Unit 6 (copy)

What are the two primary factors that determine the fate of a chemical reaction?

Direction and Rate.

What is Kinetic Energy?

Energy associated with movement.

What is Potential Energy?

Energy that a substance/object possesses due to its structure and location.

List the types of energy used in biological processes.

Light, Heat, Mechanical, Chemical potential, and Electron/Ion Gradient

Light

Electromagnetic radiation visible to the eye, composed of photons.

Heat

Transfer of kinetic energy from one object to another.

Mechanical

Energy from an object due to its motion.

Chemical Potential

Potential energy stored in chemical bonds

Electron/Ion Gradient

Movement of charges creates energy and an electrochemical gradient.

What is the First Law of Thermodynamics?

Energy cannot be created or destroyed, only transferred or transformed.

What is the Second Law of Thermodynamics?

Energy transfers/transformation increase the disorder of the system, called entropy.

How does the change in free energy (delta G) determine the direction of a chemical reaction?

If delta G < 0 and delta G > 0

Define Activation Energy

The initial input of energy needed for the rearrangement of bonds before a reaction can occur.

What is the Transition State in a chemical reaction?

The state where original bonds stretch to create new products.

How do enzymes lower activation energy?

Straining reactants and positioning reactants close together

What is an Active Site?

The specific location on an enzyme where the chemical reaction takes place.

Define Substrate.

The reactant molecules that bind to an enzyme's active site.

What are Prosthetic Groups?

Small molecules that are permanently bonded to the surface of an enzyme, aiding in its function.

What are Cofactors?

Usually inorganic ions that temporarily bond to an enzyme's surface, promoting reactions.

What are coenzymes?

Organic molecules that temporarily bond to an enzyme.

List the three general ways metabolic pathways are regulated.

Gene Regulation, Cell-Signaling Pathways, and Biochemical Regulation

Gene Regulation

Enzymes are coded by genes that can be turned on/off.

Cell-Signaling Pathways

Cells adjust their metabolic pathways in response to environmental signals.

Biochemical Regulation

Noncovalent bonding of a molecule to an enzyme, known as Feedback Inhibition.

What is Cellular Respiration?

The process of metabolic reactions that cells use to obtain energy from organic molecules and release waste products.

What are the four stages of Cellular Respiration?

1. Glycolysis

2. Breakdown of Pyruvate

3. Citric Acid Cycle

4. Oxidative Phosphorylation

Summarize Glycolysis.

Glucose is broken down into 2 Pyruvate in the cytosol, producing 2 NADH, 4 ATP (net 2 ATP).

What happens during the Breakdown of Pyruvate?

2 Pyruvate are converted into 2 acetyl groups, producing one CO2 molecule, and occurs in the mitochondria.

Describe the Citric Acid Cycle.

Acetyl CoA is converted into 4 CO2, 6 NADH, 2 ATP, and 2 FADH2; regulated by the availability of substrates.

What is Oxidative Phosphorylation?

Process where NADH and FADH donate electrons to create an H+ electrochemical gradient, primarily through the electron transport chain.

What is the Energy Investment Phase in Glycolysis?

2 ATP are hydrolyzed into ADP and 2 phosphate groups, which attach to glucose to facilitate later reactions.

What role does ATP Synthase play in oxidative phosphorylation?

ATP is synthesized by ATP Synthase as H+ ions pass through, causing a spinning mechanism that generates ATP.

What are the two methods cells use to produce ATP in anaerobic environments?

Anaerobic Respiration and Fermentation

How does a lack of NAD+ affect glycolysis in anaerobic conditions?

An increase in NADH and a decrease in NAD+ disrupts the glycolysis process, making it difficult to continue ATP production.

Anaerobic Respiration

Some species utilize enzymes for oxidative phosphorylation without oxygen.

Fermentation

ATP is produced through glycolysis without requiring oxygen.