Cellular Respiration or WOW do I Need Energy ATP

All cells need energy. The most common form of cellular energy is ATP. Below is ATP It is the negative phosphate groups that give this molecule energy as it becomes unstable. When the phosphate is transferred to other molecules, those molecules have energy because they become unstable. ATP ___ > ADP + P is an exergonic reaction that releases energy.

Below is an example of a cell using ATP in the active transport of material across the membrane.

This is the potassium/sodium pump that uses ATP to pump across the ions.

This is a muscle fiber and it shows how ATP is needed to cause the muscle to contract.

A cell must be able to put the phosphate back on the ADP in order to keep living as all cells need energy. This is an endergonic reaction and requires an energy input. The source of energy needed to put the phosphate back on is food such as glucose. Just like a car uses gasoline for energy, cells use glucose as energy source to put the phosphate back on ADP.

Which of the following does not require ATP? A) The working of the sodium-potassium pump. B) The contraction of a muscle fiber. C) The disassociation of salt (NaCl) into Na + and Cl - ions. D) The synthesis of triose from carbon dioxide and water during the Calvin cycle.

C Salt when dissolve into water will automatically disassociate into Na + and Cl - ions. All the other three examples require ATP.

Just like the gasoline a car uses for fuel, the energy used by cells, comes from stripping the hydrogens from the glucose molecule. The difference that this must be on in step-wise fashion. This is an oxidizing reaction. Quite often when a molecule has hydrogen, it has increased energy.

This reaction is classified as A) an ionic reaction B) an endergonic reaction C) an exergonic reactin D) an exotherminc reaction

B To put a phosphate onto ADP energy is required. That classifies it as an endergonic reaction.

The energy produced from the "burning" of glucose is used to make ATP. In chemistry this process is called the oxidation of glucose. The energy in glucose must be released in steps instead of releasing it all at once. It would be like putting a match in gas can to release it all at once. Cellular respiration has three major parts with many steps in each part. 3 Part of Respiration I. Glycolysis II. Kreb's Cycle III. Electron Transport Chain

Which of the following has the most energy? A) ATP B) C 8 H 18 C) H 2 O D) NaCl

B C 8 H 18 has more energy because it is a long hydrocarbon chain without any oxygen. This is gasoline and has more energy than ATP.

How How is this reaction like burning gasoline in a car? A) This is an oxidizing reaction that releases energy. B) This is a reducing reaction that requires an energy input C) This is a reaction that happens all at once. D) This is a reaction that is spontaneous.

A When gasoline is “used” in an engine, it is an oxidizing reaction that is very explosive. The hydrogens are stripped off the carbon chain. The above reaction is not explosive but has many steps to it. Both reactions require oxygen and both release energy.

Where does glycoysis occur? A) in the mitochondrion B) in the chloroplast C) in the Golgi apparatus D) in the cytoplasm

D Glycolysis occurs in the cytoplasm.

Overview of Glycolysis I. Glycolysis-cytoplasm- Glucose----> 2 pyruvic acid 2NAD + 2H---->2NADH 2ATP---->2ADP + 2P 4ADP + 4P----> 4ATP NET 2 ATP for cell use

Glycolysis is does not need oxygen. This process occurs in the cytoplasm. Two net molecules of ATP are made for cell use. It involves glucose being converted to two molecules of pyruvic acid. Glycolysis involves glucose being converted to two molecules of pyruvic acid. This process is not very efficient at converting the energy of glucose into ATP as only 2 ADP are phosphorylated instead of 32 as in Krebs and chemiosmosis.

Glycolysis is does not need oxygen. This process occurs in the cytoplasm. Two net molecules of ATP are made for cell use. It involves glucose being converted to two molecules of pyruvic acid. Glycolysis involves glucose being converted to two molecules of pyruvic acid. This process is not very efficient at converting the energy of glucose into ATP as only 2 ADP are phosphorylated instead of 32 as in Krebs and chemiosmosis. The first four steps of glycolysis is called the investment phase because energy is put into the system instead being made. 2 ATP consumed rather than made.

Which of the following is true about glycolysis? A) It makes 32 molecules of ATP B) It produces carbon dioxide gas C) Glucose is broken down to two moleucles of pyruvate D) No ATP is used, it is only produced

C Glucose at the end of glycolysis is turned into two molecules of pyruvate. Four molecules of ATP are made but two molecules of ATP are consumed so the process “nets” two molecules of ATP. No carbon dioxide gas is produced.

Put the following molecules in order order of greatest energy to least amount of energy- Glucose-6-phosphate, ATP, Glucose, Fructose 1-6 biphosphate A) Glucose->Glucose-6-phosphate->Fructose 1-6->biphosphate->ATP B) Glucose-6-phosphate ->Glucose->ATP-> Fructose 1-6 biphosphate C) Fructose 1-6->biphosphate ->Glucose-6-phosphate->Glucose->ATP D) Fructose 1-6->biphosphate ->Glucose->Glucose-6-phosphate->ATP

C Carbohydrates when oxidized can generate a number of ATP molecules from ADP and P. So ATP will have the least amount of energy. Glucose and fructose are isomers of one another and contain about the same amount of energy BUT as phosphates are added to a molecules, the molecules becomes unstable. As molecules become unstable their energy increases. All that being the case, C is the correct order of sequence.

In the last 6 steps of glycolysis energy is harvested. 4 ATP are made and two NAD are reduced to form NADH. In the end, the glucose molecule is converted to 2 molecules of pyruvic acid or pyruvate. This will be shuttled to the mitochondrion where the last hydrogens will be stripped off to reduce more molecules of NAD and FAD.

Step 1 _____________ Glucose becomes glucose-6-phosphate. This requires the use of ATP. Glucose-6- phosphate is more unstable and has more energy than regular glucose. Energy is put into the system

In this step A) ATP transfers energy to glucose B) ADP gains energy C) Glucose loses energy D) No net energy is gained or lost during this step

A In this step ATP transfers energy to glucose. ATP becomes more stable as it loses a phosphate, this reduces the energy. Glucose becomes less stable as it bonds to a phosphate. This causes glucose increase in energy.

Step 2________________ Glucose-6-phosphate is turned into fructose-6- phosphate. Both of these molecules are hexose and have the same molecular formula. This is called isomerization.

Step 3_______________ Fructose-6-phosphate becomes 1,6 fructose biphosphate. This requires another ATP to be used. This new molecule is more unstable and has more energy than the old one.

Step 4_______________ This hexose is unstable, and will split to produce two trioses, dehydroxy acetone and PGAL. Dehydroxy acetone will turn into PGAL. From this point on, everything is multiplied by two.

Step 5________________ The PGAL will be turned into diphosphoglyceric acid. The molecule will lose hydrogen and gain inorganic phosphate. The hydrogen will be transferred to NAD to become NADH. NADH has more energy than NAD.

Step 6_________________ One of the phosphates from the molecule is transferred to ADP to make or phosphorylate ATP. The new molecule left is phosphoglyceric acid.

Step 7 This is a step that involves moving the phosphate group from the end carbon to the middle carbon. This increases the energy of the molecule. This makes it more unstable.

Step 8 This is a step that involves removing a molecule of water or dehydration.

Step 9_________________ This is a step that involves removing a phosphate and putting it on ADP or phosphorylating ADP to make another ATP. Now 4 molecules of ATP been made.

Summary of Glycolysis I. Glycolysis-cytoplasm- Glucose----> 2 pyruvic acid 2NAD + 2H---->2NADH 2ATP---->2ADP + 2P 4ADP + 4P----> 4ATP NET 2 ATP for cell use

After glycolysis, the pyruvic acid will go into the mitochondria, so that the rest of energy stored in the hydrogen can be extracted. If no there is no oxygen, then the Kreb's cycle can not completed. A cell can continue doing glycolysis in the absence of oxygen BUT it must regenerate NAD to keep going. This step of regenerating NAD from NADH is called fermentation. Anaerobic respiration = fermentation + glycolysis. The next step in the absence of oxygen, pyruvate will form either lactic acid (muscles) or ethanol (bacteria, yeast or plants). In either case NAD is regenerated so that glycolysis can continue. This is called anaerobic respiration. If oxygen is available, then the pyruvic acid will be shuttled to the mitochondria so that Kreb's cycle will take place.

The purpose of fermentation is to a.regenerate ADP + P from ATP b.make lactic acid c.make CO 2 d.regenerate NAD from NADH

D The limiting factor in glycolysis is NAD. That being the case, if there is no oxygen present and to continue with the glycolysis pathway, NAD must be regenerated from NADH. Fermentation (lactic acid or alcoholic) oxidizes NADH to regenerate NAD and allows glycolysis to continue.

After glycolysis, the pyruvic acid will go into the mitochondria, so that the rest of energy stored in the hydrogen can be extracted. If no there is no oxygen, then the Kreb's cycle can not completed. A cell can continue doing glycolysis in the absence of oxygen BUT it must regenerate NAD to keep going.