Chemical Energy for Cells

Chemical energy for cells comes in 2 forms:•ATP= Adenosine Triphosphate (high energy)•ADP= Adenosine Diphosphate (lower energy)

triphosphateadenosine

adenosine diphosphate

tri=3

di=2

Different foods provide different amounts of ATP:• Fats store the most energy.• about 146 ATP from a triglyceride

• Carbohydrates are the molecules most commonly broken down to make ATP. • Up to 36 ATP from one glucose molecule

• Proteins are least likely to be broken down to make ATP, but have about the same amount of energy as a carbohydrate.

Chemical Energy in Plants

• Plants are producers because they produce their own chemical energy through photosynthesis.

• Photosynthesis is a process that captures sunlight to make sugars (=carbs) for chemical energy.

• Photosynthesis happens in the chloroplast organelle (in leaf cells).

Photosynthesis takes place in two parts of chloroplasts.

chloroplast

stroma

grana (thylakoids)• grana/granum (pl.)

(made up of thylakoids *containing chlorophyll)

• stroma(fluid outside grana)

thylakoid

Photosynthesis Equation:6CO2 + 6H2O + sunlight C6H12O6 + 6O2

Sugar (glucose)

2 parts of Photosynthesis:• Light-Dependent reactions take place in/across thylakoid.(Sunlight and water are used to produce ATP and give off oxygen)

• Light-Independent reactions take place in the stroma. (AKA: Calvin Cycle)(ATP and carbon dioxide are used to produce sugars)

C6H12O6

grana (stack of thylakoids)

thylakoid

sunlight

1 six-carbon sugar

6H2O

6CO2

6O2

chloroplastchloroplast

1

2

43

energy

stroma (fluid outside the thylakoids)

Respiration• Cellular Respiration is the opposite of

photosynthesis:C6H12O6 + 6O2 6CO2 + 6H2O + ATP(energy)

* This is an aerobic process- it NEEDS oxygen

• 3 major steps:1) Glycolysis: NOT in mitochondria (in cytoplasm

of cell) =anaerobic process to make ATP

In mitochondria:2) Krebs cycle (in matrix): makes small amount

of ATP, releases carbon dioxide3) Electron transport (in inner membranes):

makes ATP and releases water

6H O2

6CO 2

6O 2

mitochondrionmitochondrion

matrix (area enclosedby inner membrane)

inner membrane

ATP

ATP

energy

energy from glycolysis

1

2

4

3

and

and

and