Chapters 8+9 - Energy and Enzymes: An Introduction to Metabolic Pathways/Cellular respiration and Fermentation Flashcards
what are the 4 components/steps of cellular respiration?
- glycolysis
- pyruvate processing
- the citric acid cycle
- electron transport and chemiosmosis
enthalpy
total energy in a molecule (includes potential/heat/volume/pressure)
energetic coupling
-allows chemical energy released from one reaction to drive another reaction
reduction-oxidation reaction (redox reactions)
chemical reactions that involve the loss/gain of one or more electrons
-reduction and oxidation go hand in hand (one loses electrons, another gains)
when is a molecule/atom considered “oxidized”?
when it has lost one or more electrons (and protons that follow)
-lower potential energy
when is a molecule/atom considered “reduced”?
when it has gained one or more electrons (and protons that follow)
-higher potential energy
what is an easy trick to identifying where redox reactions have occurred?
- follow the hydrogen atoms
- reduction adds “H”
- oxidation removes “H”
how does ATP work?
-works by phosphorylating (transferring a phosphate group) target molecules
how does ATP hydrolysis release free energy?
- when ATP reacts with water during hydrolysis, the bond between ATP phosphate group and its neighbor is broken
- this releases free energy
kilocalorie (kcal)
unit of measure
-amount of energy needed to raise 1kg of water by 1 degree celcius
why is ATP high energy?
the four negative charges in its 3 phosphate groups repel each other
-when hydrolized, entropy of products is higher than that of the reactants
what is the structure of ATP? what does it consist of?
- phosphate groups
- ribose
- adenine
phosphorylation
the addition of a phosphate group to a protein
where does the energy released from ATP usually go?
usually transfers to a protein and changes the proteins shape
nicotinamide adenine dinucleotide (NAD)
- reduced to form NAHD
- NAHD readily donates electrons to other molecules
- considered an electron carrier
- has “reducing power”
what happens when glucose is oxidized?
- carbon atoms = oxidized to form carbon dioxide
- oxygen atoms = reduced to form water
what do organisms use glucose for?
- build fats/carbs/other compounds
- make ATP through cellular respiration or fermentation
what is a crucial difference between cellular respiration and fermentation?
cellular respiration uses oxygen
fermentation occurs without oxygen
cellular respiration
any suite of reactions that produces ATP in an electron transport chain
cellular respiration step 1
glycolysis
- glucose is broken down to pyruvate through 10 reactions
- includes energy investment phase/energy payoff phase
cellular respiration step 2
pyruvate processing
-pyruvate is oxidized to form acetyl CoA
cellular respiration step 3
citric acid cycle
-acetyl CoA is oxidized to CO2
cellular respiration step 4
electron transport and chemiosmosis
- compounds that were reduced in steps 1-3 are oxidized
- produces ATP
feedback inhibition
occurs when an enzyme in a pathway is inhibited by a product of that pathway
*can be done to stop production of ATP when there is an abundance, save energy
what happens to pyruvate produced during glycolysis?
-transported from cytosol to mitochondria
mitochondria characteristics
have inner and outer membranes
- cristae (sac like structures inside)
- mitochondrial matrix (inside inner membrane outside of cristae)
