Unit 4 Cell
PPT #2 Cellular Energy Production
Cell energy
• All nutrients that are used by
cells must be broken down to
into their monomers…let’s talk
about GLUCOSE.
• Breakdown of nutrients to
glucose is done by enzymes
Make glucose
through
Photosynthesis
Get glucose from
food
Release energy from glucose
through cellular respiration
and ATP Production
Photosynthesis-starts the ecological food webs!
WHERE: Chloroplast
WHO: plant cells
WHY: turns water and carbon
dioxide into glucose and
oxygen!
WHEN: in the presences of light
energy (sun)
Why is Photosynthesis important?
Makes organic molecules
(glucose) out of inorganic materials
(carbon dioxide and water).
It begins all food chains/webs.
Thus all life is supported by this
process.
It also makes oxygen gas!!
PHOTOSYNTHESIS
• Autotrophic Process: Plants and plant-like
organisms like some bacteria and algae make
their energy (glucose) from sunlight.
• Stored as complex carbohydrate in
their leaves, and bodies.
• 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2
BUT this reaction happens in two steps in two
different places within the cholorplast.
Photo-synthesis
means "putting together with light."
Plants use sunlight to turn water
and carbon dioxide into glucose.
Glucose is a simple of sugar.
Plants use glucose as food for
energy and as a building block
for growing.
Autotrophs make glucose and
heterotrophs are consumers of
it.
How do we know that plants make
carbohydrates from just carbon dioxide
water and light energy?
Experiments!
• For example:
Jan Baptisa van Helmont (1648) planted a
willow branch weighing 5 pounds into
200 pounds of soil and then after 4
years the tree weighed 169 lbs. and the
soil was still nearly 200 lbs.
Photosynthesis
Chemical reaction
sunlight
Carbon dioxide + water
glucose + oxygen
absorbed by chlorophyll
6CO2 + 6H2O + energy  C6H12O6 + 6O2
Plants in Action
Check it!
What is the
process
that uses
the sun’s
energy to
make
simple
sugars?
Chloroplasts are the organelle that
facilitates the 2 step Photosynthesis
process:
1. Light reaction
2. Dark Reaction
Step 1: Light Dependent Reactions
---happen in the Thylakoids of chloroplasts
--Thylakoids are flattened sacks within the chloroplasts that have
all the chlorophyll (which capture light energy)
Step 2: Light Independent Reactions
(Dark Rnx or Calvin Cycle)
--happen in the stroma of chloroplasts
--Stroma is the space within the chloroplasts
Leaves are green
because they
contain
the pigment:
chlorophyll
Leaves have a
large surface area
to absorb as much
light as possible
"Thanks for the Glucose!"
WATER SPLITTING in Thylakoids
6CO2 + 6H2O---LIGHT ENERGY---6H2 + 3O2 + 6CO2 + tiny energy
1. Light (UV radiation)is absorbed by chlorophyll in the
thylakoids
2. Light Energy splits water into H2 and O2
3. The Oxygen is “leftover” and diffuses out through stoma
(holes in underside of leaf)
4. A tiny bit of ATP (energy is created)
This Energy is used in the 2nd step (Dark Reactions)to make
Glucose
Also called: Light independent Reactions “Calvin
Cycle” in Stroma
6H2 + (tiny ATP)+ 6CO2--------C6H12O6
1. Tiny bit of energy(ATP) from splitting water is used to
split the CO2 and chemically combine it with H2 and
make into (C6H12O6).
Overall Did Photosynthesis create any extra ENERGY???
Photosynthesis produces:
NO NET ENERGY CREATED!!!...just
glucose and Oxygen
Summary of the 2 Reactions
of photosynthesis
1. Light Dependent RNX: splitting water In
chlorophyll pigment inThylakoids
• 6H2O + Light Energy-----6H2 + 3O2 + Tiny ATP
2. Light Independent RNX (Dark RNX) Calvin
Cycle
split CO2 making glucose in Stroma
• 6H2 + (tiny ATP)+ 6CO2------------C6H12O6
• Making glucose from split water and CO2 in Stroma
• No net energy produced.
Look at the
Oxygen
production
from the
Chloroplast
https://www.youtube.com
/watch?v=mYbMPwmwx8
8
The Big Picture
Photosynthesis Concept Map
• Draw your own concept map using the
chloroplasts pages.
• Write the chemical equations for the light
and dark reactions. Arrange them in a
way that tells a story about what is
happening during this process
• Add labels, arrows, and other symbols to
connect the concepts
• Write a 25 word summary of the process
of the two stages of photosynthesis
Cell Respiration
WHERE: MITOCHONDRIA
WHO: All Eukaryotic Cells
WHY: to turn sugar (glucose) into fuel (ATP)
C6H12O6+ 6 O2  6 CO2 + 6 H2O + 36 ATP
ENERGY
carbon dioxide & water are “leftovers”
Where do you think the glucose and oxygen come from????
Two Types of Cellular Respiration
Fermentation
Aerobic
• Yeast & Bacteria
• Most Eukaryotic
• When no oxygen
cells, plants,
available
animals
• only makes 2 ATP
• needs oxygen
– (ok for small things)
• makes 36 ATP
• One step:This is how we
• 3 steps
make bread, yogurt, beer
wine!
It’s a 3 STEP PROCESS
Why: to slowly release energy without heating up
the cell too much!
1. Glycolysis: Happens in the cell cytoplasm to break
down glucose
– All living things do glycolysis!!!!!!
– Glyco (sugar) Lysis (break apart)
– C6H12O6 broken into 2, 3 Carbon compounds(pyruvate)
– C6H12O6
2 C3H6O3 + 2 ATP
– Without oxygen, breaking glucose gives 2 ATP.
2. Krebs Cycle: In the mitochondria, makes 2 ATP (not
efficient)
The 2, 3 Carbon compounds(pyruvate) mix with
Oxygen to create 2 ATP and a LOT of ELECTRONS. e3. Electron Transport Chain In the mitochondria
membranes, electrons go back and forth across the
membranes and this creates 36 ATP!!!! And releases
CO2 and H2O….ready to start all over again!
Cellular Respiration Summary:
• 1. Glucose is broken into pyruvate in the cell
cytoplasm giving off +2 ATP
glycolysis
•
Organisms with no Oxygen can still generate energy this way.
• 2. Pyruvate in the mitochondria undergo reactions with
Oxygen and produce +2 ATP and lots of e-
Kreb Cycle
• 3. Electrons e- go back and forth between the mitochondria
membrane generating +36 ATP + CO2 and H20 as products.
»
Electron Transport Chain
Cellular Respiration Concept Map
• Using the mitochondria picture:
• Write the overall reaction for cellular respiration.
• Write the reactions for the 3 steps of cellular
respiration in a way that tells a story about what is
happening during these reactions
• Add labels, arrows, and other symbols to connect the
concepts
• Write a 25 word summary of the process of cellular
respiration
• Use arrows or color coding to show how the cycles
are relayed… (hint: look at the equation)
• The main energy molecule in organisms
• Energy is held in the Chemical Bonds
– Breaking a bond releases energy
• ATPADP
– Making a bond stores energy
• ADP ATP
Cellular Energy in the form of ATP gets used
to drive cell processes
EX: Cell Division
Cell Transport
The Big Picture
1.
Plants make glycose through
Photosynthesis. People eat food
to be broken into glucose.
2. All nutrients must be broken down
to Glucose
3. Glucose must be converted to ATP
as energy through cell respiration.