Cellular Respiration

Question 1

Why does a cell require energy?

Answer 1

For mechanical work (motor proteins), to make new materials (growth and repair), transport (across membranes), maintain order

Question 2

What is the respiration equation?

Answer 2

C6H12O6 + 6O2 ———> 6CO2 + 6H2O + Energy (ATP)

Question 3

What is mitochondria?

Answer 3

An organelle that contains mitochondrial DNA and ribosomes. 1-10um long , 1-1000s per cell
Has two membranes (inner and outer). Inner contains mitochondrial matrix & is highly folded

Question 4

What are the three stages involved in cellular respiration?

Answer 4

1. Glycosis
2. Pyruvate Oxidation and Citric Acid Cycle
3. Oxidative Phosphorylation

Question 5

What happens in glycosis (stage one of respiration)?

Answer 5

Occurs in cytosol
Sugar converted into smaller molecule pyruvate
Generates 2ATP
Transfers electrons to NAD+ making NADH

Question 6

What happens in pyruvate oxidation and citric acid cycle (stage two of respiration)?

Answer 6

Occurs in the mitochondrial matrix
Pyruvate converted into Acetyl CoA
Acetyl CoA enters citric acid cycle
Output is ATP, NADH & FADH2

Question 7

What happens in oxidative phosphorylation (stage three of respiration)?

Answer 7

NADH and FADH2 shuttle e- into inner mitochondrial membrane, e- move through protein complex, protons (H+) are pumped across membrane which accumulate in intermembrane space, proton concentration different on either side of membrane, ATP synthase complex spans from intermembrane to mitochondrial matrix and proton gradient powers ATP synthesis. ATP synthase converts ADP + Pi —> ATP

Question 8

What is ATP?

Answer 8

Adenosine Triphosphate - enables controlled release of energy
The cell continuously uses and regenerates ATP