Bio Quiz #3

Energy Definition

The ability to do work or bring about a change

Chemical Energy Definition

Energy stored in bonds

Mechanical Energy Definition

Energy of Movement

Kinetic Energy Definition

Energy of Motion

Potential Energy

Stored energy whose capacity is used to do work

First Law of Thermodynamics

Energy cannot be created or destroyed, but can be changed from one form to another

Second Law of Thermodynamics

Energy cannot be changed from one form to another without a loss of useable energy

• Cells are only capable of 40% efficiency, the remaining energy being given off as heat

Entropy Definition

Relative amount of disorganization in the universe

Every process that occurs in cells increases the entropy of the universe

Metabolism Definition

The sum of all chemical reactions that occur in a cell

• Reactants = Participate in the reaction

• Product = Produced by the reaction

What Increases the Entropy of the universe?

Spontaneous Reactions

Free Energy Definition

The amount of energy left to do work after a chemical reaction has occurred

• Reactions that have a negative Delta G occur Spontaneously

Exergonic Vs Endergonic

Exergonic Reactions Release energy

Endergonic Reactions require an input of energy to occur (Ex. Proteins and Carbohydrate Synthesis

Adenosine Triphosphate Cycle Steps

1. ATP is unstable and has high potential energy, when the Phosphate snaps off it creates energy

2. Exergonic Reaction. (Negative Delta G)

3. ADP is more stable and has lower potential energy than ATP and is combined with another Phosphate to make ATP

4. Endergonic Reaction to create ATP from ADP (Positive Delta G)

ATP Structure

Nitrogen Base

Ribose Sugar

Three Phosphate Groups

Reaction Coupling

Metabolic reactions that don’t occur spontaneously (Endergonic) can be coupled with and ATP breakdown reaction

How is ATP used in Coupling

ATP Hydrolysis can either energize the reactant or change the shape of a reactant

Function of Enzymes

A molecule that speeds up a chemical reaction

Are Enzymes used up in the Reaction?

Nope

Induced fit Model

The active site undergoes a slight shape change to accommodate substrates

How do Enzymes Work

They come in contact with substrates at the active site, and after the reaction has been completed the active site returns to its original state and can bind to another substrate

Activation Energy Definition

The energy that must be added to cause molecules to react with each other

What are some Factors that can influence enzyme rate

Substrate Availability

Temperature

pH

Presence of Inhibitors

Autotrophs vs Heterotrophs

Autotrophs make their own food (Plants)

Heterotrophs must take in preformed organic molecules (humans)

What is the role of NADP+/NADPH

Its a coenzyme (electron carrier) that’s needed to help reduce CO2 Molecules

2 Steps of Photosynthesis

Light Reactions

Calvin Cycle

Photosystem II Function

Absorbs light and sends high energy electrons down an electron transport chain (ETC)

Photosystem I Function

Electrons are passed to NADP+

Each NADP+ accepts two electrons and one H+ becoming NADPH

Why are plants green?

Because the pigments in the chloroplasts don’t absorb green light

How does the Electron Transport Chain Work (Photosynthesis)

Hydrogen Ions get pumped from the stroma into the thylakoid space and when H+ flows back down its concentration gradient, ATP is produced

Function of the Calvin Cycle

Plants take Carbon from CO2 Gas and “fix it” into the bonds of a carbohydrate molecule

Previously made ATP and NADPH are used to make carbohydrates (Glucose, Sugars, and Cellulose)

Where does the Calvin Cycle occur in the Cell

Stroma

Where does the Light Reactions occur in the Cell

Thylakoid

Catabolism

Breakdown of Molecules

Anabolism

Building Molecules

Glycolysis (Cellular Respiration) Where does it occur

Outside the Mitochondria

Function of Glycolysis

Glucose Molecules are split in 2 to make 2 Pyruvate Molecules

• Net gain of 2 ATP

Anaerobic Metabolism vs Aerobic Metabolism

Ana (Without Oxygen) Ex. Glycolysis

Aerobic Metabolism

Fermentation

Anaerobic Process

Net Gain 2 ATP

Pyruvate is turned into Lactate or Ethanol

Preparatory Reaction

1 Glycolysis into 2 Pyruvates

How is Pyruvate converted into Acetyl CoA

PDH

Where does the TCA Cycle take place

Mitochondrial Matrix

What does the TCA Cycle Produce

3 NADH, 1 FADH, 2 CO2 and 2 ATP

Where does the Electron Transport Chain take Place

Cristea

How is Oxygen used?

It is the final electron acceptor

Function of the ETC

Electron Carriers (FADH and NADH) hand off energy electrons which move down the chain to produce energy

How are hydrogen ions being used to produce ATP

ATP Synthase and Chemiosomic Gradients

1 Glucose makes how much Pyruvate?

2 Pyruvate

Goal of the TCA Cycle

To generate NADh and FADH to be used for the next step (ETC)

Goal of ETC

To enable the cell to convert NADH and FADH into Energy

1 NADH and 1 FADH = How much ATP?

1 NADH = 3 ATP

1 FADH = 2 ATP

How much ATP can 1 Glucose molecule make using the old Model

38 ATP

2 in the cytoplasm