3.2.3 Cellular Respiration

Question 1

cellular respiration

Answer 1

series of chemical reactions that transfer energy stored in bonds of glucose to energy stored in bonds of ATP (smaller quantities that are converted to ADP to release energy into cell)

Question 2

reactants come from

Answer 2

• breathe in oxygen through lungs which diffuses into blood and then cells
• digest food and glucose diffuses from intestines into blood then cells
• producers make their own oxygen and glucose by photosynthesis

Question 3

overall equation

Answer 3

6O2+C6H12O6->(32 ATP) 6CO2+6H2O

Question 4

glycolysis

Answer 4

• in cytosol
• breaks down glucose (6C) into 2 pyruvate (3C)
• energy released is used to convert 2ADP->2ATP
• electrons and H+ released and picked up, NAD+->NADH

Question 5

krebs cycle

Answer 5

• in matrix
• pyruvate (3C) broken down into acetyl-coA (2C) and CO2 (1C), 2NAD+->NADH
• energy used to convert 2ADP->2ATP
• electrons and H+ released and picked up 6NAD+->6NADH, 2FAD+->2FADH2
• 4CO2

Question 6

electron transport chain

Answer 6

• in cristae
• FADH2 and NADH donate 2 e- and 4H+ to cytochrome proteins in cristae
• electrons pulled through cytochromes to O2 which accepts e-
• H+ accumulates between two membranes increasing concentration
• H+ move down their concentration gradient by diffusing through ATP synthase, converting 26 or 28 ADP to 26 or 28ATP
• H+ bonds to O2 forming H2O

Question 7

anaerobic respiration (fermentation)

Answer 7

• cytosol with no O2
• glycolysis still occurs
• then 2 pyruvate (3C) converted to 2 lactic acid (3C) in animals
• 2 ethanol (2C) and 2CO2 (1C) in plants and yeast
• 2NADH converted to 2NAD+

Question 8

advantages anaerobic

Answer 8

• even if no O2, cells still get 2 ATP from glycolysis rapidly
• NADH recycled into NAD+ for use in glycolysis
• removes pyruvate buildup which inhibits glycolysis if its levels are too high

Question 9

disadvantages anaerobic

Answer 9

• build up of lactic acid and ethanol becomes toxic

Question 10

ph/temp/enzyme conc. affect

Answer 10

same as enzymes

Question 11

O2 affect

Answer 11

affects type of cellular respiration

Question 12

glucose

Answer 12

increases rate of reaction until saturation point

Question 13

metabolism

Answer 13

increased demand for ATP means increased rate of cellular respiration

Question 14

mtDNA inheritance (endosymbiosis)

Answer 14

• only mitochondria from ova become incorporated into developing embryo (inherited from maternal line)
• mt DNA makes mitochondria organelle

Question 15

inhibitors affect

Answer 15

• cyanide (non competitive irreversible)
• ATP (non competitive reversible) if ATP levels are high