Cellular Respiration

Remember this: Aerobic

Process that requires oxygen in order to take place Anaerobic

Process that requires NO oxygen to take place. Glycolysis

Process that splits glucose (6 carbon) into two 3 carbon molecules and makes 2 ATP. (this must take place before respiration can occur)

Cell Respiration Chemical energy is released when sugar is

broken down to make ATP and oxygen is present.

This process is almost a mirror image of photosynthesis.

This process also has 2 stages. All this takes place in the mitochondria.

Stage 1 Known as the Krebs Cycle This is going to produce energy molecules

that are used in the 2nd part of cell respiration.1. The 3-carbon molecules from glycolysis are

broken down.2. Small amount of ATP is made (for stage 2)3. Carbon dioxide is given off as a byproduct

Stage 2 Known as the Electron Transport Chain1. Energy is transferred to here from Krebs

Cycle.2. Oxygen is taken in.3. Lots of ATP are made.4. Water and heat are given off as byproducts.

Fermentation

Chapter 4.6

Glycolysis This is where cells break apart 6 carbon

sugars into 3 carbon sugars and makes 2 ATP.

This does NOT require oxygen Anaerobic

This usually stops when oxygen appears.

Fermentation allows this to continue so it can make energy for the cells to use.

Fermentation Normally you maintain oxygen levels, but

when you do hard work, your body can’t keep up the oxygen levels.

This means you need a different energy source so you can still function.

We use fermentation to continue glycolysis for energy.

Fermentation Comes in two different forms:

Lactic Acid Fermentation Alcohol Fermentation

Both forms use NADPH as it’s energy source.

Remember: both of these are Anaerobic – They don’t need oxygen to work.

Lactic Acid Fermentation

Lactic Acid Fermentation1. Glycolysis makes ATP (used for energy

elsewhere) and NADPH2. Pyruvates (3 carbon molecules) are formed3. Energy is added and Pyruvates become

Lactic Acid.

This important byproduct is why your muscles hurt after you work them out.

Alcohol Fermentation

Alcohol Fermentation1. Glycolysis makes ATP (used for energy

elsewhere) and NADPH2. Pyruvates (3 carbon molecules) are formed3. The pyruvates are broken apart and CO2

breaks off. 2 carbon molecule left behind.4. 2 Carbon molecule is alcohol.

This is why breads become “fluffy” with time.

Uses Remember: Fermentation doesn’t make

energy, glycolysis does. Fermentation just lets this continue.

Lactic acid fermentation – used for your muscles.

Alcohol fermentation – used for making breads, cheeses, digestive bacteria.