Bioenergetics

Question 1

What is the equation for photosynthesis and how how is it an endothermic reaction

Answer 1

carbon dioxide + water —> glucose + oxygen
To produce glucose molecules energy is required because the reaction is endothermic. The energy is supplied by sunlight and absorbed by chlorophyll

Question 2

How is temperature a limiting factor in photosynthesis

• increase
• limit

Answer 2

• As the temperature increases so does the rate of photosynthesis as more energy is provided for the reaction.
• As the temperature approaches 45 rate of reaction drops to zero as enzymes become denatured

Question 3

How is carbon dioxide concentration a limiting factor in photosynthesis

• increase
• limit

Answer 3

• As concentration of CO2 increases so does the rate of photosynthesis as it is needed for the reaction
• after reaching a certain point an increase in CO2 has no effect so it is no longer a limiting factor

Question 4

How is light intensity a limiting factor of photosynthesis

Answer 4

• As light intensity increases so does rate of reaction as more energy is provided
• after reaching a certain point an increase in light intensity has no effect so is no longer a limiting factor

Question 5

What is glucose used for in plants and what can it be converted into

Answer 5

-used by the plant during respiration to provide energy
converted to:
-insoluble starch
-cellulose to strengthen the cell walls
-to produce proteins from glucose as well as nitrate ions from soil

Question 6

Why is respiration important in living organisms

Answer 6

• for chemical reactions to build larger molecules
• for movement
• to keep warm

Question 7

what are the equations for aerobic

Answer 7

glucose + oxygen —> carbon dioxide + water

Question 8

what is the equation for anaerobic respiration on plants and why does it transfer less energy

Answer 8

glucose —> lactic acid

the glucose is not completely broken down so it transfers much less energy

Question 9

what is the equation for anaerobic respiration in plants, yeast and alcohol

Answer 9

glucose —> ethanol + carbon dioxide

in yeast cells this is called fermentation

Question 10

What is metabolism and why is energy needed

-(enzymes)

Answer 10

metabolism is the sum of all the chemical reactions in a cell or in the body
these reactions are controlled by enzymes that need a transfer of energy (respiration) to make new molecules

Question 11

what new molecules to metabolism reactions make

Answer 11

• conversion of glucose to starch, glycogen and cellulose
• formation of lipid molecules
• breakdown of excess proteins into urea