Bell Ringer 1/9/12 Happy New Year and welcome back! Answer the following on your blue sheet. Have your binder out and ready to be stamped! 1. Where do you get all of your energy to survive? 2. What type of consumer are we (herbivore/omnivore/carnivore)? 3. Are there more than one trophic level that humans can occupy? Explain.

Announcements Quiz re-takes for cellular organelles will be tomorrow during the first 20 minutes of class…so STUDY. HOMEWORK: –Due 1/12/12 (Thurs): Ch. 9 vocab index cards. p. 241 ALL of them. –Due 1/13/12 (Fri): All index cards from this semester should be organized and brought to class. Take out paper for notes.

Energy In A Cell Chapter 9

The Need for Energy (Ch. 9, Sec. 1) All organisms need ENERGY Plants (autotrophs) obtain energy from the sun Other organisms (heterotrophs) eat plants to get the plant’s stored energy

ATP (Adenosine Triphosphate ) Made of: –1 adenosine molecule –1 ribose molecule –3 phosphate (P) groups Energy is stored in the bonds between the phosphates –When the bond breaks, energy is released –When the bond is formed, energy is stored

Photosynthesis Ch. 9, Sec. 2

Photosynthesis = process in which plants use energy from the sun, carbon dioxide, and water to produce simple sugars and oxygen (byproduct) The chemical equation is: Solar energy + 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2  Memorize this! Occurs in 2 phases –Light-dependent Reactions –Light-independent Reactions

Why can plants and other autotrophs be photosynthetic? Chloroplasts and the pigments they contain. Chloroplasts: where photosynthesis takes place (contains chlorophyll)

Pigments = compounds that absorb light Visible Light made up of a range of colors ROY G BIVROY G BIVROY G BIVROY G BIV Colors that don’t get absorbed, are reflected, and are what you see

Electromagnetic Spectrum

Where are the pigments contained in the chloroplast? Within the Thylakoid Membranes Chlorophyll a and chlorophyll b give plants a green color What color light is absorbed by plants that appear green? What color light is reflected?

Carotenoids pigments in plants that become visible when plants stop producing chlorophyll Produce yellow and orange colors we see in the fall.

Light-Dependent Reactions 1 st phase of Photosynthesis, requires light energy Energy gets captured by electrons The energized electron splits a water molecule causing Oxygen to be released and ATP to be generated

Dark (light-independent) Reactions Calvin Cycle = 2 nd part of photosynthesis, does not require light –Uses CO 2 to form sugars –Takes place in the stroma of the chloroplast Generation of the sugars requires ATP produced during the Light-Dependent Reactions

Overall process of photosynthesis

End result…and purpose LDR: Occurs in thylakoid membrane –Input: water and sunlight –Output: ATP and oxygen Dark (LIR): Occurs in Stroma –Input: Carbon dioxide 6CO 2 –Output: Glucose C 6 H 12 O 6 The glucose produced is a form of stored energy to be converted to ATP then needed by an organism. –Glucose itself is not the actual energy. Think of it as a charged battery to be used later when needed.

Practice What are the inputs for photosynthesis? What are the outputs for photosynthesis? Is a product considered an input or output? Explain.