cellular respiration

cellular respiration

• proccess of releasing energy from food in prescence of oxygen mainly

• happens near and in mitochondria

3 Steps

1. glycolysis
2. Krebs cycle
3. Electrin Transport Chain

Cellular respiration equation

6 oxygen + glucose -> 6 carbon dioxide + 6 water + ATP

anaerobic

oxygen independent

aerobic

oxygen dependent

summary

• all 3 steps combined release 36-38 molecules of ATP per glucose
• Glycolysis produces 2 ATP
• Krebs Cycle produces 2 ATP
• Electron transpoet chain produces 32-34 ATP

Glycolysis

• first step
• occurs in cytoplasm near mitochondria
• also makes NADH and 2 ATP from NAD+ and 2 ADP
• anaerobic

Glycolysis reactants

glucose

glycolysis products

2 pyruvate
( pyruvic acid)

Krebs Cycle

• second step

• takes place in mitochondrial matrix (inner area/liquid of mitochondrial)

• aerobic

• also makes 2 ATP, 6 NADH, and 2 FADH₂

• _{also known as citric acid cycle}

Krebs Cycle reactants

• Acetyl CoA (made from pyruvate in a process in between glycolysis and Krebs Cycle)

Krebs Cycle products

• Carbon dioxide

caron dioxide

CO(2)

water

H(2)O

glucose

C(6)H(12)0(6)

oxygen

O(2)

Electron Transport chain

• third step

• takes place in inner mitochondrial membrane

• uses up the NADH and FADH₂ made in previous steps

• makes 32-34 ATP

• makes most ATP because hydrogen molecules create concentration gradient that spins ATP synthase

electron transport chain reactants

oxygen

electron transport chain products

water

Fermentation

• anaerobic

• in absence of oxygen energy still needs to be released from food

• if no oxygen available fermentation happens instead of Krebs Cycle and glycolysis

• uses up energy electrons carry so glycolysis can happen again

• makes less energy than aerobic respiration

Alcoholic Fermentation

• done by yeast
• makes alcohol
• causes bread dough to rise
• yeast runs out of oxygen, begins to ferment, and produces carbon dioxide bubbles
• uses up NADH to restore NAD+

Alcoholic Fermentation reactants

2 pyruvate

alcoholic fermentation products

• 2 alcohol
• 2 carbon dioxide

Lactic Acid Fermentation

• done by bacteria and many animals
• when done by bacteria in milk - cheese, yogurt, sour cream, etc. created
• human muscle cells also produce lactic acid
• uses up NADH to restore NAD+

lactic acid fermentation reactants

2 pyruvate

lactic acid fermentation products

2 lactate

electron donor molecules

accept and transfer high-energy electrons