Metabolic Science Flashcards
What are the two key components of metabolism?
Anabolism & Catabolism
Give a definition of anabolism
Synthesis
Give a definition of catabolism
Degradation / Oxidation
Give a function of anabolism
Allows for Growth & Structure
Give a function of catabolism
Energy release, detoxification, re-synthesis
What is the overall generic reaction in the metabolism of food?
Cells release energy from food via a series of oxidation reactions
Explain oxidation reactions in reference to the metabolism of food
Food molecules act as electron donors (so undergo oxidation) and allows for a conformational change to the structure of the electron acceptor molecule to allow it to store energy
What molecules can store the energy released by oxidated food molecules
NAD & ADP (i.e. NADH and ATP)
Why is there a series of small oxidative reactions rather than one large one when it comes to food metabolism?
Performing smaller oxidative reactions allows for less energy to be ‘wasted’ / lost and more ATP / NADH molecules to be formed
What are the 3 key metabolic pathways
Glycolysis
Citric Acid Cycle
Oxidative Phosphorylation (not electron transport chain)
Where does glycolysis take place?
Cell Cytoplasm
What is the start and end products of glycolysis?
1 x 6 carbon glucose molecule
2 x 3 carbon pyruvate molecule
What are the energy inputs and outputs of glycolysis?
Input -> 2 ATPs
Output -> 4 ATPs, 2 NADH
How many steps are involved in glycolysis?
10 step process
What follows glycolysis?
Dependant on oxygen status
If in presence of oxygen the pyruvate can enter the mitochondrion and for a 2 carbon compound called Acetyl CoA (with the 3rd carbon binding with oxygen to form CO2)
If there is an absence of oxygen the pyruvate cannot bind to form CO2 so forms intermediate end products such as lactic acids
What is the products of pyruvate to acetyl CoA?
1 x CO2
1 x NADH
What is the 2nd step of metabolism?
Citric Acid Cycle
What is the start and end product of the citric acid cycle?
Acetyl CoA enters the citric acid cycle allowing for oxaloacetate to be converted to citric acid to restart the cycle
What is produced in the citric acid cycle?
2 x NADH
1 x FADH2
1 x GTP
What is the third step of metabolism?
Oxidative phosphorylation
What is the location of the 3rd step of metabolism
Electron Transport Chain
What is the electron transport chain?
A series of proteins and organic molecules found within the inner membrane of the mitochondria
What are the 4 key steps of oxidative phosphorylation & the electron transport chain?
Give a description of each step
Delivery of electrons via the reduced electron carriers (NADH and FADH2) to the molecules at the start of the chain.
Electron transfer and proton pumping: the electrons begin to be passed down the chain from a high concentration down to a low concentration. During this transition energy is released. The energy is harnessed by the proteins by pumping hydrogen ions from the inner matrix into the inter-membrane space causing an electrochemical gradient
Splitting oxygen to form water: to finish the transfer of electrons / give the electrons an end goal they bind to a O2 molecule & splits it to form H2O
Synthesis of ATP: when the electrons finish their transfer hydrogen ions can return to the matrix but as they pass through a particular protein which also acts as an enzyme called ATP-synthase - it is able to harness the energy and synthesise ATP
What is the name of the enzyme that forms ATP?
ATP-Synthase
