Cellular Respiration

Title :

Cellular Respiration

Author :

Kim Foglia & Kelly Reidell

Number of slides:

252

Slideshow :

Content transcript :

Cellular Respiration

Harvesting Chemical Energy

“Burn fuels” to make energy

Energy needs of life

* Animals are energy consumers

* What do we need energy for?

* synthesis (building for growth)

* reproduction

* active transport

* movement

* temperature control (making heat)

Harvesting energy stored in food

* Cellular respiration

* breaking down food to produce ATP

* in mitochondria

* using oxygen

* “aerobic” respiration

* usually digesting glucose

* but could be other sugars, 

fats, or proteins

What do we need to make energy?

* The “Furnace” for making energy

* mitochondria 

* Fuel

* food: carbohydrates, fats, proteins

* Helpers

* oxygen

* enzymes

* Product

* ATP

* Waste products

* carbon dioxide

* then used by plants

* water

Mitochondria are everywhere!!

Overview of cellular respiration

* 3 metabolic stages

* Anaerobic respiration

1. Glycolysis

* respiration without O2

* in cytosol

* Aerobic respiration

* respiration using O2

* in mitochondria

2. Krebs cycle

3. Electron transport chain

Glycolysis 

* Breaking down glucose 

* “glyco – lysis” (splitting sugar)

* ancient pathway which harvests energy

* where energy transfer first evolved

* transfer energy from organic molecules to ATP

* still is starting point for ALL cellular respiration

* but it’s inefficient 

* generate only 2 ATP for every 1 glucose

* occurs in cytosol

Glycolysis summary 

Cellular Respiration

Stage 2:

Krebs Cycle

Energy accounting of Krebs cycle 

Net gain = 2 ATP

  = 8 NADH + 2 FADH2

Cellular Respiration

Stage 3: 

Electron Transport Chain

ATP accounting so far…

* Glycolysis ? 2 ATP 

* Kreb’s cycle ? 2 ATP 

* Life takes a lot of energy to run, need to extract more energy than 4 ATP!

There is a better way!

* Electron Transport Chain 

* series of proteins built into 

inner mitochondrial membrane

* uses transport proteins & enzymes 

* transport of electrons from carriers down ETC linked to pumping of H+ 

* yields ~36 ATP from 1 glucose!

* only in presence of O2 (aerobic respiration)

Cellular respiration

A Body’s Energy Budget

What if oxygen is missing?

* No oxygen available = can’t complete aerobic respiration

* Anaerobic respiration

* also known as fermentation

* alcohol fermentation

* lactic acid fermentation

* no oxygen or 

no mitochondria (bacteria)

* can only make very little ATP

* large animals cannot survive

Anaerobic Respiration

* Fermentation

* alcohol fermentation

* yeast

* glucose ? ATP + CO2+ alcohol

* make beer, wine, bread

* lactic acid fermentation

* bacteria, animals

* glucose ? ATP + lactic acid

* bacteria make yogurt

* animals feel muscle fatigue