Objectives

Quiz 1:

1. From a molecular formula, be able to determine how many atoms of different elements are found in a particular molecule.

2. Be able to identify reactants and products in a chemical reaction, and understand that chemical reactions make or break chemical bonds.

3. Identify carbon as the most important atomic element to the chemistry of living things is carbon. Other important elements are hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

4. Explain the importance of water in living things.

5. Identify the following for each of the four classes of biomacromolecules: Monomer, polymer, elemental composition, key examples, and primary functions in a cell or organism.

6. Explain how enzymes function as biological catalysts, in terms of activation energy.

7. Explain the effects of temperature and pH on enzyme action.

Quiz 2:

8. Be able to describe how ATP/ADP are used to transfer energy within a cell vs how glucose is used to store energy.

9. Distinguish between autotrophs and heterotrophs in terms of whether they perform photosynthesis and/or cellular respiration.

10. Describe the purpose, cellular location, reactants, and products of photosynthesis.

11. Describe the purpose, cellular location, reactants, and products of cellular respiration.

12. Explain how photosynthesis and cellular respiration connect to each other.

13. Distinguish between aerobic respiration vs. anaerobic fermentation (alcohol or lactic acid).

Vocabulary

Quiz 1:

Acid

Activation energy

Active site

Amino acid

Atom

Base

Biomacromolecule

Bond

Carbohydrate

Carbon

Catalyst

Cellulose

Chemical energy

Chemical reaction

Cholesterol

Denaturation

Disaccharide

DNA

Element

Endergonic reaction

Energy

Enzyme

Enzyme-Substrate Complex

Exergonic reaction

Fatty acid

Free energy

Glucose

Glycerol

Glycogen

Hydrogen

Hydrogen bond

Lipid

Macromolecule (or Biomacromolecule)

Monomer

Monosaccharide

Nitrogen

Nonpolar molecule

Nucleic acid

Nucleotide

Organic (i.e. Organic chemistry, organic molecule)

Oxygen

pH

Phospholipid

Polar molecule

Polymer

Polypeptide

Polysaccharide

Product

Protein

Reactant

RNA

Starch

Substrate

Water

Quiz 2:

Aerobic

Anaerobic

ADP (adenosine diphosphate)

ATP (adenosine triphosphate)

Autotroph

Cellular respiration

Chlorophyll

Chloroplast

Fermentation

Glucose

Glycolysis, Krebs Cycle (a.k.a. Citric Acid Cycle), and Electron Transport Chain

Heterotroph

Light-dependent and Light-Independent Reactions

Photosynthesis

Textbook Reference

These are the sections in the textbook (Biology: The Core) that cover the material in this unit.

Quiz 1:

2.1: All life is made of molecules, which are made of atoms

2.2: All matter consists of chemical elements

2.3: Atoms are composed of subatomic particles

2.4: Atoms are held together by chemical bonds

2.5: The structure of water gives it unique properties

2.6: pH is a measure of the acidity of a solution

2.7: Life on Earth is based on carbon

2.8: Most biological macromolecules are polymers

2.9: Carbohydrates are composed of monosaccharides

2.10: Lipids are a diverse group of hydrophobic molecules

2.11: Your diet contains several different kinds of fats

2.12: Proteins perform many of life's functions

2.13: Enzymes speed chemical reactions

Quiz 2:

4.1: Energy can be converted from one form to another

4.2: Energy flows through an ecosystem

4.3: Within chloroplasts, the energy of sublight is used to produce sugars

4.4: Photosynthesis occurs in two linked stages

4.7: In cellular respiration, oxygen is used to harvest energy stored in sugar

4.9: In fermentation, energy is harvested from sugar without oxygen

4.10: Cellular respiration is a central hub of many of life's metabolic processes

Relevant Files

Feel free to take notes directly on/in it! Either copy, download, or print as handouts and bring to class.  It's split into two files, the first with the material on quiz #1, the second with the material on quiz #2.

Sample MCAS Questions

The following is a list of biochemistry questions that appeared on previous versions of the MCAS exam. They are presented to you here for use in your own personal study habits, and also to clarify for you what MCAS multiple choice and essay questions look like. Take particular notice of how MCAS questions are almost always based around an example, story, or scenario, rarely simply asking you to supply a definition.

Quiz 1:

1. Which of the following lists of elements contains the most common elements in organic compounds?

A. Calcium, iron, and potassium

B. Carbon, hydrogen, and oxygen

C. Chlorine, phosphorus, and sodium

D. Copper, magnesium, and sulfur

2. 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

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

A. hydrogen

B. iron

C. potassium

D. sodium

4. 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 and 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

5. A diagram of an organic molecule is below.

Which element is found at positions marked by the dots in the diagram?

A. Carbon

B. Nitrogen

C. Phosphorus

D. Sulfur

6. In the human body, fibrinogen is necessary for sealing cuts and stopping the loss of blood. Since fibrinogen is made of chains of amino acids, it is an example of which type of organic molecule?

A. carbohydrate

B. protein

C. fatty acid

D. nucleic acid

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

A. nucleic acids - digest dead cells

B. lipids - give quick energy to cells

C. carbohydrates - store genetic information

D. proteins - provide structure in skin, hair, and nails

8. 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. lipids

C. nucleic acids

D. proteins

9. The diagram below shows the molecular structure of glucose.

Glucose is a simple carbohydrate that is important to living organisms.

a. Describe the primary function of glucose in cells.

b. Simple sugars like glucose can be used to make larger organic molecules. Identify two larger molecules made from simple sugars.

c. Identify a specific cellular process that would be affected by a glucose shortage, and discuss the effects of the shortage on the process you identified.

10. 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

11. When lactose is digested by the human body, each lactose molecule is broken down into smaller molecules. To which of the following categories of molecules do these smaller molecules belong?

A. amino acids

B. monosaccharides

C. nucleic acids

D. polypeptides

12. Lemurs’ bodies are adapted to efficiently store energy for times when food is scarce. This adaptation may help to explain how lemur ancestors survived the trip across the Mozambique Channel from mainland Africa to Madagascar.

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

13. Which of the following units are repeatedly joined together to form a strand of DNA?

A. amino acids

B. fatty acids

C. nucleotides

D. polysaccharides

14. Students in a biology laboratory are monitoring the rate at which hydrogen peroxide breaks down to produce water and oxygen gas. They begin monitoring a sample of hydrogen peroxide and then add catalase, an enzyme that speeds up its breakdown. Their data are shown in the table below.

Time

(min)

Rate of Hydrogen

Peroxide Breakdown

(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

15. Some bacteria live in hot springs. Their cells contain enzymes that function best at temperatures of 70°C or higher. At a temperature of 50°C, how will the enzymes in these bacterial cells most likely be affected?

A. The enzymes will be destroyed by lysosomes.

B. The enzymes will lose their bond structure and fall apart.

C. The enzymes will not require less energy to function than at 70°C.

D. The enzymes will not increase the rate of reaction as much as they would at 70°C.

16. 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

17. In the human digestive system, the enzyme trypsin acts on proteins. The optimal temperature for the enzyme is approximately 40°C.

Which of the following graphs shows how the activity of the enzyme most likely relates to the temperature of the reaction environment?

18. 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 the reactants from solid to liquid during the reactions.

C. The reactions take up too much space in the cell if the enzyme is missing.

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

19. Baby food manufacturers sometimes use protease in their products. Proteases catalyze the breakdown of proteins in these foods, making digestion easier for infants. Proteases are what kind of molecule?

A. Enzymes

B. Fatty acids

C. Hormones

D. Monosaccharides

20. 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 sugar

B. an enzyme

C. a nucleotide

D. an amino acid

21. The graph below shows the rate of activity for the enzyme catalase at different temperatures. Catalase helps convert hydrogen peroxide to oxygen and water. The rate of catalase activity is directly related to the percent increase in oxygen.

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.

Quiz 2:

22. Which of the following processes releases primarily oxygen into the atmosphere?

A. combustion

B. osmosis

C. photosynthesis

D. respiration

23. Mallory has four aquatic plants of the same size and species. She submerges each plant in a separate beaker filled with 200 mL of water. She then sets each beaker under a different intensity of light. Mallory observes that, of the four plants, the plant in the beaker under the most intense light gives off the most gas bubbles in a 20 min period.

Which of the following statements best explains Mallory's observation?

A. Cells decompose most quickly under the most intense light.

B. Water evaporates from plants faster under the most intense light.

C. Photosynthesis occurs at the higher rate under the most intense light.

D. Gases in the leaves of the plants expand most under the most intense light.

24. All organisms have ways to produce ATP. Which of the following statements describes why ATP is a critical compound for all cells?

A. It causes mitosis to begin.

B. It is an energy-transfer molecule.

C. It is a major component of cell membranes.

D. It carries information from DNA to the ribosomes.

25. Energy for most chemical reactions in cells is supplied by which of the following molecules?

A. ATP

B. DNA

C. adrenaline

D. hemoglobin

26. Some bacteria can perform photosynthesis. These bacteria must therefore contain which of the following in their membranes?

A. Chlorophyll

B. Glucose

C. Mitochondria

D. Ribosomes

27. An equation for a biochemical reaction is shown below.

Which of the following happens during this reaction?

A. Energy from ATP is used to make glucose.

B. ADP adds a high-energy bond to its structure.

C. ADP is metabolized to provide oxygen to a cell.

D. Energy is stored in the molecule ATP for future use.

28. Which process do the animals in the food web use to convert energy from food into ATP?

A. Cellular respiration

B. Osmosis

C. Photosynthesis

D. Transcription

29. Which type of milk, per serving, will theoretically yield a greater amount of ATP in the human body, and what is the reason for this?

A. dairy milk, because it contains vitamin C

B. soymilk, because it contains no cholesterol

C. dairy milk, because it has larger amounts of sugar and fat

D. soymilk, because it has larger amounts of vitamins A and D

30. Which of the following most likely happens in the cells of a person running in the Boston Marathon?

A. The respiration rate increases to produce more ATP.

B. The replication rate increases to produce more DNA.

C. The photosynthesis rate increases to produce more sugars.

D. The cell division rate increases to produce more muscle fibers.

31. Both photosynthesis and cellular respiration involve all of the following EXCEPT

A. chlorophyll

B. glucose

C. oxygen

D. water

32. When Lance goes jogging, his heart rate increases to pump blood faster and supply his muscles with more oxygen. Which of the following helps to maintain homeostasis in response to this increase in heart rate?

A. An increase in digestion

B. An increase in respiration

C. An increase in perspiration

D. A decrease in bone growth

33. Which of the following statements correctly describes the processes of photosynthesis and cellular respiration?

A. Photosynthesis and cellular respiration occur in the same organelle.

B. Photosynthesis and cellular respiration are performed by all organisms.

C. Photosynthesis produces carbon dioxide, and cellular respiration uses carbon dioxide.

D. Photosynthesis stores energy for cells, and cellular respiration releases energy for cells.

34. The graph below shows the change in blood glucose level during prolonged exercise.

Which of the following explains the change in blood glucose level shown in the graph?

A. Glucose was broken down to produce ATP for energy.

B. Glucose was diffused from muscle cells into the bloodstream.

C. Proteins combined with glucose to produce ADP for energy.

D. Polysaccharides were made from glucose in metabolic pathways.

35. A mitochondrion has two membranes. The inner membrane is highly folded, as shown in the diagram.

The folds greatly increase the membrane's surface area. This improves the ability of the mitochondrion to do which of the following?

A. Move the cell through water

B. Digest metabolic wastes in this organelle

C. Convert solar energy to chemical energy

D. Produce ATP during cellular respiration

ANSWERS

1. B

2. C

3. A

4. B

5. A

6. B

7. D

8. B

9. Example answers of high and low quality can be found here.

10. C

11. B

12. A

13. C

14. B

15. D

16. A

17. D

18. D

19. A

20. B

21. A 

22. C

23. C

24. B

25. A

26. A 

27. A

28. A

29. C

30. A

31. A

32. B

33. D

34. A

35. D