ATP, Photosynthesis, and Cellular Respiration

Chapter 4 Sections 4.1, 4.2, and 4.3

4.1 How do living things get ATP?

ATP is the energy carrier in living things.

ATP stands for Adenosine triphosphate.Living things get ATP from breaking down

carbon based molecules. (carbohydrates & lipids)Starch molecule

Glucose molecule

This is how it works

phosphate removed

ATP gives off energy when a phosphate group is removed and it becomes ADP

4.2 & 4.3 Photosynthesis

The process of photosynthesis captures energy from sunlight and converts it into sugar.

This process happens in organisms called autotrophs or producers. (Need to make their own food)

This process takes place in and organelle called the chloroplast.

The chloroplast has a green pigment in it called chlorophyll that is responsible for capturing the light energy.

Let’s label the inside of a chloroplast

C6H12O6

Contains: chlorophyll

4. thylakoidsunlight

1 six-carbon sugar

3. 6H2O

7. 6CO2 from the atmosphere

5. 6O2

chloroplast2

9

6. Energy carrying molecules are being transferred to light independent reactions

stroma (fluid outside the thylakoids)

8. Light independent reaction

1.

So how does photosynthesis work?

The first stage of photosynthesis is called the Light Dependent Stage.

Light and water are used to produce ATP and oxygen is released

Occurs on the thylakoid membranes inside chloroplasts

So how does photosynthesis work?

The second stage of photosynthesis is called the Light Independent Stage/ Calvin Cycle/ Dark Cycle.

This process takes place in the stroma.Carbon dioxide (CO2) is added from the

atmosphere to help in chemical reactions to produce glucose (C6H12O6)

The chemical formula for photosynthesis

6CO2 + 6H2O + light C6H12O6 + 6O2

(reactants) (products)

Carbon dioxide plus water plus light

yields Glucose and oxygen

Cellular Respiration & Fermentation4.4, & 4.6

4.4 & 4.6 – Overview of Cellular Respiration & Fermentation

Key Concept:The overall process of cellular

respiration converts sugar into ATP using oxygen.

Cellular respiration is an aerobic process with two main stages.

Purpose of Cellular Respiration

To make ATP from the energy stored in glucose

Remember: the purpose of photosynthesis was just to get glucose

Cellular Respiration has 2 parts

Anaerobic (does not require oxygen)Glycolysis

Aerobic (requires oxygen)Kreb’s Cycle (Citric acid Cycle)Electron Transport Chain (ETC)

4. 6CO2

6. ETC: energy from glycolysis and 6O2 enter

1. mitochondrion

matrix (area enclosedby inner membrane)

inner membrane

ATP

ATP

5. Energy transferred to 2nd stage (aerobic stage)ATP

1

4

and

Glycolysis: Anaerobic process in cytoplasm that splits glucoseinto two 3C moleculesMakes 2 ATP

3. Kreb’s CycleTakes place in: matrix of mitochondria; produces 2 ATP

2. 2 Pyruvates

7. 6 H2O produced and a large amount of ATP (32)

Glycolysis AnaerobicTakes place in cytoplasm (eukaryotes and

prokaryotes do this step since all cells have cytoplasm)

Splits one glucose molecule into two pyruvate molecules

2 ATPs are gained

Kreb’s Cycle (Citric Acid Cycle)

AerobicTakes place in matrix of mitochondria (only

in eukaryotes)2 pyruvate (made during glycolysis) enter the

mitochondrion2 ATPs are made

Electron Transport Chain (ETC)

AerobicTakes place in inner membrane of mitochondria

(cristae)Oxygen is taken in and combines with hydrogens to

release water32 ATP are made

ATP from Cellular Respiration

4 from Glycolysis (uses up 2, so really only gain 2 ATP)

2 ATP from Kreb’s cycle32 ATP from ETCGAIN 36 ATP from one glucose molecule

Equation for Cellular Respiration

C6H12O6 + 6O2 6CO2 + 6H2O + 36ATP

Like the reverse of photosynthesis

What happens when there’s no/not enough oxygen or

there are no mitochondria?Answer: Fermentation

Two Kinds:Lactic Acid FermentationAlcoholic Fermentation