folded differently and a different sequence of amino acids

An iodine test of a tomato plant leaf revealed that starch was present at 5:00 p.m. on a sunny afternoon in July. When a similar leaf from the same tomato plant was tested with iodine at 6:00 a.m. the next morning, the test indicated that less starch was present. This reduction in starch content most likely occurred because starch was (1) changed directly into proteins (2) transported out of the leaves through the guard cells (3) transported downward toward the roots through tubes (4) changed into simple sugars

(4) changed into simple sugars

An energy-rich organic compound needed by organisms is (1) water (3) oxygen (2) salt (4) glucose

(4) glucose

Which molecule can diffuse from the digestive tract into the human bloodstream without first being digested? (1) protein (3) fat (2) starch (4) glucose

(4) glucose

Starch molecules present in a maple tree are made from materials that originally entered the tree from the external environment as (1) enzymes (2) simple sugars (3) amino acids (4) inorganic compounds

(4) inorganic compounds

Chemicals that help chemical reactions occur at faster rates in living organisms are known as (1) biotic resources (2) simple sugars (3) oxygen molecules (4) organic catalysts

(4) organic catalysts

For which organic compounds must information be encoded in DNA for green plants to synthesize the other three compounds? (1) sugars (2) starches (3) fats (4) proteins

(4) proteins

Which organic compounds would be the best to analyze in order to determine if two species are closely related? (1) fats (3) sugars (2) starches (4) proteins

(4) proteins

What occurs during the digestion of proteins? (l) Specific enzymes break down proteins into amino acids. (2) Specific hormones break down proteins into simple sugars. (3) Specific hormones break down proteins into complex starches. (4) Specific enzymes break down proteins into simple sugars.

(l) Specific enzymes break down proteins into amino acids.