• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Respiration Revision Questions and Answers

Extracts from this document...

Introduction

F214 Communication, Homeostasis and Energy Module 4 Respiration 4.4.1 Respiration a. Outline why plants, animals and microorganisms need to respire, with reference to active transport and metabolic reactions All living organisms need energy so as to undergo their biological processes, of which all of the reactions are known altogether as metabolism. Metabolic reactions Those that build large molecules are anabolic. Those that break large molecules into smaller ones are catabolic. Active transport It is when ions and molecules are moved across a membrane against the concentration gradient. A lot of an organisms energy is used for this. Secretion When large molecules in some cells are removed via exocytosis. Endocytosis The movement of large molecules into the cell. Synthesis of large molecules from smaller ones. Replication of DNA and synthesis of organelles. Movement e.g. cilia Activation of chemicals. b. Describe the structure of ATP Adenosine= Ribose + Adenine Adenosine Monophosphate= Phosphate + Ribose + Adenine Adenosine Diphosphate= Phosphate + Phosphate + Ribose + Adenine Adenosine Triphosphate= Phosphate + Phosphate + Phosphate + Ribose + Adenine c. State that ATP provides the immediate source for biological processes ATP is a universal energy currency because it is in every living organism in cells, and energy can be created by losing a phosphate group and can be added to the molecule by adding a phosphate. ...read more.

Middle

m. Outline the Krebs cycle with reference to the formation of citrate from acetate and oxaloacetate and the reconversion of citrate to oxaloacetate and n. Explain that during the Krebs cycle decarboxylation and dehydrogenation occur, NAD and FAD are reduced and substrate phosphorylation takes place Krebs cycle Acetate is removed from the coenzyme a and joins with oxyaloacetate to form citrate. Citrate is decarboxylated (removing one carbon dioxide molecule) and dehydrogenated (removing a pair of hydrogen atoms) to form a five carbon compound. The pair of hydrogen atoms are accepted by NAD which makes Reduced NAD. The 5 carbon compound is decarboxylated and dehydrogenated to form a 4 carbon compound and another molecule of Reduced NAD is made. The 4 carbon compound is changed to another 4 carbon compound. Substrate level phosphorylation takes place where a molecule of ATP is produced by the phosphorylation of ADP. The new 4 carbon compound is changed into another 4 carbon compound. A pair of hydrogen atoms are removed and accepted by FAD to make Reduced FAD. This new 4 carbon compound is then dehydrogenated and makes oxaloacetate again. Another molecule of Reduced NAD is made. This happens once for every molecule of acetate so happens twice for every molecule of glucose. In total 6 reduced NADs, 2 reduced FADs, 4 carbon dioxide and 2 ATPs are made. ...read more.

Conclusion

Each pyruvate molecule loses a carbon dioxide molecule. So the pyruvate is decarbonised and becomes ethanal. The reaction is catalysed by the enzyme Pyruvate decarboxylase. Ethanal accepts hydrogen atoms from reduced NAD which becomes reoxidised. Ethanal becomes ethanol and is catalysed by ethanol dehydrogenase. v. Define the term respiratory substrate Respiratory substrate- An organic substance that can be used for respiration. w. Explain the difference in relative energy values of carbohydrate, lipid and protein respiratory substrates Carbohydrate Lipid Protein Energy value=15.8 kJg-1 Theoretically the respiration of 1 mol of glucose should be nearly 94 but it is more like 30 mol ATP. It has an efficiency of about 32%. Other monosaccharaides are changed to glucose for respiration. Energy value=39.4kJg-1 Each fatty acid is combined with CoA which needs energy from the hydrolysis of ATP to AMP. The fatty acid-CoA complex is transported into the mitochondrial matrix where it is broken down into 2-carbon acetyl groups. Reduced NAD and Reduced FAD is formed. When the acetyl groups are released from CoA they enter the Krebs cycle and make three molecules of Reduced NAD, one molecule of Reduced FAD and one molecule of ATP. Energy value=17.0kJg-1 When an organism undergoes fasting, starvation or prolonged exercise protein from muscles can be respired. Some can be converted to pyruvate, some to acetate and some enter the Krebs cycle directly. The number of hydrogen atoms accepter by NAD and used in oxidative phosphorylation is slightly higher than glucose so proteins release slightly more energy than carbohydrates. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Energy, Respiration & the Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Energy, Respiration & the Environment essays

  1. Marked by a teacher

    An investigation into the effect of different sugars on respiration in yeast.

    5 star(s)

    It ensures that the burette does not move. Plastic container To contain the water and beehive shelf during the experiment. N/A Rubber Tubing For the carbon dioxide to travel through from the solution into the burette. It prevents carbon dioxide from being lost into the surroundings.

  2. Marked by a teacher

    effect of temperature on the rate of respiration in yeast

    5 star(s)

    Volume of methylene blue: Volume of methylene blue should be kept constant because as the volume increases it will take longer for the yeast to become colourless because there will be more hydrogen produced by the yeast which then needed to be used by methylene blue which will take longer for the yeast to get back to his colour.

  1. Marked by a teacher

    'An investigation into the ability of two strains of the yeast Saccharomyces cerevisiae to ...

    4 star(s)

    As a result of the environmental demands placed upon the Narbonne strain, a higher tolerance to acidic conditions is likely to be a characteristic which differentiates it from strains not specialised in the fermentation of wine. The carbon source provided will ultimately be used within the cytoplasm of the yeast cells, during glycolysis.

  2. Marked by a teacher

    ATP or Adenosine Triphosphate.

    3 star(s)

    with the secondary oocyte; it can now clearly be seen that ATP is essential for sexual reproduction in humans, and the existence of humans. ATP has a role in synaptic transmission, where they release energy for resynthesis of synaptic vesicles, for example in the resynthesis of Acetylcholine, and possibly for

  1. the effect of bile concentration on the activity of the enzyme lipase during the ...

    for which base to use either sodium carbonate or sodium hydrogen carbonate and for quantity of these two bases we should use. We decided to carry out this test because my background information informed me that hydrogen carbonate ions were used in the body to neutralise the chyme produced by

  2. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    of the change in pH. I then divided the average by sixty to give the rate per second. I drew a graph using the rate and the bile salt concentration. Using the average change in pH, I divided it by sixty to give the rate per second in seconds-1.

  1. Investigating how prolonged exposure to its optimum temperature affects the respiration of yeast.

    This also means that if it is going to be exposed to a temperature which may kill the yeast that the yeast that does die will be minimised. As for the glass, the conductor must ensure that any broken glass is cleaned up immediately, and any cuts are healed before continuing the experiment.

  2. Why the Body Needs Energy? Every living cell within the ...

    cells within the body because the oxygen is getting to the cells. Reference: http://www.ivy-rose.co.uk/Topics/Respiratory_System.htm http://www.brianmac.co.uk/physiolr.htm Website viewed on 20/5/08 The Gross Structure of the Repertory System The nose is an organ on the face which acts as the first passageway for the air to entre the body The Structure of

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work