Cellular Respiration

Question 1

What is Cellular Respiration?

Answer 1

• Series of metabolic reactions converting food energy into a usable form - ATP

Question 2

What is ATP?

Answer 2

• Adenosine Tri Phosphate
• ATP is unstable
• Cells make ATP all the time

Question 3

Read

Answer 3

• In cells, glucose is oxidized through a long series of carefully controlled reactions, during these process energy is released.
• The released free energy is used to synthesize ATP (by adding phosphate group to ADP to make ATP)
• Cells generally contain enough ATP to sustain from 30 secs to a few mins of activity

Question 4

How is ATP regenerated? (see slide 5)

Answer 4

• energy to phosphorylate ADP comes
  from catabolic reactions in the cell.
• Cellular respiration regenerate ATP when used
  in the cell.

Question 5

What is Catabolism?

Answer 5

• The breakdown of molecules.

- Stored chemical energy to produce ATP.

Question 6

What is Anabolism?

Answer 6

• The synthesis of larger molecules from smaller components.

- Uses energy to form ATP.

Question 7

How do cells make ATP?

Answer 7

• By obtaining glucose to make ATP

- ATP comes from glycolysis ONLY.

Question 8

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Answer 8

• Plants produce glucose during photosynthesis.

- Other organisms obtain glucose from food.

Question 9

What do organisms store excess glucose?

Answer 9

• Glycogen

- Starch

Question 10

What is breathing?

Answer 10

• Inhalation of oxygen into lungs to be delivered to cells

- Exhalation of carbon dioxide.

Question 11

What is cellular respiration?

Answer 11

• Needs oxygen from breathing as part of the metabolic process; carbon dioxide waste is returned to the lungs.

Question 12

What is Aerobic Cellular Respiration?

Answer 12

• Occurs mainly in the mitochondria.
• Needs Oxygen.
• Glucose (C6H12O6) + 6O2 → 6H2O + 6CO2 + Energy

Question 13

What are the stages in cellular respiration?

Answer 13

• Stage 1: Glycolysis
• Stage 2: Citric Acid (Krebs Cycle)
• Stage 3: Electronic transport chain and ATP synthesis.

Question 14

What happens in stage 1 : Glycolysis?

Answer 14

• Occurs in the cytosol/cytoplasm
• Doesn’t require Oxygen
• 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules.
• Produces 2 ATP.

Question 15

What happens in the Citric acid cycle (Krebs cycle)

Answer 15

• The Pyruvic acid loses a carbon dioxide (decarboxylated).
• The now 2-carbon molecule enters Citric acid cycle, 2-carbon fragment is metabolized inside mitochondrion
• The Citric acid cycle completes the oxidation of glucose.
• Series of enzyme-catalyzed reactions in the mitochondrial matrix.
• Produces 2 ATP
• Releases CO2 + NADH

Question 16

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Answer 16

• Most of glucose’s original energy is contained in the electrons transferred to NADH and FADH2.
• The electrons (and protons) are
  ultimately transferred to oxygen to form water.

Question 17

Nicotinamide adenine dinucleotide.

Answer 17

: NAD+ - Empty Taxicab for electron

• The empty taxicab (NAD+) picks up electrons + hydrogen ions (H+).
• Then becomes a full taxicab (NADH) that carries electrons to their final destinations.

Question 18

What is The Electron Transport Chain?

Answer 18

• Series of proteins in the mitochondrion acting like a

conveyor belt for electrons.

Question 19

What happens in The Electron Transport Chain and ATP Synthesis?

Answer 19

• Proteins oxidize NADH and FADH2 (where all
  electrons come from)
• NADH drops off electrons and H+ ions.
• Electrons move through the chain.
• H+ conc increases as the ions are moved into the
  intermembrane space.
• Electrons from NADH and FADH2 are passed from one protein to the next, releasing energy for ATP synthesis.
• ( read) As the electrons travel through the chain, they go from a higher to a lower energy level. Energy is released in these “downhill” electron transfers, and several of the
  protein complexes use the released energy to pump protons (H+) from the mitochondrial matrix to the intermembrane space.

Question 20

What is the non-protein used for oxidation in the Electron Transport Chain?

Answer 20

• Ubiquinone or coenzyme Q

Question 21

Where does glycolysis occur and what does it produce?

Answer 21

• Cytoplasm

- 2 pyruvate, 2 ATP, 2 NADH

Question 22

Where does The citric acid cycle occur and what does it produce for both 1 + 2?

Answer 22

Cycle 1

• Mitochondrial matrix
• 2 Acetyl CoA, 2 NADH, 2 CO2

           Cycle 2

• Mitochondrial matrix
• 4 CO2, 6 NADH, 2 FADH2, 2 ATP

Question 23

Where does The electron transport chain occur and what does it produce?

Answer 23

• Mitochondria; inner membrane

- 30-34 AT, 6 H2O

Question 24

What happens when carbs aren’t available for ATP production?

Answer 24

• For ATP production, cells first use carbohydrates → then fats → and finally proteins.

Question 25

What does Anaerobic respiration not require?

Answer 25

• Oxygen

Question 26

What happens to the muscles during exercise?

Answer 26

• Muscles run low on Oxygen.
• NAD+ levels decrease.
• Muscle cells use fermentation to REGENERATE NAD+.

Question 27

Where does Lactic Acid come from?

Answer 27

• Builds up due to fermentation in muscle cells.

Question 28

Where is lactic acid transported to?

Answer 28

• Back to the liver for conversion to pyruvic acid.

- Oxygen debt needs to be restored for conversion.

Question 29

Fermentation Examples?

Answer 29

• Yogurt
• Sour cream
• Cheese
• Microbes transform milk sugars into lactic acid.
• Yeast cells convert glucose to ethyl alcohol (ethanol).

Question 30

Aerobic Respiration Equation?

Answer 30

• Glucose (C6H12O6) + 6O2 → 6H2O + 6CO2 + Energy

- Glycolysis + Krebs cycle + ETC = 30 - 34 ATP

Question 31

Anaerobic respiration/ Fermentation?

Answer 31

• Glucose (C6H12O6) Lactic Acid

- Glucose (C6H12O6) Ethanol + CO2