BMS 108 Ch. 5 Cell Metabolism and Respiration Flashcards
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What is the 2nd law of thermodynamics?
Energy transformation increases entropy.
What is the first law of thermodynamics?
Energy can only be transformed but cannot be created or destroyed.
What is entropy?
The degree of disorganization of a system
What is free energy?
Energy in an organized state that can be used to do work. In humans it’s ATP
What are some characteristics of Endergonic reactions?
- Energy required
- Anabolism (building big molecules)
- Product has more free energy than reactants
- e.g. making glycogen out of glucose
What are some characteristics of Exergonic reactions?
- Energy releasing
- Catabolism (breaking big molecules)
- Product has less energy than free energy
- e.g. hydrolyzing glycogen into glucose
Why do we continually need to take in new energy?
Cells require free energy input from the environment in order to buck entropy and remain highly organized.
Is catabolism an endorgonic or excergonic reaction? Is it more likely to use a hydrolysis or condensation reaction?
Exergonic; Hydrolysis
What is the difference between oxidation and reduction?
Oxidation = loss of electrons Reduction = gain of electrons
Oxidation and reduction are ALWAYS coupled reactions. They often involve transfers of hydrogen atoms instead of electrons.
What are the two coenzymes that play an important roles in carrying H?
NAD and FAD
Are FAD and NAD+ the oxidized form or reduced form on their respective enzymes?
Oxidized
How does NAD+ and FAD get to a reduced form that is ready to shuttle around electrons?
NAD+ + 2H = NADH + H+
FAD + 2H = FADH2
What is metabolism?
All reactions in the body that involve energy transformation.
All metabolism can be divided into two categories, what are they?
Catabolism: breaks down molecules and releases energy; primary source of energy for making ATP
Anabolism: makes larger molecules and requires energy; source of the body’s large energy-storage compounds
Define Glycolysis.
The metabolic pathway by which glucose is converted into 2 pyruvic acid (breaking sugar)
Other products: Net 2ATP and 2NADH
Exergonic, anaerobic
Before glycolysis can happen, glucose must be activated by 2 ATP. This process also traps the glucose molecule inside the cell. What is this process called?
Phosphoralation
*Phosphoralated organic molecules cannot cross the plasma cell membrane.
In order for glycolysis to continue, NAD+ needs to be refreshed. The NADHs produced in the initial glycolysis phase need to give away Hs. What is this pathway called?
Lactic Acid Pathway
Is NAD reduced or oxidized during glycolysis? During anaerobic respiration? Why?
Reduced; Oxidized; In order for glycolysis to continue
How does lactic acid form?
In absence of O2, NADH (reduced form) gives its Hs to pyruvic acid forming lactic acid and NAD (oxidized form)
Glycolysis + lactic acid pathway = ?
anaerobic metabolism