Fermentation

Glucose

C6H12O6

Step 1: Glycolysis

• Where? In cytoplasm• What happens?

A) Glucose (from our food) is broken down

B) 2 ATP molecules released for use by the cell

C

CCATPATP

Mitochondria

En-zyme

C

CC

Step 2: Fermentation

• Two Types of Fermentation (both anaerobic):

A) Lactic Acid fermentation– Performed by animals when muscles are not receiving oxygen– Lactic acid waste created

B) Alcoholic fermentation– Performed by yeast, some plants, bacteria– Alcohol waste created

During prolonged exercise, the oxygen you inhale mainly goes to your brain. Your muscles are now lacking oxygen.

Muscle cells perform fermentation to keep you going!

How to relieve sore muscles:1) Massage2) Bananas3) Stretch after4) Hydrate

Yeast perform alcoholic fermentation to make bread. Why isn’t bread alcoholic?

Alcohol evaporates in the baking process

What’s after Glycolysis?• Glycolysis

– Creates: ATP, Glucose fragments

– Leads to either:

1) Aerobic Respiration With oxygen

present Kreb’s Cycle Electron transport

chain

2) Anaerobic Respiration Without oxygen Fermentation Allows glycolysis

to restart

O2

No O2

glyco

lysis

ferm

enta

tion ATP

ATP

Lactic Acid vs. Alcoholic Fermentation

Lactic Acid• Location: Cytoplasm• Amount of ATP created: Zero• The Point? Make molecules

to restart glycolysis• Waste: Lactic acid

Alcoholic• Location: Cytoplasm• Amount of ATP created: Zero• The Point? Make molecules

to restart glycolysis• Waste: Alcohol and CO2

glycolysis

Lactic acid fermentation

glycolysis

Alcoholic fermentation

Lactic acid

Alcohol + CO2

Glycolysis:-- In the cytoplasm-- Glucose is split into fragments-- 2 ATP created

Fermentation

Where? In the cytoplasm

What happens? Glucose fragments are

broken into either lactic acid or alcohol

Molecules to restart glycolysis created (No ATP)

Aerobic Respiration

Where? In the mitochondria

Steps? Kreb’s cycle and electron transport chain

What happens? Glucose fragments converted into 34 ATPs

With oxygen present

If oxygen is lacking

Glycolysis restarts

review

1) Name the two types of fermentation.

2) How much ATP does glycolysis create?

3) How much ATP does fermentation create?

4) Which molecule is broken down during glycolysis?

5) A buildup of which molecule causes sore muscles?

6) Which waste molecules are created by alcoholic fermentation?

7) Is fermentation aerobic or anaerobic? What does this mean?

8) Why is aerobic respiration preferred vs. fermentation?