Unit 3 Class Notes

Cellular Respiration, Fermentation, and Photosynthesis

Cellular Respiration: Inputs

• 6O₂

• C₆H₁₂O₆

Cellular Respiration: Outputs

• CO₂

• H₂O

• ~ 34 ATP

Glycolysis: Inputs

• C₆H₁₂O₆

• 2NAD+

• 2 ATP

Glycolysis: Outputs

• 2 pyruvate acids

• 2 NADH

• 4 ATP

Glycolysis: Location

Cytosol

Glycolysis: Aerobic or anaerobic?

Anaerobic

Cellular Respiration: Location

Mitochondria

Pyruvate Oxidation: Location

Mitochondrial Matrix

Pyruvate Oxidation: Aerobic or Anaerobic

Aerobic

Pyruvate Oxidation: Inputs

• 2 pyruvate acids

• 2 NAD+

Pyruvate Oxidation: Outputs

• 2CO₂

• 2 NADH

• 2 acetyl acids

Kreb’s Cycle: Location

Mitochondrial matrix

Kreb’s Cycle: Aerobic or Anaerobic

Aerobic

Kreb’s Cycle: Inputs

• 2 acetyl acids

• 6 NAD+

• 2 FAD+

Kreb’s Cycle: Outputs

• 4CO₂

• 6 NADH

• 2 FADH₂

• 2 ATP

Electron Transport Chain: Location

Mitochondrial Inner Membrane

Electron Transport Chain: Aerobic or Anaerobic

Aerobic

Electron Transport Chain: Inputs

• 6O₂

• (10) NADH

• (2) FADH

• ADP+P

Electron Transport Chain: Outputs

• FAD+

• NAD+

• 6H₂O

• ~24 ATP

Photosynthesis: Location

Chloroplast

Photosynthesis: Inputs

• light

• 6H₂O

• 6CO₂

Photosynthesis: Outputs

• 6O₂

• C₆H₁₂O₆

Light Dependent Reaction: Location

Thylakoid

Light Dependent Reaction: Inputs

• Light

• ADP+P

• 6H₂O

• NADP+

Light Dependent Reaction: Outputs

• O₂

• NADPH

• ATP

Calvin Cycle: Location

Stroma

Calvin Cycle: Inputs

• NADPH

• H₂O

• O₂

Calvin Cycle: Outputs

• NADP+

• C₆H₁₂O₆

• ADP+P

Fermentation: Location

Cytosol

Fermentation: Inputs

• C₆H₁₂O₆

• 2 ADP+P

Fermentation: Outputs

• (Lactate acid) or (ethanol and CO₂) or ( acetic acid)

• 2 ATP

What is Feedback Inhibition?

when the products of an enzyme reaction become an inhibitor for an enzyme earlier in the pathway

How does concentration effect enzyme function?

an optimal amount of enzyme is “saturated” when as soon as a product is released a new substrate binds to the active site (“saturation” is the max efficiency rate of an enzyme)

What is NAD+/NADH?

• nicotinamide adenine dinucleotide

• coenzymes- carries electrons (H+)

• derived from niacin (B vitamins)

What is FAD+/FADH₂?

• flavin adenine dinucleotide

• coenzymes-carried 2 electrons (H+)

• derived from riboflavin (vitamin B3)

What is Pyruvate Oxidation controlled by?

pyruvate dehydrogenase enzyme complex

What is an enzyme complex?

2 or more enzymes that work together (switched on and off based on assembled parts

How does the environment effect enzyme function?

every enzyme can function in a range of pH and temperature, but all have an optimal state when they are most effective

What is the main definition of glycolysis?

the creation of pyruvic acid from glucose that starts the glucose metabolism

What is the definition of cellular respiration?

the process of breaking down glucose, which creates ATP as a byproduct

Chemical formula for cellular respiration

C₆H₁₂O₆+6O₂→6CO₂+6H₂O

ADP+P —^→ATP

What is ATP?

adenosine triphosphate

What are cofactors and coenzymes?

(not proteins) molecules that bind to enzymes and activate their function (not active site though)

• cofactor-inorganic

  • coenzyme-organic macromolecule (not protein)

What does phosphoralated mean?

adding a phosphate (PO₃) to something (ADP→ATP)

What does it mean to be protonated?

a proton is added to something (NAD+→NADH)

What are the 4 processes of cellular respiration in order?

1. glycolysis

2. pyruvate oxidation

   1. Kreb’s cycle

3. electron transport chain

What are the 3 steps in the Kreb’s Cycle?

1. acetyl CoA & oxalacetric acid react to make citric acid

2. citric acid is broken down by the remaining CO₂ (protonating NAD+)

   1. citric acid fully converted back to oxalacetric acid causing the protonization of NAD+/FAD+ and the production of 1 ATP

What are each of the electrons and protons in the electron transport system converted to or used for?

• NADH→NAD+ & H+ & e-

• FADH₂→FAD+ & 2H+ & 2e-

• e- → activate membrane proteins

  • H+→move through activated proteins

What is the definition of the Kreb’s cycle?

a series of reactions that break down citric acid to release stored energy

What are the 2 ways cells can make ATP without O₂?

• anaerobic cellular respiration

• fermentation

What does anaerobic cellular respiration use? What cells do this?

uses sulfur, sulfate, or nitrate as election receptors

some bacteria & archaea that live in low 0₂ environments

What process does fermentation use to produce ATP?

glycolysis

How is lactic acid made in fermentation?

NADH transfers electrons to the pyruvate acid while makes lactic acid

How is ethanol and CO₂ made in fermentation?

CO₂ broken off the pyruvate, NADH transfers electrons to remaining molecule to make ethanol

What is the definition of photosynthesis?

conversion of light energy into chemical energy

What is the chemical formula for photosynthesis?

6CO₂+6H₂O→C₆H₁₂O₆+6O₂

Where and what is the thylakoid?

inside the mitochondria

a single membrane disk

Where and what is the granum?

inside the mitochondria

a stack of several thylakoids

Where and what is lumen?

the space inside a thylakoid

Where and what is stroma?

inside the mitochondria

the solution surrounding the thylakoids and granum

How many membranes does mitochondria have? (and why?)

2 membranes (endosymbiosis theory)

What is the first step of light dependent reactions?

a photon of light hits photosystem 2 (P680)

• PS2 absorbs light energy & uses H+ to energize an election to the higher energy level

• electron leaves PS2 & is replaced by electrons from H₂O

  • broken apart into H+ and O

What is the first step of light dependent reactions?

high energy electron is passed to cytochrome C which pumps H+ into the thylakoid (lumen) from the stroma

What is the third step of light dependent reactions?

hydrogen passes through ATP synthase which phosphorylates ATP (chemiosmosis)

What is the fourth step of light dependent reactions?

electron lost energy @ cytochrome C so it is passed to PS1 (or P700) which absorbs a proton of light & re-exciting the electron