AP BIO

What is an enzyme and what does it do?

A protein that speeds up a chemical reaction by lowering activation energy.

What is a substrate?

Molecule that binds to the active site (substrate = key).

What is an active site?

The place where the substrate binds (active site = lock).

What does the First Law of Thermodynamics state?

Energy cannot be created or destroyed.

What is the Second Law of Thermodynamics?

Entropy of the universe is always increasing.

What is activation energy?

Amount of energy required to start a reaction.

What is free energy?

Energy available to do a chemical process.

What is cellular respiration?

A series of reactions that convert glucose into ATP.

What is glycolysis?

The conversion of glucose to pyruvate/lactate and ATP (1st step).

What occurs during the Krebs Cycle?

A cycle of reactions that releases energy and activates electron carriers (2nd).

What is the link reaction?

A reaction that links pyruvate to coenzyme A (acetyl-CoA).

What is the electron transport chain?

Transports electron with electron carriers; the last electron acceptor is oxygen (3rd step).

What is a thylakoid?

Membranous sac (discs) in the chloroplast.

What is stroma in a chloroplast?

The fluid inside the chloroplast.

What is a granum?

The stacks of thylakoids.

What is photosynthesis?

The process of taking in CO2, light, and water to make glucose, oxygen, water, and ATP.

What is the function of chlorophyll?

Pigment that absorbs light energy.

What is the Calvin Cycle?

The dark reactions that make glucose/carbs.

What are the major environmental factors associated with enzymes?

Temperature, pH, concentration, salinity.

What is the difference between exergonic and endergonic reactions?

Exergonic - releases energy; Endergonic - absorbs energy.

Why is ATP considered an energetic molecule?

High-energy phosphate bonds (3 of them!).

Describe the process of glycolysis.

Break down glucose to get 2 pyruvates, 2 ATP; occurs in the cytoplasm.

Why are the first five steps of glycolysis known as the energy-gaining phase?

Because they are endergonic and require 2 ATP to be used.

Why are the final five steps of glycolysis known as the energy-releasing phase?

Because they are exergonic and form 4 ATP.

What are the end products of glycolysis in terms of molecules?

2 pyruvate, 2 ATP, 2 NADH.

What is the purpose of the link reaction and the Krebs Cycle?

To form more high-energy electron carriers (NADH and FADH2).

What are the end products of the Krebs Cycle?

2 FADH2, 6 NADH, 2 ATP.

Describe the electron transport chain.

Moves electrons and pumps H+ across the mitochondrial membrane, forming a concentration gradient.

How does ATP Synthase work?

Pumps H+ back across the membrane to form ATP (~32 ATP).

Where do the light-dependent reactions of photosynthesis occur?

Thylakoids; produces 12 ATP (3 per H+).

Is water or CO2 the primary reactant of the light reactions?

Water (2 H2O per cycle).

Where do the light-independent reactions of photosynthesis occur?

Stroma.

Is water or CO2 the primary reactant of the dark reactions?

CO2 (3 CO2 per cycle).

What is the overall yield of photosynthesis?

Photosynthesis yields glucose, oxygen, water, and ATP as products.