Download Getting Energy and Matter into Biological Systems

Getting Energy and Matter
into Biological Systems
+
Write a
statement that
explains what
is taking
place in this
picture
Review
• We, living organisms, need ________ in
order to survive.
• Molecules like _________, ________, and
_________ found in food provide us this.
• Molecules are made of ____________
such as Carbon, Hydrogen, Oxygen, etc.
• These ___________ are what make up
matter.
• So how do we get matter found in food in
the first place? Who/what gets the credit?
Photosynthesis!
The process by which plants, some protists,
and some bacteria use energy transferred
from the sun to...
…synthesize LARGE, energy rich molecules
from small ones. What do plants make?

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CO2
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Things that may affect the rate of
photosynthesis:
– Intensity of light
– Amount of CO2
– Water availability?
– What else?
– Color of light?
– Toxins?
– Soil nutrients?
A Plant Cell
Where does PS happen?
• All plants are made up of plant cells
• Most plant cells contain chloroplasts,
which make them appear green
• Inside chloroplasts, there are structures
called thylakoids
• In the thylakoid membranes, chlorophyll
is stored
• Chlorophyll is a pigment that absorbs the
sun’s energy
• Light energy from the sun hits the
chlorophyll molecules
• Much of the light energy is
absorbed but one wavelength of
light is reflected off, not absorbed.
• This is the “color” of light that you
see.
3 major events, but 2 “phases”
1. Absorption of light energy
2. Conversion of light energy into
chemical energy  1st PHASE
outcome:
3. Storage of chemical energy in the form
of carbs a.k.a. glucose 2nd PHASE
outcome:
How do you “fix” Carbon?
Bottom of a leaf
Cross-section of a leaf
Carbon Fixation is the
process that converts
atmospheric Carbon
Dioxide into carbohydrate
molecules (glucose, etc.)
Why does photosynthesis happen?
• Autotrophs use PS to get and store
energy (as ___________)
• Heterotrophs eat autotrophs and use
these carbohydrates as energy sources
The Big Picture…
Reactions
• Photosynthesis
• Cell Respiration
Connect PS and CR reactions to
Endo and Exothermic reactions…
Video Clip
http://www.teachersdomain.org/9-12/sci/life/cell/photosynth/index.html
Homework due Wednesday
• Read Essay in textbook, Getting Light
Energy into Biological Systems, p.367
• Complete the first half of Photosynthesis
Review WS