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