Science Starter1.18&21.13

Don’t forget to explain ALL answer choices!!

Cellular Respiration & Photosynthesis

*Life Science

*Plant Cell*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.

*Chloroplasts*2 main parts surrounded by membranes

*Grana - stacks of Thylakoids “coins”

*Stroma - aqueous space between the grana

*Photosynthesis

*Converts sunlight energy into food for the plant.

*Takes place in the chloroplasts

*Has a light (grana) and dark (stroma) reaction

*Formula for photosynthesis 6CO2 + 6H2O -> C6H12O6 + 6O2

*Photosynthesis: Overall Reaction

*6CO2 + 6H2O -> C6H12O6 + 6O2

*In other words:

*The reactants carbon dioxide & water in the presence of sunlight & chlorophyll yield to form the products glucose & oxygen.

*Light Reaction: Takes Place in the Grana

*Requires sunlight

*Photons from sun and water from plant come into grana

*Chlorophyll kicks off an electron from the splitting of H2O into hydrogen and oxygen

*ADP (low energy) is converted into ATP (high energy)

*NADP+ (low energy) is converted into NADPH (high energy)

*C6H12O6 = 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)

* Dark Reaction: Takes Place in the Stroma

*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

*Cellular Respiration

*Formula: C6H12O6 + 6O2 -> 6CO2 + 6H2O

*Both plants and animal cells utilize glucose & release the stored energy

*Energy released by cells is done mainly in the mitochondria

*Aerobic Cellular Respiration

*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

*Anaerobic Respiration

*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)