Bioenergetics Flashcards
(23 cards)
What are the four forms of energy?
Chemical
Electrical
Mechanical
Heat
What is chemical energy?
Energy stored in bonds of chemical compound.
What is electrical energy?
Energy resulting from flow of electric charge.
What is mechanical energy?
The sum of kinetic and potential energy.
ORGANIZED MOTION
What is heat energy? (aka molecular kinetic energy)
RANDOM atomic-molecular motion
The more heat you have the more kinetic energy you have.
What is free energy (G)?
The total amount of energy available to break and form other chemical bonds.
The energy available to do work in a system.
What is an endergonic reaction?
A reaction in which the energy of the products is greater than the energy of the reactants.
Energy must be supplied.
Delta G is positive
Ex. Photosynthesis
What is an exergonic reaction?
A reaction in which the energy of the products is lower than the energy of the reactants.
Energy is released.
SPONTANEOUS
Delta G is negative
ex. Cellular Respiration
What are the two ways the rate of a reaction can be increased?
Heating
A Catalyst
What three things make up and ATP?
3 phosphate groups
Ribose
Adenine
What is a calorie?
The heat required to change the temperature of one gram of substance by one degree Celsius
How many protons and electrons are donated to NAD+ when it’s reduced?
1 proton
2 (high energy) electrons
How is ATP made?
Cellular respiration
What are the three stages of cellular respiration?
Where do they occur?
Glycolysis
- cytosol
Citric Acid Cycle
- mitochondrial matrix
Oxidative Phosphorylation
- inner mitochondrial membrane
What are the products of glycolysis?
Net 2 ATP
2 NADH
2 Pyruvate
What is the gist of the citric acid cycle?
A pyruvate enters the mitochondrial matrix. 1 carbon is removed and CO2 exits the cycle. A hydrogen is transferred to NADH and exits the cycle.
The remaining combines to form Acetyl-CoA.
This enters the citric acid cycle by binding to oxaloacetate.
The cycle continues until oxaloacetate is reformed.
What is the key purpose of the citric acid cycle?
Hydrogens are bumped off and used for entry into the electron transport chain.
Also, high energy electron carriers are produced (NADH and FADH2)
What are the products of ONE TURN of the citric acid cycle?
3 - NADH
1 - FADH2
2 - CO2
1 - ATP
What is the final electron acceptor in the electron transport chain?
Molecular oxygen (that we breathe in)
O2- and H+ combine to make H2O
What are the two purposes of the long chain of electron carriers in the electron transport chain?
The high energy electrons release energy as they move through the chain. This energy is used to transport H+ across the inner membrane.
Also, by removing the energy, the oxygen can accept the electron, which drives the reactions. If The energy was still too high, the oxygen wouldn’t be able to bind to it.
How does ATP synthase work?
ATP synthase operates by creating a channel through which hydrogen can go down its concentration gradient back into the mitochondrial matrix. The energy released in doing so is used by ATP synthase to bind ADP to Pi
What is the net yield of cellular respiration?
2 ATP from glycolysis
2 ATP from the Citric Acid Cycle
34 ATP from oxidative phosphorylation
MINUS 2 ATP for shuttling NADH across mitochondrial membrane
= TOTAL ABOUT 36 ATP
How many ATP molecules are made in prokaryotes v eukaryotes?
Eukaryotes = 36 ATP
Prokaryotes = 38 ATP
