HETEROTROPHY- A LOOK INTO CELLULAR RESPIRATION

All organisms need a source of energy

and a source of Carbon!

WHAT IS A HETEROTROPH?

An organism that needs to CONSUME something for

food/energy

WHAT SUBSTANCE IS REQUIRED FOR CELLULAR RESPIRATION TO OCCUR?

Glucose

WHERE DOES GLUCOSE COME FROM?

Photosynthesis

SOOOO…In order for a heterotroph to obtain energy, plants must undergo photosynthesis,

producing glucose for use in cellular respiration.

Let’s Look at the Big Picture

CELLULAR RESPIRATION PRODUCES ATP. WHAT MOLECULE DO YOU THINK IS NEEDED

FOR CELLULAR RESPIRATION TO OCCUR?

Ummmm…Oxygen?

But WAIT! What if there’s no oxygen present???

Hello. My name is

Saccharomyces cerevisae!

My friends call me Yeast

ANAEROBIC CELLULAR RESPIRATION.

NO Oxygen is present!

STEP 1: GLYCOLYSIS- OCCURS IN THE CYTOPLASM OF THE

CELLGlyco = sugarLysis = split

Glycolysis =The splitting of Glucose

Glycolysis Animation

Let’s look at that again!

STEP 2: FERMENTATION

ONLY occurs if Oxygen is not present, causing the pyruvates to

stay in the cytoplasm and ferment, or rearranges it into…

LACTIC ACID

That’s me!

And me!

And me!

LACTIC ACID

OR ETHYL ALCOHOL AND CO2

Hola! It’s me again…

THIS IS CALL ANAEROBIC CELLULAR RESPIRATION, OR JUST

FERMENTATION, FOR SHORT.

Got it? Let’s see what this looks like!

Aq uila c hrysa e to s

I love Oxygen.

BUT WHAT IF OXYGEN IS PRESENT???

Whoo hoo! We get to practice AEROBIC

Cellular Respiration!

…which is WAY more efficient!...Let’s learn more !!!

STEP 1: GLYCOLYSISRemember?

The function of the Krebs Cycle- to further the breakdown of the products of glycolysis-

releasing CO2 and creating ATP. NAD+ and

FAD+ are reduced to create NADH and

FADH2, these molecules are used during the

next stage…

http://www.bio.miami.edu/~cmallery/150/makeatp/pyraerobic.jpg

Step 2: The pyruvates enter the mitochondrial matrix,

and participate in the Krebs Cycle

Step 3: The Electron Transport System (a.k.a. Oxidative Phosphorylation)

Oxidative Phosphorylation occurs on the inner mitochondrial membrane

NADH and FADH2 (from the Krebs Cycle) are oxidized, releasing H+ that are pumped across the membrane and create ATP…and LOTS of it!

Let’s see what that looks like!