MCAS Guide Page 2

Review the first page of your guideBioChemistry

Elements

• There are 6 you must know:– Carbon (C)– Hydrogen (H)– Oxygen (O)– Nitrogen (N)– Phosphorus (P)– Sulfur (S)

• Remember CHONPS– Or “Cars Hide Out Near Parking Spaces”

MACROMOLECULES

• There are 4 types of macromolecules : Carbohydrates, Lipids, Proteins and Nucleic Acids

• For each of the four you should know– Their monomer (pieces they are made of)– Examples of them – Their job or function (most important)

ENZYMES

• Enzymes are a special type of protein

• The job of an enzyme is to break things down, or make reactions happen faster by lowering the activation energy

• The names of enzymes end in “-ase”

PRACTICE

• After reading over page 1 of your study guide, try these real MCAS questions.

• After each question you will be shown the correct answer with hints to see how to know.

• Take your time and read each carefully– The point is to practice and eventually find all of

them easy!!!

Resistance to antibiotics results from variations in the genetic code of Streptococcus pneumoniae. Which type of molecule encodes genetic information in Streptococcus pneumoniae?

A. carbohydrateB. fatty acidC. nucleic acidD. protein

Resistance to antibiotics results from variations in the genetic code of Streptococcus pneumoniae. Which type of molecule encodes genetic information in Streptococcus pneumoniae?

C. nucleic acid

See this is a very hard question to read, but by knowing to look for key phrases, it can be easy. The job of Nucleic Acids is to encode genetic information!!!

A student is preparing to run in a school track competition. For the quickest source of energy, the student should eat a food that contains a high percentage of

A. carbohydrates.B. fat.C. proteins.D. sodium.

A student is preparing to run in a school track competition. For the quickest source of energy, the student should eat a food that contains a high percentage of

A. carbohydrates.

Carbohydrates (including sugar) are the quickest source of energy for your body, that’s their job!!

An amoeba in a pond engulfs and consumes a paramecium. The amoeba uses which of the following to quickly break down the organic molecules in the paramecium?

A. enzymesB. glucoseC. polysaccharidesD. water

An amoeba in a pond engulfs and consumes a paramecium. The amoeba uses which of the following to quickly break down the organic molecules in the paramecium?

A. enzymes

The job of an enzyme is to break things down, or make reactions happen faster by lowering the activation energy

Students digging near their school unearthed four objects. One of the objects was part of the exoskeleton of an insect. The table below shows the results of a chemical analysis of the objects.Object Chemical Composition

W chlorine, sodiumX oxygen, siliconY carbon, hydrogen, nitrogen, oxygenZ aluminum, silicon, oxygen, hydrogen

Based on the chemical analysis, which object is most likely from the exoskeleton? A. object W B. object X C. object Y D. object Z

Object Chemical CompositionW chlorine, sodiumX oxygen, siliconY -------- carbon, hydrogen, nitrogen, oxygenZ aluminum, silicon, oxygen, hydrogen

Based on the chemical analysis, which object is most likely from the exoskeleton?

C. object Y Again, there is a lot to read, but by looking for shortcuts yourecognize the 4 of the 6 elements you must know !!! (and none that are not on the list)

Vitamin D is an organic molecule that regulates the absorption of calcium by the body. Which of the following elements is most common in a molecule of vitamin D?

A. aluminumB. carbonC. magnesiumD. sodium

Vitamin D is an organic molecule that regulates the absorption of calcium by the body. Which of the following elements is most common in a molecule of vitamin D?

B. carbon

Only one of the answers is from the list of 6 elements you must know!!!

Which of the following roles does an enzyme play when the body processes sucrose (table sugar) into glucose and fructose?

A. An enzyme decreases the body’s need for sucrose.B. An enzyme increases the amount of sucrose available.C. An enzyme increases the rate at which the sucrose breaks down.D. An enzyme decreases the amount of fructose and glucose product available.

Which of the following roles does an enzyme play when the body processes sucrose (table sugar) into glucose and fructose?

C. An enzyme increases the rate at which the sucrose breaks down.

The job of an enzyme is to break things down, or make reactions happen faster by lowering the activation energy

What do disaccharides, such as sucrose, and polysaccharides, such as starch, have in common?

A. They are lipids made of fatty acids.B. They are proteins made of amino acids.C. They are nucleic acids made of nucleotides.D. They are carbohydrates made of simple sugars.

What do disaccharides, such as sucrose, and polysaccharides, such as starch, have in common?

D. They are carbohydrates made of simple sugars.

Monomers of carbohydrates are monosaccharides, also look for words that end in “-ose” (sucrose). They are names for sugars.

The role of an enzyme in a chemical reaction is to change which of the following?

A. the type of reactionB. the activation energy of the reactionC. the pH at which the reaction occursD. the temperature at which the reaction occurs

The role of an enzyme in a chemical reaction is to change which of the following?

B. the activation energy of the reaction

The job of an enzyme is to break things down, or make reactions happen faster by lowering the activation energy (the energy to start a reaction)

Which type of molecule in the yolk of a chicken egg provides the most energy for a developing chick?

A. lipidB. nucleic acidC. saltD. water

Which type of molecule in the yolk of a chicken egg provides the most energy for a developing chick?

A. lipid

Lipids job is to store energy (in fats)

Fatty acids are one of the products that result from the action of lipase in the digestive system. What is one way that fatty acids are used in the body?

A. for storing energyB. for encoding genetic informationC. as the building blocks of antibodiesD. as the building blocks of hemoglobin

Fatty acids are one of the products that result from the action of lipase in the digestive system. What is one way that fatty acids are used in the body?

A. for storing energy

Fatty acids (fats) are the monomer for lipids. The job of lipids is to store energy!!

Scientists have found geysers on one of Saturn’s moons. The geysers release water vapor containing complex organic compounds, which may indicate the presence of life.

Which of the following elements is most likely abundant in the organic compounds in the water vapor?

A. carbonB. chlorineC. ironD. zinc

Scientists have found geysers on one of Saturn’s moons. The geysers release water vapor containing complex organic compounds, which may indicate the presence of life.

Which of the following elements is most likely abundant in the organic compounds in the water vapor?

A. carbon

A long question to read, but only one answer that is from the 6 elements you must know!!

Which of the following is the main reason that humans need to include carbohydrates in their diet?

A. Carbohydrates are broken down in cells for energy.B. Carbohydrates combine to form many different proteins.C. Carbohydrates act as catalysts to speed up chemical reactions.D. Carbohydrates are the building blocks for cell growth and repair.

Which of the following is the main reason that humans need to include carbohydrates in their diet?

A. Carbohydrates are broken down in cells for energy.

The job of carbohydrates (sugars) is to give quick energy

Acetylcholine is an important chemical signal in the nervous system. Once acetylcholine is released, it is quickly broken down into other chemicals because of the activity of cholinesterase.Cholinesterase is which of the following?

A. a hormoneB. a lipidC. an enzymeD. an organelle

Acetylcholine is an important chemical signal in the nervous system. Once acetylcholine is released, it is quickly broken down into other chemicals because of the activity of cholinesterase.Cholinesterase is which of the following?

C. an enzyme

Enzyme names usually end in “-ase”. Even though you may not understand what the question says, look for the “-ase” (cholinesterase) as a key. Also job of enzymes is to break things down.

Based on the graph, which of the following conclusions can be made about the functioning of catalase?

A. Catalase works best at 34 C.B. Catalase is destroyed at 34 C.C. Catalase cannot function at 51 C.D. Catalase functions most efficiently at 51 C.

Based on the graph, which of the following conclusions can be made about the functioning of catalase?

A.Catalase works best at 34 C.

Read the graph, look at its highest point, line up at 34 C

Which of the following elements is most common in the tissues of plants?

A. hydrogenB. ironC. potassiumD. sodium

Which of the following elements is most common in the tissues of plants?

A. hydrogen

Only answer from the 6 elements you must know!!

Which element is the main component of all organic molecules?

A. carbonB. nitrogenC. potassiumD. sodium

Which element is the main component of all organic molecules?

A. carbon

Although Carbon and Nitrogen are both on the list of 6 elements, Carbon is the most important. If there is more than 1 of the 6 listed, Carbon is the best answer.

One category of organic compounds contains molecules composed of long hydrocarbon chains. The hydrocarbon chains may be saturated or unsaturated.

Which of the following categories of organic compounds contains these molecules?A. carbohydrates

B. lipidsC. nucleic acidsD. proteins

One category of organic compounds contains molecules composed of long hydrocarbon chains. The hydrocarbon chains may be saturated or unsaturated.

Which of the following categories of organic compounds contains these molecules?

B. lipids

This is a tough question, but it describes the picture of lipids (like an “E”) and the long chains it has. Also you might recognize saturated and unsaturated as types of fats and fats are lipids

Some bacteria contain a substance called nitrogenase. Nitrogenase catalyzes the chemical reaction that converts atmospheric nitrogen (N2) into ammonia (NH3).

Nitrogenase is an example of which of the following?

A. a sugarB. an enzymeC. a nucleotideD. an amino acid

Some bacteria contain a substance called nitrogenase. Nitrogenase catalyzes the chemical reaction that converts atmospheric nitrogen (N2) into ammonia (NH3).

Nitrogenase is an example of which of the following?

B. an enzyme

“Catalyze” means “speeds up” , also name ending in “-ase” is a big clue.

Which of the following categories of organic molecules is correctly paired with one of its functions?

A. nucleic acids—digest dead cellsB. lipids—give quick energy to cellsC. carbohydrates—store genetic informationD. proteins—provide structure in skin, hair, & nails

Which of the following categories of organic molecules is correctly paired with one of its functions?

D. proteins—provide structure in skin, hair, &

nails

Know the job of each of the 4 organic molecules. Proteins job is to build muscle, skin, hair etc.

Which of the following best explains why enzymes are necessary for many cellular reactions?

A. Enzymes supply the oxygen necessary for the reactions.

B. Enzymes change reactants from solid to liquid during the reactions.

C. The reactions take up too much space in the cell if enzymes are missing.

D. The reactions are too slow to meet the needs of the cell if enzymes are missing.

Which of the following best explains why enzymes are necessary for many cellular reactions?

D. The reactions are too slow to meet the needs of the cell if enzymes are missing.

The job of an enzyme is to break things down, or make reactions happen faster by lowering the activation energy

Which of the following types of molecules are primarily used for long-term energy storage in the lemur?

A. lipids B. monosaccharides C. nucleic acids D. proteins

Which of the following types of molecules are primarily used for long-term energy storage in the lemur?

A. lipids

This question also has a long paragraph to read about lemurs, but you don’t need to know anything about lemurs to see this.

The graph below shows how the activity of an enzyme changes over a range of pH values.

Which of the following conclusions is supported by the data?

A. The optimum pH of the enzyme is 6.6. B. The optimum pH of the enzyme is 5.8. C. The enzyme’s activity is greater around pH 8.0 than

around pH 5.0. D. The enzyme’s activity continually increases as pH

increases from 5.0 to 9.0.

Which of the following conclusions is supported by the data? A. The optimum pH of the enzyme is 6.6.

Read the graph, look for which answer best matches what you see, there is no way to study for this, just don’t be afraid of it

A scientist is analyzing a sample of tissue from a plant. Which of the following elements will be most abundant in the sample?

A. zinc and copper B. sodium and chlorine C. carbon and hydrogen D. magnesium and calcium

A scientist is analyzing a sample of tissue from a plant. Which of the following elements will be most abundant in the sample?

C. carbon and hydrogen Only answer with 2 elements from the list of 6 you

must know!!!

Baby food manufacturers sometimes use proteases in their products. Proteases catalyze the breakdown of the proteins in these foods, making digestion easier for infants.

Proteases are which of the following types of molecules?

A. enzymes B. fatty acids C. hormones D. monosaccharides

Baby food manufacturers sometimes use proteases in their products. Proteases catalyze the breakdown of the proteins in these foods, making digestion easier for infants.

Proteases are which of the following types of molecules?

A. enzymes

Ovalbumin is a protein found in eggs. Which of the following best describes the molecular structure of ovalbumin?

A. a group of six carbon atoms joined in a ring B. a chain of amino acids folded & twisted into a

molecule C. a set of three fatty acids attached to a molecule

of glycerol D. a sequence of nitrogenous bases attached to a

sugar-phosphate backbone

Ovalbumin is a protein found in eggs. Which of the following best describes the molecular structure of ovalbumin?

B. a chain of amino acids folded & twisted into a

molecule

Proteins are made of amino acids,

A diagram of an organic molecule is below.

Which element is found at the positions marked by the dots (•) in the molecule?

A. carbon B. nitrogen C. phosphorus D. sulfur

A diagram of an organic molecule is below.

Which element is found at the positions marked by the dots (•) in the molecule?

A. carbon

All 4 answers are from the list of 6 elements! If there is more than one answer, Carbon is the correct answer.

Time Rate of Hydrogen Peroxide Breakdown(min) (molecules per min)

0.0 0.000 0.5 0.030 1.0 0.032 1.5 4,970,000.000 2.0 5,001,000.000 2.5 4,985,300.000 3.0 5,021,700.000

Based on the data in this table, during which of the following time periods did the students add the catalase to the hydrogen peroxide?

A. between 0.0 and 0.5 min B. between 1.0 and 1.5 min C. between 2.0 and 2.5 min D. between 2.5 and 3.0 min

Time Rate of Hydrogen Peroxide Breakdown(min) (molecules per min)

0.0 0.000 0.5 0.030 1.0 0.032 1.5 4,970,000.000 2.0 5,001,000.000 2.5 4,985,300.000 3.0 5,021,700.000

B. between 1.0 and 1.5 min

Don’t overthink it, just look at what time the big change happens

If scientists search other planets for possible life, they are likely to focus on the presence of molecules containing which of the following elements?

A. carbon B. iron C. potassium D. sodium

If scientists search other planets for possible life, they are likely to focus on the presence of molecules containing which of the following elements?

A. carbon

This is too easy right?

Many land plants store energy in starch. When energy is needed, the starch molecules can be broken down quickly.

This chemical reaction produces which of the following?

A. amino acids B. lipids C. monosaccharides D. RNA chains

Many land plants store energy in starch. When energy is needed, the starch molecules can be broken down quickly.

This chemical reaction produces which of the following?

C. monosaccharides

Monosaccharides (sugars) are the monomers of carbohydrates – used for quick energy.

In red blood cells, the compound carbonic anhydrase increases the rate at which carbon dioxide is converted to bicarbonate ions for transport in the blood. In red blood cells, carbonic anhydrase acts as which of the following?

A. an enzyme B. a hormone C. a lipid D. a sugar

In red blood cells, the compound carbonic anhydrase increases the rate at which carbon dioxide is converted to bicarbonate ions for transport in the blood. In red blood cells, carbonic anhydrase acts as which of the following?

A. an enzyme The job of an enzyme is to break things down, or

make reactions happen faster by lowering the activation energy. Also you have the name ending in “-ase” (anhydrase)