Cell Bio Lecture 3 Material

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