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What do enzymes do?
Catalyze and control chemical reactions in cells
What are the two pathways for metabolism?
Catabolic and anabolic
What does catabolism do?
Breaks down larger molecules into smaller molecules, generating useful energy
What does anabolism do?
Uses energy from catabolism to drive synthesis of useful molecules
What does the 2nd law of thermodynamics say?
Randomness increases in nature (entropy)
What does the 1st law of thermodynamics state?
Energy cannot be created nor destroyed, but it can be converted from one form to another
What is photosynthesis?
Organic molecules being produced by energy from the sun
What is the order of photosynthesis
Electromagnetic (light) energy → High-energy electrons → chemical-bond energy
What happens during stage 1 of photosynthesis?
Capture of light energy in which light and water make oxygen
What occurs in stage 2 of photosynthesis?
Manufacture of sugars in which water and CO2 created sugar
How do cells breakdown sugars and other organic molecules?
Oxidizing them producing CO2 and H2O
What is the process of sugar breakdown, creating carbon dioxide and water
Respiration
What completes the cycle of life?
Balancing reactions of photosynthesis and respiration
When does oxidation occur?
When electrons are transferred between atoms, specifically when electrons are removed
When does reduction occur?
When electrons are added to an atom
How are chemicals with high energy chemical bonds broken down?
When activated by an input of energy
What to enzymes do to chemical reactions?
Lower activation energy required to perform the chemical reaction
Catalysts are _______ by participating in the chemical reaction?
Unchanged
What is free energy/G?
Useful energy in a system
What is the change in free energy or ΔG?
The amount of free energy that is changed by the reaction
To be an energetically favorable reaction, the ΔG must be what?
Negative
When can an energetically unfavorable reaction occur?
When coupled to an energetically favorable reaction with a sufficiently negative ΔG that counteracts the positive ΔG
What is the state of equilibrium?
When the forward and reverse reactions are equal
Is equilibrium maintained in cells?
No , due to a constant flux of substrates, products, and metabolism
How can the equilibrium constant be calculated?
K=Concentration of Products / Concentration of Substrate
How is ΔG° calculated?
ΔG°=-5.94log10(K)
When chemical reactions reach a steady state and products and reactants balance, ΔG=?
0
The higher the equilibrium constant, the ________ ΔG° ?
Lower
What can be used to determine the strength of molecular interactions?
The equilibrium reaction
Association rate is equal to what?
k_on [A][B]
Dissociation rate is equal to what?
k_off [AB]
In metabolic pathways, what are often coupled?
Sequential reactions
The ΔGs for sequential reactions are what?
Additive
Sequential reaction ΔGs being additive allows for what?
An unfavorable reaction to be performed when coupled to a favorable reaction
How are complex molecules made from less complex precursors?
Energy in the form of carrier molecules are used
What are examples of carrier molecules?
ATP and NADPH
What is the most commonly used energy carrier molecule?
ATP
How is ATP produced?
From energy from the sun or food molecules
What is ATP used for?
Work in the cell
Molecules like NADH and NADPH have what type of energy?
Reducing energy
NADP+ undergoes reduction to create?
NADPH
NADPH undergoes oxidation to create?
NADP+
What are examples of biopolymers?
Nucleic acids, proteins, and polysaccharides
What is the polymerization of nucleic acids driven by?
2 coupled reactions that provide more energy that is needed in this synthesis
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