Science Starter 1.18&21.13 Don’t forget to explain ALL answer choices!!

Cellular Respiration & Photosynthesis

* Plants are autotrophs - they make their own food. * They use a process of photosynthesis to convert energy from the sun in the form of EMR into glucose. * Glucose stores the chemical energy until needed by the plant. * Photosynthesis takes place in the chloroplasts found in plant cells.

* 2 main parts surrounded by membranes * Grana - stacks of Thylakoids “coins” * Stroma - aqueous space between the grana

* Converts sunlight energy into food for the plant. * Takes place in the chloroplasts * Has a light (grana) and dark (stroma) reaction * Formula for photosynthesis 6CO 2 + 6H 2 O -> C 6 H 12 O 6 + 6O 2

* 6CO 2 + 6H 2 O -> C 6 H 12 O 6 + 6O 2 * In other words: * The reactants carbon dioxide & water in the presence of sunlight & chlorophyll yield to form the products glucose & oxygen.

* Requires sunlight * Photons from sun and water from plant come into grana * Chlorophyll kicks off an electron from the splitting of H 2 O into hydrogen and oxygen * ADP (low energy) is converted into ATP (high energy) * NADP + (low energy) is converted into NADPH (high energy)

* C 6 H 12 O 6 = glucose (sugar that is long term, high energy) * ATP = adenosine triphosphate (sugar that is short term high energy) * ADP = adenosine diphosphate (sugar that is short term low energy * NADP + = Nicotinamide adenine dinucleotide phosphate (enzyme that helps break down water and is low energy) * NADPH = Nicotinamide adenine dinucleotide phosphate (enzyme that is now carrying the hydrogen from the broken down water and is high energy)

* Takes place day or night...no sunlight required * ATP (high energy) and NADPH (high energy) along with carbon dioxide goes through the Calvin Cycle and converts them into glucose * ATP and NADPH are short term high energy molecules while ADP and NADP+ are short term low energy molecules * Glucose is a long term high energy molecule

In summary : Light reactions: photons, water, ADP, NADP+ in… oxygen, ATP, and NADPH out Dark reactions: Carbon dioxide, ATP, and NADPH in… Glucose, ADP, and NADP out

* Formula: C 6 H 12 O 6 + 6O 2 -> 6CO 2 + 6H 2 O * Both plants and animal cells utilize glucose & release the stored energy * Energy released by cells is done mainly in the mitochondria

* 2 part process * In the cytoplasm, a glucose molecule is broken into 2 pyruvate molecules (an acid that helps break down sugar) * In the mitochondria, the Krebs Cycle converts the pyruvate molecules into 36 ATP molecules

* 2 types: * Alcohol – yeast converts sugars into alcohol & releases energy * Lactic Acid - muscles without enough oxygen convert sugars to lactic acid to release needed energy for contractions (movement)