Unit Two Biology Test

Which of the following is the most diverse group of macromolecules in both function and chemical structure? A. Proteins B. Lipids C. Carbohydrates D. Nucleic acids

A - Based on the slide presentation used in class, it showed that proteins have twenty different monomers and eight different functions that can occur in the human body.

During an experiment Matteo is instructed to add a substance to one setup. This setup goes through the same chemical reaction, but it occurs quicker than the other setups. What do you call the substance Matteo added that caused the reaction to speed up? A. Catalyst B. Solute C. Solvent D. Substrate

A - Because Matteo added a reaction that speeds up, and a catalyst is known for increasing the rate of a chemical reaction without itself undergoing any permanent chemical change.

The picture below shows the nutritional label for Greek yogurt, a milk-based food product that is high in protein. What will happen when the 14 grams of protein in the Greek yogurt is eaten by a person? A. The proteins will be broken down into amino acids. B. The proteins will be combined into monosaccharides. C. The proteins will be combined into polysaccharides. D. The proteins will be broken down into nucleic acids.

A - Because amino acids make up protein.

The diagram below shows the structure of a certain biological macromolecule. Carbon bonds are not drawn to scale. Which macromolecule is shown in the diagram? A. Lipid B. Protein C. Nucleic acid D. Carbohydrate

A - Because it's the only macromolecule that has six common elements in things.

Both lipids and carbohydrates can be used by the cell as... A. energy and storage. B. replacements for salts. C. building blocks for RNA. D. catalysts for metabolic reactions.

A - Because lipids and carbohydrates function as energy-storage molecules and chemical messengers.

A digestive enzyme released into the small intestines by the pancreas is used to break down proteins. Data from a chemical reaction with the digestive enzyme are shown in the graph below. What conclusion can be developed based on the graph? A. The enzyme functions most efficiently from pH 7.0 to pH 9.0. B. The enzyme will work best if pH levels increase above pH 10.0. C. The enzyme breaks down the most proteins between pH 1.0 and pH 5.0. D. The enzyme is effective at breaking down proteins from pH 1.0 to pH 10.0.

A - Because the relative reactivity is higher at pH 7.0 to 9.0, meaning it does its job better.

An investigation was performed with honeybees to determine the average amount of nectar a bee carried in relation to the distance the flowers were from the hive. The following data was collected: State an inference best supported by the data collected.

Amount of nectar carried is not affected by distance.

Jerry conducted an experiment to determine whether salt added to a cup of water affects its freezing point. Water samples were prepared containing equal quantities of water at the same temperature. Each sample received a different amount of salt and was placed into a freezer. The length of time it took for each sample to freeze was recorded as shown below. Identify the effect salt has on the specific heat capacity of water.

An increase in the amount of salt increased the time needed to freeze the samples.

Which of the following correctly completes the table? A. A = DNA or RNA, B = cell fuel and support, C = galactose and glycogen, D = nucleic acids and fatty acids B. A = DNA or RNA, B = cell fuel and support, C = fatty acids and glycerol , D = hemoglobin and actin C. A = fructose and lipids, B = cell control and fuel, C = enzyme and catalyst, D = nucleotides and myosin D. A = hemoglobin and insulin, B = cell control and reproduction, C = deoxyribose and ribose, D = sugars and lipids

B - Because DNA/RNA contain sugar phosphate and nitrogen base, and a steroid (the example in C) is a lipid, making it have monomers of fatty acids and glycerol.

Sophia produces the graph shown below during a biology class investigation. What could she infer about the probable difference between the original reaction and Reaction B based on the data? A. Glucose was added to Reaction B. B. A catalyst was added to Reaction B. C. Additional water was added to Reaction B. D. Additional reactants were added to Reaction B.

B - Because a catalyst is something that can lower the rate of the reaction without entering the reaction itself.

An advertisement for a health supplement for dogs claims to build lean muscle and strengthen tendons and ligaments, as well as provide energy. Which two biomolecules must the supplement contain to provide these benefits? A. Carbohydrates and lipids B. Proteins and carbohydrates C. Nucleic acids and carbohydrates D. Lipids and nucleic acids

B - Because carbohydrates provide energy, while proteins are known to help build muscle and strengthen tendons and ligaments.

Stalks of celery are placed into beakers of colored water. After a few minutes, the colored water has moved up into the celery stalk's tubes. What statement below best describes this result? A. Roots sucked up the colored water. B. The water molecules in the celery stalk attracted the colored water molecules to move by cohesion. C. The water molecules moved by adhesion to the plant fibers. D. The water molecules' high heat capacity caused the colored water molecules to move up the stalk.

B - Because cohesion is the action/property of molecules sticking together.

Which type of organic molecule is formed by strings of amino acids combined using dehydration synthesis? A. Lipids B. Proteins C. Nucleic acids D. Carbohydrates

B - Because proteins are made from a long chain of amino acids with each amino acid being linked to its neighbor through a covalent peptide bond.

Erika performs an experiment and graphs her data, as shown below. Which inference can she make from the data collected? A. Neither enzyme would work well in the human body because the body's internal temperature is outside the range of these enzymes. B. Enzyme A would work well in the human body because its optimal temperature is very close to the body's average temperature. C. Enzyme B would work well in the human body because its optimal temperature is very close to the body's average temperature. D. Enzyme A and B would work equally well in the human body because their optimal temperatures are very close to the body's average temperature.

B - Because the average body temperature is 37℃, and Figure A on the graph is the closest figure to the average body temperature.

Maria, after finding no cold sodas in the refrigerator, placed a can of soda in the freezer. She then proceeded to check her social networking site and forgot about the soda. Later that evening her brother went to get some ice and it was brown. Maria's soda can had split open. What is the best explanation for what happened? A. As the water cooled, it adhered to the can, causing it to split B. When the water froze, the space between hydrogen molecules expanded C. When the water froze, it weakened the molecular bonds in the aluminum can D. As the water cooled, the surface tension of the water decreased and the can collapsed

B - Because water molecules form a crystalline structure maintained by hydrogen bonding when water freezes, which makes the space between hydrogen molecules expand.

Water sticks very well to many materials. Which term relates to this property of water? A. Cohesion B. Adhesion C. Capillary action D. Tension

B - Because while cohesion is sticking to itself, adhesion sticks to other surfaces and/or particles.

Identify the characteristics of water that enable it to show cohesion.

Because it is polar. - it attracts itself because one side is positive and one side is negative.

Which factor makes enzymes well-suited to the role of catalyst in a biochemical reaction? A. Enzymes do not affect the energy of a reaction. B. Enzymes slow down reactions so products can form. C. Enzymes can be reused because they do not permanently get used in the reaction. D. Enzymes can only bind to other enzymes so the same product is formed each time.

C - Because catalysts can be used over and over again, which we discussed in question one.

A florist places a bouquet of white carnations in water containing blue dye. After a time, the flowers turn blue. What process helped the carnations to change color? A. Specific heat B. Surface tension C. Cohesion and adhesion of water molecules D. Formation of covalent bonds between hydrogen and oxygen molecules

C - Because cohesion allows the water to bond together and move up the plant, and adhesion allows the water containing blue dye to stick to the plant (which eventually turns the flowers blue).

Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enable it to move from the roots to the leaves of plants? A. Water expands as it freezes. B. Water is an excellent solvent. C. Water exhibits cohesive behavior. D. Water is able to moderate temperature.

C - Because cohesion is the action of molecules sticking together, and molecules stick together as water moves from the roots to the leaves of the plants.

In many life functions, enzymes work to catalyze reactions. Which statement below is true of all enzymes? A. Enzymes only work in acidic environments. B. Enzymes work by increasing the activation energy. C. An enzyme only catalyzes one specific chemical reaction. D. Enzymes only catalyze the breaking down of substrates.

C - Because enzymes have a specific 3D tertiary structure with a specifically shaped active site which can only bind one substrate to form an enzyme-substrate complex (therefore only being able to catalyze one reaction).

Many enzymes are found in the human body. What is the function of enzymes? A. Enzymes provide the substrates for reactions to occur. B. Enzymes adjust the temperature of the body to allow reactions to occur. C. Enzymes lower the amount of energy needed for certain reactions to occur. D. Enzymes increase the amount of energy available for certain reactions to occur.

C - Because it takes less energy, making it easier for certain reactions to occur.

During the digestion of foods, large molecules are broken down into smaller molecules. For example, starch, a complex carbohydrate, can be directly broken down into A. Fatty acids. B. Amino acids. C. Simple sugar molecules. D. Simple protein molecules.

C - Because simple sugars are the building blocks for carbohydrates.

Water makes up approximately 60% of the human body and plays a vital role in regulating body temperature. Which property of water makes it good at regulating temperature? A. Water is a good solvent. B. Water exhibits strong cohesion. C. Water has a high capacity for heat. D. Water has an unusual crystalline structure in solid form.

C - Because that means the water has the ability to hold a lot of energy, which is vital when it comes to a high capacity of heat.

How do lipids mainly function in living organisms? A. Lipids act as transmitters of genetic information. B. Lipids act as catalysts for chemical reactions. C. Lipids are sources of stored energy. D. Lipids are inorganic compounds.

C - Because the excess energy from the food we eat is digested and incorporated into adipose tissue, or fatty tissue (which makes up lipids).

Water is one of the most powerful natural solvents known. For instance, salt, sugar, glucose, and nitrates all dissolve readily in water. The solvent property of water is vital for life because many biochemical reactions take place only within aqueous solutions. What is another reason why the solvent property of water is important to life? A. Water is able to cool the body when it evaporates. B. Water is able to flow past obstacles present in the bowel. C. Water can transport nutrients throughout the body. D. Water can increase the concentration of toxic substances.

C - Because when the nutrients are dissolved, they can move.

Identify the macromolecule made from the monomer below.

Carbohydrate - Because there's H2O (Water) and Carbon in it, which makes carbohydrates.

The diagram below shows the structure for part of a molecule. Identify the subunits of the molecule shown.

Carbohydrates - Because there is Carbon and H2O.

One of the unique characteristics of water is its ability to maintain a constant temperature within large aquatic systems. Why is this important to an aquatic environment? A. Aquatic organisms cannot survive in warm water environments. B. Most aquatic organisms cannot survive in cold water environments. C. Aquatic organisms can only survive within a very small range of water temperatures. D. Most aquatic organisms cannot survive a rapid increase or decrease in water temperature.

D - Because it would be difficult for the aquatic organisms to adapt to the change in temperature so quickly, especially if they aren't already adapted to it.

Four different types of macromolecules and their characteristics are listed below. What type of macromolecule is D? A. Carbohydrate B. Lipid C. Nucleic acid D. Protein

D - Because proteins (enzymes) catalyze chemical reactions, and proteins are all about structure, storage, and transport.

Which group of macromolecules includes enzymes which help regulate an organism's metabolism? A. Carbohydrates B. Lipids C. Nucleic acids D. Proteins

D - Because we used the information in Question One to transfer our information over to this question.

Which of the following will affect an enzyme's rate of reaction? A. l and II only B. l and lll only C. ll and lll only D. l, ll, and lll

D - Because while the change in pH and extreme temperature negatively affect an enzyme's rate of reaction, the substrate concentration will positively affect it and speed it up.

A student studied the location of single celled photosynthetic organisms in a lake for a period of several weeks. The depth at which these organisms were found at different times of the day varied greatly. Some of the data collected are shown in the table below. State a valid inference based on the data.

Depth of the photosynthetic organisms changes with the intensity of light.

Lipids are one of the macromolecules made from fatty acids. These molecules are used for both long term and short term energy storage. Identify the lipid used for long term energy storage in both plants and animals.

Glycerin - Because it's a liquid form for plants and solid form for animals.

This macromolecule has been associated a great deal with muscle building and is often used during pre- and post-workouts to replenish the body of the necessary nutrients needed to promote increased muscle function and growth. Identify the macromolecule made of a chain of amino acids that allows the muscles to contract making body movement possible.

Protein - Because they're made of amino acids and also there are about 75 million stereotypes about bodybuilders and protein.

The diagram below shows a water molecule. Describe why the structure of a water molecule makes it a good solvent.

The ability of making hydrogen bonds that dissolve. It's positive and negative like a magnet, making it polar (polarity).

Identify the property of water that assists your body from being damaged by changes in temperature and explain how it does that.

The ability to store heat - It helps prevent us from overheating.

Compare the lock-and-key and induced-fit models of enzyme activity.

The main difference between induced fit and lock-and-key model is that in the induced fit model, the active site of the enzyme does not completely fit to the substrate whereas in the lock and key model, the active site of the enzyme is the complement of the substrate and hence, it precisely fits to the substrate.

Describe the four levels of structure of a protein.

The primary (first) structure is the sequence of amino acids that make up a polypeptide chain, while the secondary (second) structure refers to regular, repeated patterns of folding of the protein backbone. The tertiary (third) structure refers to the overall folding of the entire polypeptide chain into a specific 3D shape, and the quaternary (fourth) structure describes the way in which the different subunits are packed together to form the overall structure of the protein.

The diagram below represents the synthesis of nutrients to form organic compounds. Identify the substances most likely represented by the letter X.

The substances most likely represented by the letter X are carbohydrates such as sugars and starches.

One unique property of water is its high surface tension. Identify a situation when this property is useful to living things?

Water bugs sticking to rivers/waters

Identify the class of nutrients to which the molecules of fats and oils belong.

Lipids, which are insoluble in water (unlike carbohydrates).