Do Now
• What is energy?
• How do we get energy?
• Do all organisms get energy the same
way as we do?
Objectives
• Explain how different organisms obtain energy
• List the starting materials, process, and
products for both photosynthesis and
respiration.
• Determine what happens when oxygen is not
available for cellular respiration.
Photosynthesis Video!
• https://www.youtube.com/watch?v=e
o5XndJaz-Y
2.2- “Cells Capture and Release
ENERGY!!
• 1. All cells need energy for the many
functions that they carry out!
Types of Energy
I.
Chemical Energy- stored in bonds between
atoms of molecules.
–
–
released when bonds break
Glucose= most common form, creates ATP
(energy!!)
Types of Energy
II. Solar Energy- energy from sunlight
i. can’t be used directly, must be
converted to chemical energy
Ways to get energy!
i. Autotrophs: make their own energy
Ex:
ii. Heterotrophs: have to eat to obtain
energy
Ex:
Autotrophs go through
Photosynthesis
I. process in which organisms convert
solar energy into chemical energy.
What do we need?
I. Starting Materials:
1. carbon dioxide (CO2)
2. Water (H2O)
3. sunlight
II. The Process
1.
Occurs in CHLOROPLASTS
2. Requires the pigment chlorophyll to capture energy
from light.
3. Rearrange molecules of water and CO2
2 Reactions Occur
1. Light Dependent Reactions: use light and
water to make molecules of ATP (energy) and
NADPH (helps make more energy). Oxygen is a
byproduct.
2. Light Independent Reactions (Calvin Cycle):
use carbon dioxide and ATP and NADPH from
light reactions to make GLUCOSE!
*does not need light!
Photosynthesis Animations
Light Reactions:
http://www.science.smith.edu/depa
rtments/Biology/Bio231/ltrxn.html
Dark Reactions (Calvin Cycle):
http://www.science.smith.edu/depa
rtments/Biology/Bio231/calvin.html
a. Oxygen
Products
b. Glucose (C6H12O6)
Other Products
Plant’s don’t immediately use all the glucose
they make!
-Stored as STARCH!
If leaves are the site of
photosynthesis… what happens
when leaves die and fall off for the
winter?
Read “Why do leaves change colors
in the fall” and answer the
questions. Finish for homework!
Do Now
1) Take out your homework
“Why do leaves change color in the
fall?”
Objectives
•
To explain why leaves change color in the
fall.
•
To list the reactants and products of
photosynthesis.
•
To explain the relationship between
photosynthesis and cellular respiration.
Practice Photosynthesis
Worksheet
By yourself or with a partner, please
work on the practice with
photosynthesis worksheet. When
you are done, return to your seat.
Do Now
-
What are the 2 reactions in
photosynthesis?
-
Where does each reaction occur?
-
Write the equation of
photosynthesis.
Objectives
-
To understand the process of cellular
respiration.
-
To compare and contrast photosynthesis with
cellular respiration
-
To explain what happens when our cells do not
get oxygen.
-
To explain the two types of fermentation.
All Cells Release Energy!
-
Aerobic Respiration = NEEDS OXYGEN!!
- In aerobic respiration we use oxygen to
help release the energy stored in bonds.
Cellular Respiration
i.
Occurs in MITOCHONDRIA!
ii. Creates LARGE amounts of energy.
iii. Process where cells break down glucose to give
energy to their cells.
Reaction
Starting Materials
a) Glucose (C6H12O6) – from plants
b) Oxygen – from breathing!
Process
break the bonds of the
starting materials
and rearrange them
to form new bonds.
3 Steps of Cell Respiration
1)
GlycolysisOccurs in the cytoplasm
-
We break glucose in half
( 2 pyruvates)
-
We make a small amount
of ATP
-
Make NADH (used to
make ATP)
3 Steps of Cell Respiration
2) Kreb’s Cycle (Citric Acid
Cycle)
-
Occurs in mitochondrial matrix
-
We take the broken glucose
and make more ATP, NADH,
and another molecule called
FADH2 which also helps make
energy.
-
We also release CO2
Products
1) CO2
2) H2O
3) ATP!! (Energy)
Do Now
-
What is the equation for cellular
respiration?
-
Where does cellular respiration occur?
-
What is the overall goal?
Review from yesterday…
-
What are the first two steps of cell
respiration?
-
Where do they occur?
-
What goes in? What comes out?
3 Steps of Cell Respiration
3) Electron Transport Chain
-
Occurs in mitochondrial membrane
-
Takes NADH and FADH2 and makes lots of ATP!
Uses Oxygen to make water.
Review!
1)
What is the goal of cellular respiration?
2)
What are NADH and FADH2
3)
What are the 3 steps of cellular respiration
4)
Where do each of the 3 steps occur?
5)
What do you think is going to happen if you don’t
have oxygen?
Partner Work
1)
You and ONE partner can work on the
“cellular respiration practice” worksheet.
What is Fermentation?
-
Without oxygen, cellular respiration cannot
continue.
FermenatFermentation
-
Fermentation is the process by which cells release
energy without oxygen. Occurs in cytoplasm.
Two Types of Fermentation
Alcoholic Fermentation- creates CO2 and “ethanol
alcohol” and little energy
- occurs in bacteria and yeast makes bread rise
and alcoholic beverages
Lactic Acid Fermentation- creates CO2 and “lactic acid”
and little energy
- occurs in muscle cells, yogurt, cheese
*Both types break sugars down to small molecules. A
small amount of energy is released.
Lactic Acid Fermentation