4.6 Respiration Steps Aerobic and Anaerobic

What is the difference between cellular respiration and breathing?

What is the difference between cellular respiration and breathing? Breathing is using your respiratory tract to pull air into your lungs and push air out of your lungs. Cellular respiration is using the oxygen in the air to burn glucose and recharge ATP inside all of your cells.

What is the overall goal of respiration?

What is the overall goal of respiration? C6H12O6 + 6H2O  6CO2 + 6H2O +E to recharge 36 ADP to ATP Makes 36 ATP: a lot potential chemical energy for any cell reaction. Collect H• to run ATP synthase.

Step 1 Glycolysis in Cytoplasm Glucose + 2ADP + 2Pi  2 Pyruvic Acid + 2ATP and NAD  NADH (start collecting H)

Another Diagram Version:

Know the Areas: Crista Membrane and Matrix

Step 2: Pyruvic Acid enters the Mitochondrion’s Matrix Goes from 3 C to a 2 C molecule, giving off CO2 (2 C molecule is called Acetyl Coenzyme A)

Step 3: Krebs Cycle The 2 carbon pieces of glucose (Acetyl Coenzyme A) enter the Krebs Cycle. During the Krebs Cycle, electrons and hydrogen atoms are collected by the NAD and FAD carrier molecules. The left over parts make up CO2 which diffuses out of the mitochondria and out of the cell, it is ultimately exhaled.

Step 4: Electron Transport Chain The Hydrogen ions carried by NAD and FAD are released so they can be pumped out into the intermembrane space Electrons carried by NAD and FAD run the hydrogen ion pumps. To keep the circuit going, oxygen picks up the hydrogens and electrons to make water. Water is exhaled.

Step 5: Make ATP H+ can run down its concentration gradient through the ATP synthase membrane protein, ADP + Pi  ATP Lots of ATP now accumulates inside the matrix of the mitochondria.

Step 6: ATP leaves the Mitochondrion It is pumped out through a membrane protein. It is free to supply energy for any cell process.

Mitochondrion vs. Chloroplast?

Mitochondrion vs Chloroplast

Big Ideas: Aerobic/Cellular Respiration Harnessing glucose energy – don’t let it burn all at once. The energy you are using and giving off as heat is the same energy that hit the earth from the sun some days ago: v E  ATPGLUATP  heat/work E

Fermentation or Anaerobic Respiration What if you need ATP but cannot get enough oxygen? Done without oxygen, done without mitochondria. Use the first glycolysis step in the cell cytoplasm and just get 2 ATP 2 Kinds: Lactic Acid and Alcoholic Fermentation

Lactic Acid Fermentation Step 1: Glycolysis (muscles and bacteria) Glucose + 2ADP + 2Pi  2 Pyruvic Acid + 2ATP and NAD  NADH (start collecting H•)

Lactic Acid Fermentation Step 2: Make Pyruvate into Lactic acid To capture H and electrons from NAD Starts over again Bypass mitochondria Pro: Fast source of ATP Con: Yields 2 ATP, not 36. Con: Acid buildup hurts.

Ethyl Alcohol Fermentation Step 1: Glycolysis (yeast) Glucose + 2ADP + 2Pi 2 Pyruvic Acid +2ATP +CO2 and NAD  NADH (start collecting H•)

Ethyl Alcohol Fermentation Step 2: Make Pyruvate into Ethyl Alcohol To capture H and electrons from NAD Starts over again Bypass mitochondria Pro: Fast source of ATP Yeast prefer this to aerobic respiration

Uses for Fermentation: Lactic Acid Fermentation: Bacteria ferment milk to create yogurt, now marketed as “probiotics.” (Lactobacillus species) Ethyl Alcohol Fermentation: Yeast for baking, brewing, ethyl alcohol fuel production, genetics studies. (Saccharomyces species) Soy sauce uses both types of fermentation