Biology 20-1 Unit C Cellular Respiration

Obligate anaerobes

Can’t survive in the presence of oxygen

Facultative anaerobes

Normally aerobic, but can switch to anaerobic without any negative effects

Gas exchange

The exchange of gases that are needed for cellular respiration

Examples of facultative anaerobes

Yeast, bacterias like E. Coli

Obligate aerobes

Organisms that cannot survive without oxygen and relies on aerobic respiration to produce ATP

Cellular respiration

The controlled release of energy by breaking down organic compounds to produce ATP

ATP

A nucleotide that has a 5 carbon sugar, a nitrogenous base, and 3 phosphate groups

Adenine

Nitrogenous base

Coenzymes

A non protein organic compound that facilitates enzyme reactions by cycling between a loaded and unloaded form

ATP coenzyme

The loaded form that transfers chemical energy to enzymes and allows the activation threshold to be reached

Exergonic reaction

Reaction is spontaneous

Endergonic reaction

Reaction is not spontaneous

ATP hydrolysis

Releases the third phosphate which converts the coenzyme into its unloaded form, ADP

Life processes that use ATP

Movement, active transport, biosynthesis

ATP for movement

Cell division, muscle contraction, organelle movement, beating cilia or flagella

ATP for active transport

Moves materials against their concentration gradient, endocytosis, exocytosis, biosynthesis

Cytosis

The process in which a cell transports material in or out using membrane bound vesicles

ATP for Biosynthesis

The assembly of macromolecules such as protein synthesis, DNA replication

Hydrogen and Electron Carriers

Coenzymes that act as a transitional energy carrier which can indirectly transfer energy to form ATP

oxidative phosphorylation

The process of producing ATP in the presence of O2

2 Hydrogen/Electron Carriers and reduced forms

NAD, FAD, NADH, FADH2

Reduction

The gain of electrons/hydrogen or the loss of oxygen

Oxidation

The loss of electrons/hydrogen or the gain of oxygen

Cellular respiration starts off with a high energy substance and ends with low energy products

Glucose to H2O and CO2

The higher the energy activity

The higher number of mitochondria

Parts of the Mitochondria

Inner and outer membrane, Cristae, Matrix, intermembrane space

Mitchondria Cristae

ETC and ATP synthesis happens here, increases surface area

Mitchondria Matrix

location of Krebs or Citric acid cycle

Intermembrane space

H+ accumulate to provide a gradient for ATP synthesis

Processes in Aerobic Cellular Respiration

Glycolysis, Krebs cycle, Link Reaction, Hydrogen transfer system (ETC)

Location of Glycolysis

In the cytosol of the cell

Location of the ETC

In the inner mitochondrial membrane

Glycolysis

Glucose reacts with 2 ATP with the help of hexokinase and phosphofructokinase, creating Fructose 1, 6-bisphosphate, which splits into 2 PGAL, which turns into 2 PGA after the 2 H+ goes to the 2 NAD creating 2 NADH, which then turns into 2 Pyruvate after the Pi combines with the 4 ADP forming 4 ATP

Gains of Glycolysis

4 ATP, NADH

Losses of Glycolysis

2 ATP

hexokinase

An enzyme that helps add the first phosphate during glycolysis

phosphofructokinase

An enzyme that helps add the second phosphate during glycolysis

Fructose 1, 6-bisphosphate

6 Carbon molecules and 2 phosphates

Link Reaction

2 Pyruvate loses 2 CO2and during oxidation, the 2 NAD accepts the e- and 2 H+, forming 2 NADH, forming Acetic acid. Then the Acetyl groups combine with CoA to form Acetyl CoA

Gains of Link reaction

2 NADH

Losses of Link reaction

2 CO2

Acetyl Group

2 carbon molecule

Krebs Cycle

1 Acetyl CoA transfers its acetyl group to combine with oxaloacetate, creating citrate while the CoA is reused in the Link reaction. NAD and FAD accept electrons and H+, turning into 3 NADH and FADH2, Decarboxylation releases 2 CO2.

Gains of Krebs cycle

6 NADH, 2 ATP, 2 FADH2

Losses of Krebs Cycle

4 CO2

Citrate / Citric Acid

6 carbon compound

Electron Transport Chain

All of the NADH and FADH2 from glycolysis, the link reaction, and the krebs cycle takes its electrons to the ETC in the inner mitochondrial membrane and cristae. The ETC releases the energy in the hydrogen/electron carriers to make ATP by oxidative phosphorylation

ATP to ATP

1 to 1

NADH to ATP

1 to 3

FADH2 to ATP

1 to 2

Net Total ATP from Aerobic Cellular Respiration

36 ATP, other 2 is used to move pyravate into the matrix

Processes of Oxidative Phosphorylation

Proton motive force, chemiosmosis, reduction of oxygen

Proton motive force

NADH and FADH2 are oxidized and release high energy e- and H+. as e- moves down the ETC, H+ is pumped from the matrix into the intermembrane space, which forms a electrochemical gradient

Chemiosmosis

H+ moves down the electrochemical gradient, diffusing back into the matrix, and as H+ move through the ATP synthase, they rotate the enzyme making ATP

Reduction of Oxygen

Oxygen as the final electron acceptor, binds with the electrons and H+ to make water.

Other molecules used for energy

lipids, proteins

Lipids

Long term and easy to store energy that can enter the krebs cycle

Protein

Amino acids can be absorbed by glycolysis, link reaction, and krebs cycle.

Anaerobic Cellular Respiration

Glycolysis, Lactic acid or alcohol fermentation

Fermentation

The conversion of pyruvate into an alternative carbon compound while oxidizing the NADH, which regenerates some NAD needed for Glycolysis

Alcohol Fermentation

2 Pyruvate is converted to 2 Acetaldehyde, which is converted to 2 Ethanol

Acetaldehyde

A compound that forms after 1 CO2 is removed from pyruvate

Ethanol

A compound that forms after the NADH from glycolysis gives their H+ to acetaldehyde

Lactic Acid fermentation

2 NADH gives 2 H+ to 2 Pyruvate, converting it to 2 Lactate

Net total ATP for Anaerobic cellular respiration

2 ATP, other 2 ATP used for glycolysis

5 Factors affecting the rate of cellular respiration

Temperature, pH, Inhibitors, Glucose availability, oxygen availability

Best temperature for Cellular respiration

37 degrees celsius

Low temperature for cellular respiratoin

Not enough kinetic energy for collisions of molecules, which means less reactions

High temperature for Cellular respiration

Enzymes denature and lose functionality

Best pH for cellular respiration

pH of 7

High or low pH for Cellular respiration

Enzymes denature and lose reaction rate

Inhibitors affecting cellular respiration

Disrupts the normal reaction pathway

Types of Inhibitors affecting cellular respiration

Competitive inhibitors, Non competitive inhibitors

Competitive inhibitors affecting cellular respiration

Binds directly to the active site on the enzyme, preventing reaction

Non competitive inhibitors

Binds to a site other than the active site to prevent substrate interaction

Examples of competitive and non competitive inhibitors

Citrate competes with acetyl CoA, Cynade binds to Electron transporter, preventing the movement of e- in ETC

More glucose in cellular respiration

Results in higher rates of cellular respiration until glycolytic enzymes are saturated

Low oxygen in cellular respiration

Results in low rates of respiration

No oxygen in cellular respiration

Results in anaerobic respiration

Respirometer

Determines an organism’s aerobic respiration rate by measuring oxygen consumption

A way to measure O2 consumption

Measuring the change in pressure of the system when the CO2 that is produced is absorbed by an alkali