7 Photosynthesis & Cellular Respiration. 8-1 Energy and Life.
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Transcript of 7 Photosynthesis & Cellular Respiration. 8-1 Energy and Life.
7
Photosynthesis & Cellular
Respiration
Honors Biology 2009-2010
8-1 Energy and Life
Every living thing needs an input of energy; therefore, every cell needs an input of energy
Autotrophs: make own food; producers
Heterotrophs: consume food to get energy; consumers and decomposers
ADP ATP
Energy
EnergyAdenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)
Partiallychargedbattery
Fullychargedbattery
Figure 8-3 Comparison of ADP and ATP to a Battery
Go to Section:
Cells don’t keep a lot of ATP around because it doesn’t store a lot of energy. They convert carbohydrates into ATP as needed.
Glucose → ATP (there is more to this equation!)
Van Helmont – tested soil mass increase
Priestley – Found that plants release a substance that keeps a candle burning; we now know this substance is oxygen gas (O2)
Ingenhousz – Concluded that plants need sunlight to produce oxygen
8-2 Photosynthesis: An OverviewEssential Question: When a tiny seed grows into a tree, where does the increase in mass come from? Water? Soil? Air?
Word Equation for Photosynthesis
Chemical Equation for Photosynthesis
8-2 Photosynthesis: An Overview
Plants can then convert glucose (monosaccharide/simple sugar) into more complex sugars like starch or cellulose (polysaccharides/complex sugars)
Photosynthesis takes place in chloroplast of plant cells
Pigments – molecules that absorb light energy
Chlorophyll – plant’s principal pigment (different types); absorbs most colors and reflects green
p. 208: Inside A Chloroplast
9-1 (p. 221-222) Chemical Pathways
Glycolysis
the beginning of the pathway of converting glucose into cellular energy (ATP). Glycolysis only releases a little energy from glucose. IF oxygen is present, glycolysis is followed by additional chemical reactions which release more energy.
occurs in the cytoplasm; this is how prokaryotic cells make energy
Word Equation for Cellular Respiration
Chemical Equation for Cellular Respiration
Overview of Cellular Respiration (p. 222)
Cellular Respiration: process of releasing energy by breaking down food molecules in the presence of oxygen (aerobic respiration).
3 Stages of Cellular Respiration:
1. Glycolysis – cytoplasm; no oxygen needed; little energy produced
2. Krebs Cycle
3. Electron Transport Chain
Both occur in mitochondria; oxygen needed, a lot of energy produced
Both plants and animals do cellular respiration!
Fermentation (anaerobic respiration)
If no oxygen present, ATP will still be made but there is additional waste produced
Alchoholic Fermentation: yeast cells produce ATP anaerobically and produce the waset alchohl; used to make dough, wine, rootbeer!
Lactic Acid Fermentation: some animal cells will produce ATP if oxygen is limited and produce lactic acid waste; occurs during high energy usage (exercise)!