Lecture 9 - chemotrophy Flashcards Preview

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Flashcards in Lecture 9 - chemotrophy Deck (13):
1

Explain the difference between catabolism and anabolism

Catabolism is the process by which organisms obtain its energy and raw materials from nutrients. The breakdown of a large molecule for energy and materials. Anabolism on the other hand uses energy and raw materials to build macromolecules and cellular structures.

2

What are chemotrophs give example

Chemotrophs are organisms which get their energy source from chemical energy. The chemical energy is produced through oxidation of chemical compounds to produce ATP.

3

Provide equation for aerobic respiration and oxygenic photosynthesis

Aerobic respiration: chemical energy(sugar/protein/fat) + oxygen → water + carbon dioxide + ATP
C6H12O6(glucose) + 6O2 → 6CO2 + 6H2O + ATP

Oxygenic photosynthesis: carbon dioxide + water + light energy → oxygen + chemical energy(sugars)
CO2 + light energy → C6H12O6 + 6O2

4

Describe what is meant by substrate level phosphorylation what are the three examples?

An enzyme is involved in the phosphorylation. It is the transfer of phosphate group from phosphorylated compounds (substrate) directly to ADP (Phosphorylation of ADP → ATP). Examples, glycolysis, TCA cycle and fermentation.

5

What is the difference between substrate level and oxidative phosphorylation?


Substrate level phosphorylation includes an enzymes, it is the phosphorylation of ADP → ATP. Examples include glycolysis, TCA cycle and fermentation. Oxidative phosphorylation occurs in cellular respiration where there is a series of redox reactions down an electron transport chain.

6


What is fermentation? What are the similarities and difference compared with anaerobic respiration?

Fermentation is a FORM of respiration in that it does not require oxygen. However, it is not exactly anaerobic respiration as it does not recycle NADH. Both begin the same with the breakdown of carbohydrate (Glycolysis) however it does not produce pyruvate depending on the fermentation process.

7

What is meant by oxidation and reduction?

Oxidation is where there is a loss of electron whereas reduction is the gain of electrons during a chemical reaction.

8


Describe the aerobic cellular respiration process.

Aerobic cellular respiration is a process where Glucose is converted to ATP using oxygen as the final exogenous electron acceptor. It involves 4 protein complexes with a series of redox reactions.

9

Briefly describe the process of anaerobic respiration and give one example with substrates and products

Anaerobic respiration is cellular respiration that requires O2 as the final exogenous electron acceptor. It involves 2 protein complexes with oxidative phosphorylation of electrons down an electron gradient to produce convert ADP → ATP.

10

Describe the differences between aerobic and anaerobic respiration

Aerobic respiration is respiration that requires oxygen in the process. It is a redox reaction that processes energy in a form usable by organism. It uses electron transport chain with O2 as final exogenous electron acceptor.

Anaerobic respiration is oxidative phosphorylation without O2. It uses electron transport chain with inorganic molecule such as Sulphur. I.e. Sulfur reducing bacteria

11


Briefly describe the process of anaerobic respiration and give one example with substrates and products

Anaerobic respiration is cellular respiration that requires O2 as the final exogenous electron acceptor. It involves 4 protein complexes with oxidative phosphorylation of electrons down an electron gradient to produce convert ADP → ATP.

12

Compare chemo-organotrophy and chemo-lithotrophy, Give examples of each

Chemo-organotrophy are organisms that oxidise organic compounds (acetate, glucose, benzene or methane) acting as electron donors. Chemo-lithotrophy on the other hand use reduced inorganic compounds as as source of energy. Examples of organisms include sulfur oxidisers, nitrifying bacteria (Nitrosomonas nitrosa), iron oxidisers (Azospira oryzae) and hydrogen oxidizers (Ralstonia eutropha ).

13

What is the fundamental difference between autotrophs and heterotrophs?


Autotrophs can make their own food therefore they utilize CO2 as their main carbon source. Heterotrophs cannot synthesize their own food therefore they use carbon from organic molecules i.e. Carbohydrates, fats and proteins.