Chapter 9- Cellular Respiration Flashcards
Where do organisms get the energy they need for life processes?
Food
What is a calorie?
A Calorie?
calorie- amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius
Calorie- a kilocalorie: 1000 calories
Carbohydrates and proteins contain how much energy per gram? What is the energy content of fats? Why do foods differ in the amount of energy they contain?
a.
Carbs and proteins- 4000 calories (4 Calories)
b.
Fats- 9000 calories (9 Calories)
c.It is dependent upon the composition of the food. Some foods have more carbohydrates than others, etc.
Define cellular respiration.
Cellular Respiration- The process that releases energy from food in the presence of oxygen.
What are the 3 stages of cellular respiration and where in the cell does each stage occur?
a.
Glycolysis- cytoplasm
b.
Krebs Cycle- matrix
c.Electron Transport Chain- Inner mitochondrial membrane
Compare photosynthesis and cellular respiration
Photosynthesis Function: energy capture Location: chloroplasts Reactants: CO2, H2O, light Products: oxygen, glucose
Cellular Respiration energy release cytoplasm & mitochondria glucose and oxygen CO2, H2O, energy
Energy flows in opposite directions
Equations are reverse of each other
Write the equation for cellular respiration in both words and symbols
Symbols: 6O2 + C6H12O6 → 6CO2+6H2O+Energy
Words: Oxygen + Glucose → Carbon dioxide+Water+Energy
What is the difference between “aerobic” and “anaerobic”? Identify each stage of cellular respiration as either aerobic or anaerobic.
Aerobic- oxygen is present
Krebs Cycle
ETC
Anaerobic- no oxygen present
Glycolysis
Describe what happens during glycolysis
1 molecule of glucose (6 carbon compound) is transformed into 2 molecules of pyruvic acid (3 carbon compound)
Where does glycolysis occur in the cell?
Cytoplasm
How many ATP’s are used to jumpstart glycolysis?
2 ATP
To which electron carrier are high-energy electrons passed during glycolysis?
NAD+
What is the net energy gain in glycolysis?
2 ATP
Where do products of glycolysis go?
2 NADH goes to ETC
4 ATP
-2 go back through glycolysis
2 Pyruvic Acid goes to Krebs Cycle
Where in the cell does the Krebs Cycle occur?
Matrix
What happens during the Krebs Cycle?
Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.
Is the Krebs cycle aerobic or anaerobic?
aerobic
What product of glycolysis is used to start the Krebs Cycle?
2 pyruvic acid
Into what 2 products is pyruvate broken down into in the Krebs cycle?
NADH and FADH+
Acetyl-CoA combines with what 4-carbon compound in the Krebs cycle?
Succinate
Name 4 products of the Krebs cycle.
NADH
FADH2
ATP
CO2
How does the ETC use the high-energy electrons from glycolysis and the Krebs cycle?
To convert ADP to ATP
As electrons pass through the ETC, a gradient of H+ ions build up where in the mitochondria?
Intermembrane space
How does the cell use the charge differences that build up across the inner mitochondrial membrane during cellular respiration?
Chemiosmosis- The charge differences forces H+ ions through channels in the enzymes, causing the ATP synthases to spin. The enzymes grab an ADP molecule and attaches a phosphate group, producing ATP.
How many molecules of ATP are produced in the entire breakdown of glucose?
36 ATP molecules
What is fermentation? Name 2 types of this process discussed in class.
A process that makes it possible to continue to produce ATP after glycolysis if oxygen is not available.
Alcoholic Fermentation
Lactic Acid Fermentation
Which form of fermentation is carried out by your body?
Lactic Acid Fermentation
Is fermentation aerobic or anaerobic?
anaerobic
What are 3 main sources of ATP available for human muscle cells?
ATP already in muscles
ATP made by lactic acid fermentation
ATP produced by cellular respiration
During a race, how do your muscle cells produce ATP after the store of ATP in muscles is used?
It then uses ATP made by lactic acid fermentation which is usually enough energy to last 90 seconds.
Why does a sprinter have an oxygen debt to repay after the race is over?
The only way to get rid of lactic acid is in a chemical pathway that requires extra oxygen.
A runner needs more energy for a longer race. How does the body generate the necessary ATP?
It uses ATP made in cellular respiration
Why are aerobic forms of exercise so beneficial for weight control?
The stores of glycogen are usually enough to last about 15 to 20 minutes- after that the body begins to break down other stored molecules (including fats) for energy.
