Enzymes
What is the function of an enzyme?
To catalyze a chemical reaction
How does changing the structure of an enzyme affect that enzyme?
It changes the function of the enzyme and often disables it
What is glycolysis?
The oxidation (loss of electrons) of glucose to pyruvate
Where does the energy that fuels photosynthesis come from?
The sun
What is an exergonic reaction?
Net release of free energy into the surroundings
How does an enzyme affect the rate of biological reactions?
It speeds them up by lowering the activation energy
What organisms first evolved photosynthesis?
cyanobacteria
Where does the citric acid (Krebs) cycle take place?
The mitochondrial matrix
Where are chlorophyll located?
Chloroplasts, specifically in photosystems in the thylakoid membrane.
How are cellular processes powered?
Free energy movement through metabolic pathways
What two conditions affect the structure of an enzyme?
Temperature and pH
How does variation at the molecular level impact fitness?
Variation at the molecular level allows organisms flexibility to respond to environmental stimuli.
How are electrons transported to the electron transport chain in cellular respiration?
Via the molecules FADH and NADH
From the stroma into the thylakoid interior
How is entropy maintained in a system?
Organisms create ordered structures from less organized systems
What is a competitive inhibitor?
A molecule that mimics the substrate competing for occupying the active site of the enzyme
What is one piece of evidence that supports atmospheric oxygenation by cyanobacteria?
A layer of iron ore rust
What is the final electron acceptor in the electron transport chain used in aerobic respiration?
Oxygen
What is the relationship between the photosystem and the electron transport chain?
Photosystems have chlorophyll which energize the electrons that move through the electron transport chain.
What are the first two laws of thermodynamics?
1 - Energy is neither created nor destroyed
2 - Every energy transfer increases entropy in the universe
Is Gibbs free energy changed in enzyme catalyzed reactions?
Enzymes do not affect Gibbs free energy of a reaction. This means that they do not increase or decrease the number of products and reactants.
Give one example of a protein that is reversable after denaturation.
insulin
Identify the three locations of the electron transport chain
Thylakoid membrane (photosynthesis), inner mitochondrial membrane (eukaryotic respiration), plasma membrane (prokaryotic respiration)
How is ATP synthesized in light dependent reactions?
ATP synthase via proton motive gradient
What is energy coupling?