Flashcards
Biological energy
Cards in this deck (72)
- 1How can energy be stored? (2)Chemical bond formation
Holding something away from equilibrium - 2What are the four types of chemical bond formation (for energy storage)?1) ATP
2) Phosphocreatine
3) Other phosphate containing molecules
4) Sugar stores - 3Give examples of holding something away from equilibrium? (2)1) PMF
2) Chemiosmotic prinicple - 4Describe the structure of adenosine 5' triphosphate. How does it differ to ADP and AMP?1) 3 phosphate groups + ribose + adenosine
2) More phosphate groups - 5How does ATP store energy? (3)1) Through resonance and the 2) instability of the molecule due to the high negative charge (increases energy)/charge separation. 3) Reaction held far from equilibrium (ADP has a much lower energy potential). Bonds cannot be high-energy it is more to do with the environment they are in.
- 6What is resonance?Delocalised electrons can switch between atoms i.e across single O bonds. This lowers the potential energy of the complex making it more stable - the resonance energy is then the difference between the potential energy of the actual structure and contributing structure of lowest energy.
- 7How is energy released from ATP?By hydrolysis
- 8How is ATP formed?By the phosphorylation of ADP and AMP (di- and monophosphate)
- 9What it ATP continually cycled through?Between catabolism (synthesis) and metabolism (utilisation of ATP)
- 10How much ATP is in the body? How much is turned over every day?1) ~250g
2) >50kg/day - 11What is this?Adenosine monophosphate
- 12Why are the products of hydrolysis of ATP?
- 13How does a cell detect how much energy it has?The ratio of ATP and AMP
- 14What does breaking bonds require? What happens when a bond is made?1) Energy
2) Releases energy - 15What is this?Phosphocreatine
- 16How is phosphocreatine synthesised? Is this an anaerobic or aerobic reaction?By transfer of a phosphate group from ATP catalysed by creatine kinase. Anaerobic.
- 17What does phosphocreatine act as?An ATP buffer - it is a form of short term energy which is produced when ATP is low. GTP can be used in the place of ATP.
- 18Where does phosphocreatine play a particularly important role?In tissues which have high, fluctuating energy demands such as muscle and brain.
- 19What is this?Creatine
- 20What is presence of creatine kinase in the blood diagnostic of?Tissue damage
- 21What are other phosphate energy sources?Other nucleotides - i.e. GTP and UTP (add triphosphate to the nucleotdie)
- 22What are the two purines in DNA?Adenine and Guanine
- 23What are the three pyrimidines in DNA?Cytosine, uracil and thymine
- 24Where is the base attached to the pentose molecule in a nucleotide? What type of bond is this?1) 1'
2) Glycosidic bond - 25What are the two medium to long term stores of energy?1) Carbohydrate stores (medium term)
2) Fat stores (long term) - 26What is the 'carbohydrate store' in the body? Where is it stored? How is synthesis and breakdown controlled?1) Glycogen
2) Liver and muscle
3) Allosterically and reciprocally controlled - 27What is glycogen useful for?For fast anaerobic exercise
- 28Where fat stored? How would you describe its energy density?1) Mainly in adipose tissue
2) High energy density - 29How does the storage of glycogen and fat differ?Glycogen is a limited store while fat is a virtually limitless storage
- 30How does potential energy storage vary with distance from equilibrium?The further a system is from equilibrium the great its potential energy.
- 31What is the content of Gibbs energy equal to?Observed mass action ratio ([Bobs]/[Aobs])/equilibrium mass action ratio ([Beq]/[Aeq])
- 32—X
- 33What are both components of the electrochemical gradient due to? What does this result in?1) Due to ion gradients - particularly proton gradients
2) Potential energy for work in the cell - 34What is PMF?Proton motive force - an electrochemical gradient due to protons
- 35What is PMF coupling?The term coupling is used to describe the linking to ATP generation.
- 36Describe how energy is produce by mitochondriaProtons (H+) are pumped across the mitochondrial membrane across the H+ pump, using energy from the electron transfer system. This results in energy being stored in a chemical gradient across the membrane. This energy is then utilised through letting H+ back into the mitochondria to produce ATP (ATP synthase converts ADP+P into ATP).
- 37Who proposed that PMF could be harnessed to make ATP? What did he link this process to? What did he win?1) Peter Mitchell
2) Linked to osmosis, hence it is called chemiosmosis.
3) 1978 Nobel prize for chemistry - 38What contributes to PMF? (3) What in turn is PMF used for? (2) What is it exchangeable with? (1)Contributors:
1) Fat stores
2) Glycogen stores
3) Catabolism
Used for:
1) Heat
2) Active stores
Exchangeable with:
1) ATP - 39What contributes to ATP? (3) What is ATP used for? (4)Contributors:
1) Catabolism
2) Glycogen
3) Other phosphates
Uses:
1) Active transport
2) Muscle contraction
3) Anabolism
4) Phosphocreatine - 40What is biological energy?Converting ion gradient into ATP and vice versa
- 41Describe the structure of F1F0-ATPase. What is it responsible for?Cytosilic F1, membrane spanning F1, Axle between F1 and F0. Stator laterally.
Responsible for conversion for the production/breakdown of ATP.
- 42What is F1/F0?A very small motor
- 43Describe the structure and function of F0. How does this lead to the production of ATP?Alpha subunit in the membrane (static) and a c ring (rotates). There are two proton half channels (lower is I and exit through higher is II) in the alpha subunit (if it were full length protons would just pass through). Hydrogen ions have to moves sideways down their concentration gradient. The causes the c ring to rotate. The rotation changes how the F0 section interacts with F1. This causes a conformational change in the B subunit of F1 complex and ADP + Pi (inorganic phosphate) is converted into ATP.
- 44What is the type of ATPase in mitochondria?F-type ATPase
- 45What is the type of ATPase in lysosomes, how does this differ to that in mitochondria? What is the purpose of this? Where else is found?1) V-type ATPase
2) Converts ATP (across the A subunit) into rotational energy to pump H+ into the organelle.
3) This drops the pH of the lysosome (needs to be acidic for pepsin to work)
4) In the golgi apparatus and other organelles which require a regulated pH. - 46Describe the breakdown of glucose for energy in anaerobic conditions. Where does this occur?1) 2 ATP are added to glucose, a six carbon compound. Oxidation (loss of hydrogen) occurs and 4 ADP are converted to ATP to produce pyruvate acid. In yeast 2 ATP molecules are used to produce alcohol and CO2. In homolactic fermentation 2 ATP molecules are used to produce lactic acid.
2) Cytosol - 47Where does aerobic glycolysis occur? How does this differ to anaerobic?1) Mitochondria
2) Pyruvate acid in the presence of O2 is converted to CO2 + H20, catalysed by 34 ADP to 34 ATP - 48Describe glycolysis. What does it use and what does it produce?1) Can occur in the absence of oxygen.
2) Consumes two ATP molecules, and produces four ATP molecules and two NADH2+ molecules. - 49What are the products between glucose and pyruvate?2X glyceraldehyde 3-phosphate, addition of 2 phosphates results in 2 NADH molecules and 2X 1,3-diphosphoglycerate. This is then broken down into 2X 3-phohsphoglycerate 2 ATP molecules as bi-products. 3-phosphoglycerate is broken down into pyruvate,
- 50What is pyruvate from glycolysis used to generate? (2)1) Acetyl CoA for the citric acid cycle
2) Lactic acid - 51How is ATP generated?By substrate level phosphorylation - transfer of phosphate group from triose sugar to ADP
- 52How is ATP produced in aerobic metabolism of glucose? What acts as an electron carrier?1) The electron transfer chain in the presence of O2 - electrons taken from carbon molecules.
2) NAD - 53What is the TCA cycle? Where does it occur? What does it take the output of? What does it produce?1) The citric acid cycle
2) In the matrix of the mitochondrion
3) Output of glycolysis - extracts electrons
4) Carbon dioxide - 54What are the steps in the citric acid cycle?Pyruvate to:
1) Acetyl CoA
2) Citrate
3) Isocitrate
4) a-ketoglutarate
5) succinyl CoA
6) succinate
7) fumarate
8) Malate
9) Oxaloacetate - 55What happens to NAD+ at various points in the cycle? And what are these points?1) NAD+ is converted to NADH+ and H+ resulting in the production of CO2.
2) At step 1 (pyruvate to acetyl CoA), after step 3, 4, 5, 6 and 8. - 56How is energy created from electron transport? Why does it need O2?1) Electron transport chain couples reaction between an electron donor (such as NADH) and an electron acceptor (such as O2) (which releases energy) to the transfer of H+ ions.
2) Final stage is the passage of an electron on to oxygen and the production of water - hence O2 required. - 57Under aerobic conditions what are the electron donors? Which complexes do they form? Where do they enter from?1) NADH and FADH
2) NADH forms complex 1 with coenzyme Q reductase; FADH forms complex 2 with succinate coenzyme Q reductases. Both transfer electrons through UQ onto complex III (coenzyme Q + cytochrome C reductase). The other product which acts at complex III is CytC which is produced by Cytc oxidase (which converts 1/2O2 + 2H+ into O2 to produce Cytc). This contributes energy to the proton gradient.
3) Enter from the TCA cycle and into the mitochondrial inner membrane. - 58What does making larger biological molecules require? Give three examples.1) Energy - usually from ATP, anabolism
2) Protein synthesis, DNA replication, hormone/steroid synthesis. - 59Define anabolismThe synthesis of complex molecules in living organisms from simpler ones together with the storage of energy; constructive metabolism.
- 60What are the different kinds of transport?1) Passive
2) Active (uniport, symport, antiport)
- coupling
- secondary active
3) Charge dirven (link to PMF) - 61What does the transfer of glucose require? Why?1) ATP (active transport)
2) Glucose is moved against its concentration gradient - 62What is a pump which uses the majority of ATP? How many molecules are transported across the pump.1) Na+/K+ pump - breaks down ATP to ADP.
2) 3 Na+ are pumped out of the cell and 2 K+ are pumped into the cell. - 63What is secondary active transport (cotransport)? Give an example.1) Uses primary active transport of one molecule to transport a second
2) Many glucose transporters are linked to the Na+/K+ATPase - energy created by sodium gradient is used to frag glucose into the cell. - 64What do muscle cells contain? What are sarcomeres composed of? How does contraction occur and what does this require?1) Tubular myofibrils
2) Long fibrous proteins - actin and myosin
3) Actin and myosin slide over one another, requires ATP. - 65Describe the four steps of the contraction of myosin/actin
- 66What is turning PMF into heat?Uncoupling - thermogenin.
- 67What is thermogenin/how do UPCs work?Produces heat without shivering, uncoupling protein (UCP1). UCPs decrease the proton gradient generate in oxidative phosphorylation. They do this by increasing the permeability of the inner mitochondrial membrane. This allows hydrogen ions to return into mitochondrial space.
- 68Where does the production of heat through thermogenin occur?Mitochondria in brown adipose tissue (i.e. for infants)
- 69What are the four energy stores?1) ATP
2) Phosphate
3) PMF
4) Others - 70What are the sources of energy?Catabolism
- 71What are the four uses of energy?1) Anabolism
2) Transport
3) Motility
4) Heat - 72• Describe biological stores of energy • Explain how energy is transferred between these stores • Explain chemically how energy is stored in PMF and ATP. • Describe in overview where biological energy comes from and how it is turned into stores • Describe in overview the uses of biological energyX
Information
- Description
- Dr. M Roberts 13.10.17
- Created by
- Anna Hogarth
- Views
- 6
- Rating
More on ATP and High-Energy Phosphate Compounds