Flashcards in Cellular process Deck (89):
Examples of biological process requiring energy
- Mechanical work, e.g. muscle contraction
- Synthesis of complex biomolecules from simple precursors
- Generation of light (fireflies) and electricity (eels)
- Active transport/ Neurotransmission
What is Heterotrophy?
Getting energy and volume from other organsims
What is chemotrophs?
Getting energy from chemical redox reaction
What is autotrophy?
getting energy from sunlight and volume from CO2 in the atmosphere
Glucose is break down into _________ by _________
Pyruvate can break down into ____?
- Aerobic metabolism > Acetyl CoA (& CO2 & NAD+)
- Anaerobic metabolism > Ethanol (& CO2 & NAD+) or Lactrate (no CO2 but NAD+)
What is the Net production of ATP of glycolysis ?
Further ATP id produced by __________
What is ATP ?
Adenosine triphosphate. The energy currency of cell
Fats will be break down into ?
fatty acids and glycerol
Polysaccharides will be break down into ?
Glucose and other sugar
Protein will be break down into ?
Where does the critic acid cycle take place?
in the mitochondria
What is NADH?
A carrier of high energy e-
Pyruvate is combined with __________ to form Acetyl CoA, with release of ________ and production of _________
coenzyme A (CoA)
Reaction within cells is important for ____________
- Synthesis of percursors
- Provision of energy
In metabolism, hundreds of ______________ occur
enzyme- catalysed reactions
ATP + H2o --> __________
ADP + Pi + energy
For ATP hydrolysis, AG = ?
- 7.3 kcal mol-1
What is released when ATP is broken down?
So ATP is broken down in ________________
Large amount of energy
carefully controlled process and catalysed by enzyme
________ is needed to synthesis ATP efficiently so ___________ L of air needed to be breathe everyday
O2, 10,000 L
Turnover of ATP is high/ low?
In a sprinter, average lifespan of 1 molecule of ATP is _____
A human hydrolyses about _____kg of ATP in 24 hours, if a person weight 70kg. And the total body ATP for is?
55kg > 50g
Different type of ATP production
- Substrate level phosphorylation
- Oxidative phosphorylation
IF the formation of ATP is directly from metabolism pathway, it's called _________
Substrate Level Phosphorylation
What is oxidative phosphroylation?
Process of ATP formation in the electron transport chain
90% of ATP in animal is formed by this method
What is acetaldehyde?
it is broken down from pyruvate and needed to be broken down again to enthanol
During glycolysis, NAD+ is converted to ________,
Glycolysis can't continue if ______ decreased
In aerobic metabolism, electrons on ________ is transferred to _________ via________________, to produce _____________
electrons on NADH transferred to O2 by electron transport chain to produce H2O, ATP, and NAD+
In anareobic metabolism, electrons on __________ transferred to _________ to form ___________
electrons on NADH transferred to pyruvate to form ethanol / lactate and NAD+
During extreme muscular activity, the oxygen delivered to the muscle is _______than the oxygen requirement for ______________
less than , NADH oxidation
What is lactate dehydrogenase?
Enzyme that convert pyruvate > (NADH + H+ -> NAD+) > Lactate
Oxygen debt is repaid in ___ mins by ____________
30 mins, by converting lactic acid to glucose in liver
Describe how body response to lactic acid production during anareobic activity
- Lactic acid dissociate to lactate & H+
- The pH decrease as H+ increased
- Muscle pain and fail to contract
- Activity decreases
Describe how blood doping aid the anareobic exercise performance
haemoglobin has many ionisable amino acids which may act as a buffer in skeletal muscle, which can resist the decrease in pH cause by lactic acid production
Vertebrates are mainly aerobic organisms T/F
Smaller vertebrates rarely rely on_________
Larger vertebrates are often ____ moving and rarely undertake _____________activity
anaerobic metabolism. e.g. migrating birds fly large distances without producing an oxygen debt.
slow moving, rarely undertake intense musclar activity. e.g. elephants and aligators.
In aerobic conditions yeast break glucose down to ___________
Yeast cells produce _________during ____________ metabolism.
carbon dioxide and water
ethanol , anaerobic
Ethanol is toxic to humans but produces feelings of
Humans produce______ during anaerobic metabolism – not ___________
lactic acid ,
not ethanol !!!
Acetyl CoA converted into_____________________
2 CO2, 8 high energy electrons and GTP
High energy electrons released at the citric acid cycle are transferred to ________________
NADH and FADH2
Describe citric acid cycle
C2 added to the C4 in the citric acid cycle C6 and produce CO2 & NADH become C5 and produce CO2 & NADH again become C4 and give out GTP, next give out FADH2 and then NADH. The remain C4 start the cycle again
The released electrons are then transferred to oxygen in oxidative phosphorylation to produce ATP
Describe the oxidative phosphorylation
The 8 e- from citric acid cycle are transferred in an electron transport chain down a series of carrier. The energy is released and used to pump the H+ ions out of the mitochondria matrix into space between the inner and outer mitochondria membrane to create a concentration gradient. The gradient is then used by the ATP synthase to produce ATP. ATP synthase is located in the mitochondria membrane and as H+ ions pass back down their concentration gradient through the narrow channel in the enzyme the energy of their flow is used to drive the production of ATP. Ultimately the electrons and H+ions are transferred to oxygen to produce water in overall reaction
Overall a molecule of glucose generates how many molecules of ATP?
~ 30 molecules
What are the major electron carriers in the oxidation of fuel molecules
NADH & FADH2
In aerobic organisms how many ATP is generate from glucose oxidation.
26 (out of the overall 30 ATP)
Name 2 metabolism disorders
- Mercury and Arsenic toxicity
- Berberi - thiamine (vit B1) deficiency
What is Beriberi?
thiamine (Vit B1) deficiency
- Neurologic and cardiac symptoms – limb pain, muscle weakness, enlarged heart and reduced cardiac output.
-Thiamine important in pyruvate and a -ketoglutarate dehydrogenase. These are important enzymes in the citric acid cycle.
- Neurological symptoms as neurological tissue particularly reliant on glucose metabolism and therefore pyruvate dehydrogenase.
What is mercury and Arsenic toxicity?
- Mercury and arsenic inactive pyruvate dehydrogenase.
- Symptoms similar to beriberi.
- Neurological symptoms
- The phrase “mad as a hatter” refers to hatters who were poisoned by mercury used in making hats.
Oxidative phosphorylation is involved of _____________
- electrons transport
- synthesis ATP
The electron transport chain consists of a series of _________
- oxidation/reduction (redox) couples
- 3 protein complex
- 2 mobile electrons carriers
redox couples interact to carry out the overall reaction:___________
Energy is released at each redox reaction T/F
NADH + H+ 1/2 O2 -> NAD+ + H2O
What is Cyanide?
A chemical compound that blocks electron flow through cytochrome oxidase by reacting with the ferric form of a heme in the complex.
What is used to treat the cyanide block?
Nitrite has been used in treating cyanide poisoning as it oxidises ferro hemoglobin to ferri hemoglobin which can then complete with the cytochrome oxidase for cyanide.
Describe the electron transport chain
1st: (NADH) 2 e- > NADH-Q reductase > Q & energy
2nd: FADH2 & Q > Q-Cytochrome C oxidoreductase > Energy & Cytochrome C
3rd: Cytochrome C & Cytochrome C oxidase > energy & 2H+ + 2e- + 1/2 O2 H2O
How is energy released converted to ATP in the oxidative phosphroylation?
The chemiosmotic hypothesis – Electron transport and ATP synthesis coupled by a proton gradient
Where is the ATP synthase?
in the mitochondria membrane
Can the proton gradient be measured?
Evidence to support the chemiosmotic hypothesis
- A proton gradient can be measured
- ATP synthesised if gradient created
- Vesicles with ATP synthase and bacteriorhodopsin synthesise ATP when illuminated.
- Closed compartment and intact membrane required
- Ionophores uncouple oxidation and phosphorylation.
During the oxidative phosphorylation, ATP is generated by:_________
Electrons flow from NADH or FADH2 to oxygen via a series of redox couples in the electron transport chain.
Energy released by electron flow is converted to ATP by __________
- Protons (H+) are pumped out of the matrix to generate a proton motive force.
- ATP is generated by ATP synthase when protons flow back into the matrix.
NADH yields how many ATP?
~ 2.5 ATP
FADH2 yields how many ATP?
~ 1.5 ATP
How many ATP is yield at each stage?
Glycolysis = 2 ATP
Citric aid cycle = 2 ATP
Oxidative phosphorylation = 26 ATP
Total = 30 ATP
what is Photosynthesis?
organisms use energy from sunlight and CO2 from atmosphere to produce glucose
Photosynthesis takes place in
Chloroplasts are _________ organelles in _____ cells.
subcellular , plant
Chloroplast structure have________
inner membrane/ outer membrane / stroma / stroma lamellae/ thylakoid membrane / intermembrane space/ thylakoid space
Plants are usually green because _____
Chlorophyll absorbs red and blue light and reflects green light.
Chlorophyll is a haem like structure with a ___________ ion at the centre of the structure.
Other __________ absorb light not absorbed by chlorophyll.
The actual colour of the leaf is determined by the_______________
relative concentration of the pigments.
Complex photosystems exist to _________
to channel light energy to the reaction center.
Which molecules absorbed light, then transfer between other, until it reacts the reaction centre?
- Antenna Chloroplasts
- Other Accessory pigments
The role of chloroplast reaction centre
Photochemical reaction occurs to convert the energy of a photon into a separation of charge, initiating electron flow
How the absorption of light energy affects the electron
leads to the excitation of an electron from its ground state to a higher energy level.
Photosystems generate _________, which _______drives ATP synthesis.
NADPH and a proton gradient.
The proton gradient
What is produced in photosynthesis ?
in chloroplasts, the energy harvested and ATP synthesised is used to drive synthesis of ______
The role of atmospheric carbon dioxide in global warming
Many scientist believe that increase atmospheric carbon dioxide concentration is causing an increase in the temperature of the planet.
example of Greenhouse gasses
- Carbon dioxide (mainly produced by oxidation of fossil fuels
- Methane (Produced by landfill and animals) – methane is a very potent greenhouse gas.
Measurement of atmospheric carbon dioxide over time
- Measure concentration of carbon dioxide in arctic and Antarctic ice caps
- Ice has been stored in the ice icecaps for many years.
- Collect ice from many years ago and date using carbon dating.
Describe vertical sampling of the atomosphere
- Global measurements for baseline understanding of CO2 but more detailed information required to understand regional impacts.
- Vertical sampling network being developed over North America to determine distribution of CO2 throughout the height of the atmosphere.
Relationship between CO2 and temperature
- During last ice age (15,000 to 30,000) years ago carbon dioxide levels very low
Warm interval 5000 years ago higher than today.
- Long-term record suggests high CO2 associated with high temperature low CO2 associated with low temperature.
Modern causes of increased CO2
- Oxidation of fossil fuel
- Carbon released into atmosphere as carbon dioxide.
Interventions to reduce CO2 emissions
- Wind power
- Bio fuel
Arguments against climate change.
- The Earth's climate is always changing and this is nothing to do with humans.
- CO2 only makes up a small part of the atmosphere and so cannot be responsible for global warming.
- Rises in the levels of CO2 in the atmosphere are the result of increased temps, not the other way round.
- Observations of temp taken by weather balloons and satellites do not support the theory of global warming.
- Computer models which predict the future climate are unreliable and based on a series of assumptions.
- It's all to do with the Sun - for example, there is a strong link between increased temp on Earth with the number of sunspots on the Sun.
- The climate is actually affected by cosmic rays.
- The scale of the negative effects of climate change is often overstated and there is no need for urgent action.
About bio fuel
- Burn biomass
- Carbon still released as CO2 but this carbon recently trapped from atmosphere.
- Completion between biofuel crop production and food crop production.