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
ATP gives off energy when a phosphate group is
removed and it becomes ADP
phosphate removed
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
1.
2
chloroplast
4. thylakoid
Contains: chlorophyll
3. 6H2O
5. 6O2
6. Energy carrying molecules are being transferred
light independent reactions
7. 6CO2 from the atmosphere
stroma (fluid outside the thylakoids)
8. Light independent
reaction
1 six-carbon sugar
9
C6H12O6
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
Carbon dioxide plus water plus light
 (reactants)
(products)
C6H12O6 + 6O2
yields
Glucose and oxygen
Cellular Respiration
& Fermentation
4.4, & 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)
Glycolysis: Anaerobic
1 cytoplasm
process in
that splits glucose
matrix (area enclosed
into two 3C molecules by inner membrane)
Makes 2 ATP
1. mitochondrion
3. Kreb’s Cycle
Takes place in: matrix of
mitochondria; produces 2 ATP
ATP
2. 2 Pyruvates
ATP
and
4. 6CO2
5. Energy transferred to
2nd stage (aerobic stage)
inner membrane
6. ETC: energy from
glycolysis and 6O2 enter
ATP
7. 64 H2O produced
and a large amount
of ATP (32)
 Anaerobic
Glycolysis
 Takes 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)
 Aerobic
 Takes place in matrix of mitochondria (only
in eukaryotes)
 2 pyruvate (made during glycolysis) enter the
mitochondrion
 2 ATPs are made
Electron Transport Chain
(ETC)
 Aerobic
 Takes place in inner membrane of mitochondria (cristae)
 Oxygen is taken in and combines with hydrogens to
release water
 32 ATP are made
ATP from Cellular
Respiration
 4 from Glycolysis (uses up 2, so really only gain 2 ATP)
 2 ATP from Kreb’s cycle
 32 ATP from ETC
 GAIN 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 Fermentation
 Alcoholic Fermentation