1. Photosynthesis and Respiration Study Guide
Answer Key

2. Enzymes
Named for the reaction they help. Always end in “-ase.” Ex. Lactase breaks down lactose in dairy.
Enzymes are proteins.

3. Enzymes
Enzyme specificity-there is a specific enzyme for each specific reaction.
Denature means the enzyme loses shape and can no longer function. Extreme temperature and pH can cause this!
Enzymes work by lowering
the activation energy of the reaction.
By doing this, the reaction
can happen faster.

4. Photosynthesis
The overall function of photosynthesis is to convert radiant energy to chemical energy. In other words, it is a reaction that converts sunlight into glucose.
Green light is least effective because it is reflected, not absorbed, by the plant. As a result, plants appear green.

5. Photosynthesis
It is beneficial for leaves to have more chloroplasts because the leaves are exposed to sunlight.
Photosynthesis can only occur in the presence of light.
Producers are vital to the consumers survival because they convert radiant energy to chemical. Without them, we
would not be able to
consume the glucose
needed for respiration.

6. Cellular Respiration
The overall function of cellular respiration is to generate ATP.
The mitochondria allows for large production of ATP. This is why aerobic respiration is more efficient than anaerobic.
All eukaryotic organisms carry out respiration.

7. Comparing Photosynthesis and Respiration
Photosynthesis
Respiration
Overall Function?
 To convert radiant energy to chemical (glucose)
To generate ATP
Which Organelle?
 Chloroplast
Mitochondria
Which Organisms?
Green plants, some bacteria (any organism with chloroplast)
All Eukaryotes
When?
 Only in presence of light
All the time
REACTANTS PRODUCTS
Photosynthesis
Respiration

8. Anaerobic vs. Aerobic Respiration
Anaerobic respiration occurs without oxygen.
Aerobic respiration is more efficient because it creates more ATP per glucose molecule
Aerobic=38 ATP Anaerobic=2 ATP
Aerobic respiration occurs in the mitochondria.
Anaerobic respiration occurs in the cytoplasm.
Muscle cells will perform anaerobic respiration in the event that there is a shortage of oxygen.

9. Comparing Fermentation
Alcoholic Fermentation
Lactic Acid Fermentation
In what cells?
 Bacteria, yeast
Bacteria, Muscle cells
What is produced?
 Ethanol (alcohol)
Lactic Acid
Alcoholic fermentation was occurring in the bag with yeast and sugar. We could see carbon dioxide filling the bag, and can assume ethanol was present as well.
In the event of a shortage of oxygen, your muscle cells will convert to anaerobic lactic acid fermentation. The byproduct, lactic acid, causes muscle cramps.

10. Which of the following is true of enzymes?
They act on nonspecific, randomly chosen substrates
After a reaction, they cannot be reused
They can speed up metabolic processes in the body
They cannot change the shape

11. At which site on an enzyme do substrates bind and react?
Reaction site
Regulatory site
Active site
Catalysis site

12. Cellular respiration uses one molecule of glucose to produce:
2 ATP
34 ATP
36 ATP
38 ATP

13. To which class of organic compounds do enzymes belong?
Proteins
Fatty acids
Nucleic acids
Monosaccharides

14. Which is a difference between aerobic respiration and anaerobic respiration?
Anaerobic respiration requires oxygen
Anaerobic respiration does not require oxygen
Anaerobic respiration occurs only at the cellular level
Anaerobic respiration only occurs outside of the cell

15. How does an enzyme speed up chemical reactions?
By absorbing energy
By releasing energy
By decreasing the energy needed
By increasing the energy needed

16. Enzymes become hormones Enzymes become denatured
Many enzymes in the human body function best at 37 degrees Celsius. What is the most likely result of a great increase in body temp?
Enzymes become hormones
Enzymes become denatured
Enzymes become more active
Enzymes become more sluggish

17. Aerobic respiration results in less energy
How does the amount of energy resulting from fermentation compare with that of aerobic respiration?
Aerobic respiration results in less energy
Aerobic respiration results in more energy
Each process results in equal energy
Each process results in variable amounts of energy

18. Which most directly controls the rate at which food is broken down to release energy?
Enzymes
Hormones
Nucleic acids
Vitamins

19. Which of these is a product of photosynthesis and a requirement for cellular respiration?
Carbon dioxide
Glucose
Water
Sunlight

20. Which is a waste product of photosynthesis?
Carbon dioxide
Glucose
Oxygen
Water