Cellular Respiration The process by which mitochondria break

Cellular Respiration The process by which mitochondria break down glucose to make ATP Two types • Aerobic respiration: requires oxygen and carried out by plants, animals, and some bacteria • Anaerobic respiration: requires no oxygen and carried out by yeast, some bacteria, and sometimes animals Chemical equation for aerobic respiration C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + ATP glucose + oxygen carbon dioxide + water + ATP

Some of aerobic respiration occurs in the mitochondria (plural of mitochondrion) • Makes energy for the cell through aerobic respiration Structure of Mitochondrion Inner membrane Outer membrane Cristae – fold in inner membrane Krebs cycle takes place in the space between inner and outer membranes Electron Transport Chain takes place in the folds of the inner membrane

Step 1: Glycolysis – Occurs in the cytoplasm ATP Enzymes Glucose 6 carbon sugar Pyruvate Pyruvic Acid = 3 carbons e- e. NADH Glucose breaks down into 2 pyruvate (2 ATP are also made)

Intermediate step: Pyruvate becomes acetyl Co. A Pyruvate loses 1 (Occurs in the cytoplasm) Pyruvate Acetyl Co. A carbon and 2 carbons are left – the 2 carbons are given the name ACETYL Co. A is attached to ACETYL Step 2: Citric Acid Cycle (Krebs Cycle) – Occurs in the mitochondria ATP Acetyl Co. A Citric Acid Cycle ATP Citric acid e- e e e- - -NADH

Step 3: Electron Transport Chain – Occurs in the mitochondria ee- e- NADH Electron transport chain Made in Step 2 32 e- Electrons move down the electron transport chain (series of proteins that pass the electrons along). Electrons are caught by oxygen to make water. 32 ATP are made. Oxygen we breathe Water ATP

ATP Totals for Aerobic Respiration Glycolysis 2 ATP Citric Acid Cycle 2 ATP Electron Transport Chain 32 ATP Total for 1 glucose molecule 36 ATP

Photosynthesis and respiration are the opposite of each other Photosynthesis Plants * use sunlight to make glucose * take in carbon dioxide * give off oxygen *carbon dioxide + water + sunlight glucose + oxygen Respiration Animals and plants * eat plants to get glucose * take in oxygen * give off carbon dioxide *glucose + oxygen carbon dioxide + water + ATP

Anaerobic respiration (requires no oxygen) Also called fermentation 2 types: alcoholic fermentation and lactic acid fermentation Both begin with glycolysis o. No citric acid cycle or electron transport chain Alcoholic fermentation Pyruvate ethyl alcohol + carbon dioxide Carried out by yeast and some bacteria Used in brewing beer, making wine, and baking bread and cakes Only 2 ATP are made in anaerobic respiration so it is not as good as aerobic respiration (36 ATP) Lactic acid fermentation Pyruvate lactic acid Carried out by your muscles when you’re exercising hard (need ATP) and can’t get oxygen into you fast enough (can’t do aerobic respiration) Causes muscle cramps and soreness

ATP Enzymes Glucose Pyruvate 1. Name this process. 2. Where does it take place? 3. How many carbons are in each pyruvate molecule? ATP

ATP Acetyl Co. A ATP Citric acid e- e e e- - -NADH 4. Where does this step take place in the cell? 5. Where did Acetyl Co. A come from? How many carbons does it contain?