Question

Homework 3 (due 3/11) . Write a paper in which you follow the steps of one carbon, one hydrogen, and one oxygen atom as a glucose molecule goes through cellular respiration in the mitochondria, and then how each is used in photosynthesis within the chloroplast. e You will describe, for example, how one carbon molecule starts of in glucose, then go through the cycles until it is released as carbon dioxide from there, bring those byproducts into the chloroplasts to be used in photosynthesis to eventually form a glucose molecule and oxygen. Be thorough and descriptive in regards to enzymes, cycles, etc. . No required length, just do your best to understand how the element is rearranged in new compounds. . By 3/4, read about Photosynthesis (Unit 2)

Answer 1

Answer : Cellular respiration uses energy in glucose to make ATP.

The reactions of cellular respiration can be grouped into three stages : Glycolysis, The Krebs cycle , and Electron transport.

Glucose (6 carbons) C6H1206 Glycolysis in cytoplasm 4 ATP (2 net) Stage I 2 NADH Pyruvate (3 carbons) Pyruvate (3 carbons) 2 CO2 Stage II cycle 2 FADH2 2 ATP Oxidative Phosphorylation 34 ATP Net harvests 38 ATP Stage III

STAGE 1: The 1st stage of cellular respiration is Glycolysis. It takes place in the Cytosol of cytoplasm. Here the enzymes split a molecule of glucose into two molecules of pyruvate. These two molecules go on to the stage 2 of cellular respiration. The energy to split glucose is provided by two molecules of ATP. There net gain of two ATP molecules during glycolysis. During this stage high energy of electrons are also transferred.

STAGE 2: The 2nd stage of cellular respiration is Krebs cycle. Two molecules of pyruvate produced during glycolysis enter the matrix of mitocondrion, where they start Krebs cycle. At the beginning of Krebs cycle, Pyruvic acid, which has three carbon atoms, is split apart and combined with an enzyme known as CoA, which stands for coenzyme A. The product of this reaction is a two carbon molecule called acetyl- CoA. The third carbon from pyruvic acid combines with oxygen to form carbon dioxide, which is released as waste product. High energy electrons are also released and captured in NADH. After the turns through the krebs cycle, the glucose molecules has been broken down completely. All six carbon atons have combined with the oxygen to from carbon dioxide.

Krebs Cycle (Citric Acid Cycle) Pyruvic acid NAD NADH OCo2 Acetyl-CoA COA OAA (4C) Citric Acid (6C) NADH NAD NADH OCO2 NAD NAD NADH Oco2 FADH2 FAD ADP +P

STAGE 3: The 3rd stage (final stage) of cellular respiration is electron transport . In this stage, energy from NADH and FADH₂, is transferred to ATP. High- energy elctrons are released from NADH and FADH_2, and they move along electron transport chains, like those used in photosynthesis.

In all three stages of cellular respiration, up to 38 molecules of ATP may be produced from a single molecule of glucose.

Glucose is produce by the process of photosynthesis. This process takes place in the leaf chloroplast. Carbon dioxide and water molecules enter a sequence of chemical reactions within the chloroplasts.

The end product of these reactions are glucose and oxygen gas, which is released into the air. Glucose is used by the plant, with much of it being converted in the carbohydrates like starch and cellulose.