Cellular Respiration (UPDATED) - YouTube

What is the main purpose of cellular respiration?

To break down glucose in the presence of oxygen to produce ATP, which powers cellular processes.

What is the overall chemical equation for aerobic cellular respiration?

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$$

What molecule is known as the primary energy currency of the cell?

ATP (Adenosine Triphosphate)

What are the three main stages of aerobic cellular respiration?

Glycolysis, the Krebs cycle (citric acid cycle), and the electron transport chain.

Where in the cell does glycolysis take place?

In the cytoplasm (cytosol).

Is glycolysis an aerobic or anaerobic process?

Anaerobic process, because it does not require oxygen.

What molecule enters glycolysis, and what primary organic molecules are produced?

One glucose molecule ($C_6H_{12}O_6$) enters glycolysis and is broken down into $2$ molecules of pyruvate.

What is the net ATP yield produced directly by glycolysis per glucose molecule?

$2\,\text{ATP}$ molecules

What is the primary function of $NAD^+$ and $FAD$ in cellular respiration?

They act as electron carriers that accept electrons and hydrogen to become $NADH$ and $FADH_2$.

Where does the Krebs cycle occur within eukaryotic cells?

In the mitochondrial matrix.

Which waste gas is produced during the oxidation of pyruvate and the Krebs cycle?

Carbon dioxide ($CO_2$)

How many turns of the Krebs cycle are required per glucose molecule?

$2$ turns (one turn for each of the $2$ pyruvate molecules).

Which electron carriers generated in the Krebs cycle supply electrons to the electron transport chain?

$NADH$ and $FADH_2$

Where is the electron transport chain located in mitochondria?

In the inner mitochondrial membrane (cristae).

What is the final electron acceptor in the electron transport chain during aerobic respiration?

Oxygen ($O_2$)

What byproduct is formed when oxygen accepts electrons and protons at the end of the electron transport chain?

Water ($H_2O$)

Which enzyme synthesizes ATP as hydrogen ions flow across the inner mitochondrial membrane?

ATP synthase

Which stage of cellular respiration produces the highest amount of ATP?

The electron transport chain (oxidative phosphorylation).

What is the total approximate net yield of ATP produced per glucose molecule in aerobic cellular respiration?

Approximately $30$ to $38\,\text{ATP}$ molecules.

What pathway do cells use to process pyruvate when oxygen is unavailable?

Fermentation (anaerobic respiration).

What is the primary purpose of fermentation in anaerobic conditions?

To regenerate $NAD^+$ from $NADH$ so that glycolysis can continue producing ATP.

What type of fermentation occurs in human muscle cells during strenuous exercise?

Lactic acid fermentation

What are the key end products of alcoholic fermentation in yeast?

Ethanol, carbon dioxide ($CO_2$), and regenerated $NAD^+$

What causes bread dough to rise when yeast undergoes fermentation?

The release of carbon dioxide ($CO_2$) gas bubbles trapped in the dough.

What end product accumulates during lactic acid fermentation?

Lactic acid (lactate)