Post on 02-Jan-2016
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UNIT 5: PHOTOSYNTHESIS& CELLULAR RESPIRATION
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ENERGY AND LIFE Living things depend on energy
Sun is source of most energy
2 types of organisms, – AUTOTROPHS make their own food (Ex: plants,
bacteria*, protists*)– HETEROTROPHS get energy from the foods they
consume (animals, fungi)
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KEY CONCEPT: PHOTOSYNTHESISThe overall process of photosynthesis produces sugars that store chemical energy.
Photosynthetic organisms are producers.
Plants use photosynthesis and are producers/(autotrophs.)
Photosynthesis captures energy from sunlight to make sugars.
Research On Photosynthesis
– VAN HELMONT- determined in the 1600’s that plants grew because of water.
– PRIESTLEY- found that plants release oxygen.
– JAN INGENHOUSZ- found aquatic plants produce oxygen bubbles in the light, therefore plants need sunlight to produce oxygen
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AN OVERVIEW OF PHOTOSYNTHESIS
Plants use the energy of sunlight to
– convert water & carbon dioxide into high energy carbohydrates (sugar)
– oxygen is a waste product.
light
6H2O + 6CO2 → C6H12O6 + 6O2
Reactants Products
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What Else Does The Photosynthesizer Need?
Chlorophyll- a chemical pigment that traps the energy of the sun and converts it to chemical energy
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Capturing Light Energy
White light= ROY G BIV Chlorophyll captures (absorbs) energy at the
ends of the spectrum (red/orange & blue/violet) What you see is the wavelengths that are
reflected. (green)
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Where Photosynthesis Occurs
In the chloroplast
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Chlorophyll is a molecule that absorbs light energy.
chloroplast
leaf cell
leaf
• In plants, chlorophyll is found in organelles called chloroplasts.
Where Photosynthesis Occurs
Photosynthesis is Many ReactionsThe equation for the overall process is:
6CO2 + 6H2O C6H12O6 + 6O2
C6H12O6
granum (stack of thylakoids)
thylakoid
sunlight
1 six-carbon sugar
6H2O
6CO2
6O2
chloroplastchloroplast1
2
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energy
stroma (fluid outside the thylakoids)
FACTORS THAT AFFECT PHOTOSYNTHESIS
Amount of Water
Amount of CO2
Temperature
Intensity of Light
Wavelength of light
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KEY CONCEPT The overall process of cellular respiration converts sugar into ATP (energy) using oxygen.
Cellular Respiration
CHEMICAL ENERGY AND ATP
All living things use chemical energy A chemical compound that cells use to store and
release energy is ATP (ADENOSINE TRIPHOSPHATE).
ATP is like a fully charged battery ready to power the machinery of a cell.
ATP powers many cellular activities Ex: – active transport across cell membranes, – protein synthesis – muscle contraction.
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Cellular respiration makes ATP (energy) by breaking down sugars.
Cellular respiration is aerobic, or “requires oxygen.”
Cell respiration takes place in mitochondria.
mitochondrion
animal cell
Cellular Respiration
6H O2
6CO 2
6O 2
mitochondrionmitochondrion
matrix (area enclosedby inner membrane)
inner membrane
ATP
ATP
energy
energy from glycolysis
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2
4
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and
and
and
• The electron transport chain produces a large amount of ATP (energy.)
– oxygen enters process
– PRODUCT
– ATP
– WASTE PRODUCTS:
– Water
– Carbon dioxide
Electron Transport
Cellular Respiration
The equation for the overall process is:
C6H12O6 + 6O2 6CO2 + 6H2O
• The reactants in photosynthesis are the same as the products of cellular respiration.
Cellular Respiration
ATP synthase (don’t copy)
Is an enzyme (“-ase” ending is a hint)
Is a membrane protein.
It is a protein pump that allows H+ ions to pass thru the cell membrane
This is necessary for the formation of ATP
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Quick Review of Organic Molecules in Living Things
Carbohydrates (sugars, starches, etc.) Proteins Lipids (mainly fats) Nucleic acids (ATP, NADP, RNA, DNA)
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Cellular Respiration
• Cells do not “burn” glucose, instead they slowly release energy from glucose
• They do this in many small steps-
• WHY?
If all the energy was released once, it would be too much for the cell
and it would be destroyed!20
When O2 is not present, a process called FERMENTATION takes place.
FERMENTATION releases a small amount of ATP (energy) from sugar.
ANAEROBIC RESPIRATION
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1. ALCOHOLIC FERMENTATION produces carbon dioxide and alcohol.
This type of fermentation causes bread dough to rise.
.
2 Types of Fermentation
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2 Types of Fermentation, cont.
2. LACTIC ACID FERMENTATION is produced in your muscles during rapid
exercise when the body can’t get enough oxygen to the tissues.
With rapid exercise your muscles run out of oxygen. Your muscle cells rapidly begin to produce ATP by LACTIC ACID FERMENTATION
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Fermentation
Also occurs in the CYTOPLASM
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