5 - ICH - Respiration Flashcards
Define respiration
The breakdown of organic respiratory substrates to release some of their chemical energy
Define and give an example of each:
- Aerobic respiration
- Anaerobic respiration
- Obgligate anaerobes
- Facultative anaerobes
- Respiration in the presence of oxygen
- Respiration in the absence of oxygen
- Orgamisims which can only respire anaerobically e.g. Denitrifying bacteria
- Organisms that respire aeroibcally if oxygen is available and anaerobically if oxygen is unavailable e.g. humans and yeast
What is the first law of thermodynamics?
Energy can not be created or destroyed but can be converted from one form to another
What is the universal energy currency?
Structure?
ATP
What is the unit for energy?
Joule (J) but most of the time it’s in kilojoule (KJ)
Name 7 processes that require ATP?
- Active transport
- Bulk transport (exocytosis/endocytosis)
- Synthesis of larger molecules from smaller ones
- DNA replication
- Organelle synthesis
- Movement of whole cells and of organelles and molecules within cells
- Maintenance of body temperature (endotherms)
What is ATP?
It is the energy currency for cells. It can be regarded as a temporary energy store and a means of transferring energy.
What reaction does ATP undergo to release energy?
ATP is hydrolysed to produce ADP + Pi
- What is the approximate amount of energy released per ATP molecule?
- Why is this a sufficient amount?
- Approx 30.6KJ energy released per molecule of ATP.
- Human body only contains around 5g of ATP at any given time. It’s constantly being cycled and replaced.
Where does it occur?
- Aerobic respiration
- Anaerobic respiration
Aerobic respiration = Matrix of the mitochondria
Anaerobic respiration = Cytoplasm
Define:
Anabolic reactions
Catabolic reactions
Metabolism
Anabolic reactions = Build up chemical reactions in which smaller molecules are combined to form larger ones. Requires energy that is usually provided by ATP.
Catabolic reactions = Breakdown chemical reactions in which larger moelcues are broken down to form smaller ones and release enrgy which can be used to synthsise ATP.
Metabolism = All the chemical reactions occuring in a cell or a organism.
Give 2 reasons why ATP is useful as an intermediate source of energy?
- Breakdown of ATP is a single step reaction making energy instantly available.
- Breakdown of ATP releases a small amount of energy ideal for powering an anabolic reaction without the release of learge amounts of surplus energy (heat)
Define the 3 ways to synthesise ATP.
What enzyme is used to calatyse these reactions?
Photophosphorylation = Takes place in the light dependant reaction of photosynthesis.
Oxidative phosphorylation = Take splace on the inner mitochondrial membranes during the process of electron trasport.
Substrate-level phosphorylation = Occurs when ATP is made directly without the involevement of oxidative phosphorylation.
Enzyme = ATP synthase otherwise known as ATPase
What reactions of respiration occur in the mitochondria?
Link reaction, krebs cycle and oxidative phosphorylation
Describe the structure of mitochondria
Inner folded membrane (crista) = Contains proteins attaches that are involved in the electron transport chain. Oxidative phosphorylation occurs here. Folding provides max SA for molecules involved in the electron carrier system and ATP synthase.
Intermembranal space = Fluid-filled/ lies between the outer and inner mitochondrial membranes. Hydrogen ions/protons are pumps into this space and a proton gradient is set up.
Stalked particles = Provides a channel for the return of hydrogen ions/protons into the matrix and contains enzymes involved with ATP synthesis e.g. ATP synthase and therfore is responsible for poducing ATP by chemiosmosis.
Matrix = Contains enzymes involved in the link reaction and krebs cycle. This is where those processes occur.
Apart from enzymes for the link reaction and krebs cycle what else does the matrix contain? (3)
- Circle fo DNA
- 70s ribosomes
- Phosphate granules (for ATP synthesis)
Describe the Endosymbiont theory of mitochondria origin
Where in the body do you find lots of mitochondria?
What is particular about the mitchondria in such cells?
Mitochondria occur in their greaest numbers in cells that are very metabolically active: Liver and muscle cells
Mitochondria in these cells have more densely packed cristae to increase the SA for attachment of the proteins involved in oxidative phosphorylation.
Name the 3 coenzymes that are involved in respiration?
NAD
FAD
coenzyme A
Name and state the purpose of the enzyme sinvolved in repiration (5)
Hydrolase = Catalyses a hydrolysis reaction
Dehydrogenase = Catalyses the removal of hydrogen
Isomerase = Catalyses te conversion of one isomer of a compound to another
Decarboxylase = Catalyses the removal of CO2
ATP synthase = Involved in ATP synthesis from ADP + Pi
Give the equations for:
Aerobic respiration of glucose
Anaerobic repiration of glucose in animals
Anaerobic respiration of glucose in plants/ yeast
What is thr ATP production difference? Why is this?
For Aerobic respiration of glucose the theoretical value is 38ATP per molecule of glucose.
In reality it’s more like 30-32ATP because there’s some proton leakage.
What is another name given to the anaerobic respiration of yeast?
What are it’s uses? (2)
Fermentation
Used comercially for making alcoholic drinks and in baking where the CO2 makes the bread rise.
What is the simple equation for respiration?
Why is this equation misleading? (3)
C6H12O6 + 6O2 → 6CO2 + 6H2O (+ Energy)
- Glucose may not be the only respiratory substrate.
- Equation shows O2 being used (areobic respiration) but respiration will continue to occur in the absence of oxgen by anaerobic respiration.
- Respiration involves a series of reactions
Describe an overview for cellular respiration
GLYCOLYSIS
- Where does it occur in the cell?
- Products of Glycolysis (3)
- Decribe what happens during glycolysis (7) - Include the products formed, enzymes used and fate of the ATP
- Cytoplasm
- 2 Pyruvate/ Pyruvic acid (3C), net gain of 2 ATP, 2NADH