Cellular Respiration презентация

Metabolic reactions
Many reactions are involved in the metabolism of an organism:
ANABOLIC-CATABOLIC reactions
6CO2 + 6H2O + sunlight= C6H12O6 + 6O2
C6H12O6 + 6O2 = 6CO2 + 6H2O + Energy
HYDROLYSIS:
Cleavage (расщепление) of a complex molecule into its subunits by adding water
ex: maltose + H2O = glucose + glucose
DEHYDRATION:
Condensation reaction when from smaller molecules or subunits, complex molecule formed and water is released
ex: glucose + glucose = maltose + H2O

EXOTHERMIC:
When from reaction among products heat is released
ex: glucose + O2 = H2O + CO2 + energy + heat*
*this reaction passes in our muscles
ENDOTHERMIC:
When reaction needs heat energy and occurs by taking heat energy from environment
ex: evaporation of water in order to body to keep normal body temperature
REDOX reactions
OXYDATION:
When as a result of reaction some atom loses electron
ex: K=K++e-
REDUCTION:
When as a result of reaction atom accepts electron
ex: Cl2+2e-=2Cl-

Electron acceptors
NAD (Nicotinamide adenine dinucleotide), and FAD (Flavin adenine dinucleotide) are coenzymes present in all cells that transfer electrons during the redox reactions of metabolism.
NAD + H+ + 2e- = NADH
FAD + 2H+ + 2e- = FADH2

Cellular respiration
Cellular respiration is a kind of catabolism in which energy of food molecules, especially glucose is released as ATP and heat.
Oxygen in the air we breathe makes the production of ATP more efficient, although some ATP is made without oxygen.
Metabolic processes that require oxygen are called aerobic.
Metabolic processes that do not require oxygen are called anaerobic, which means “without air”.

Stages of cellular respiration
The breakdown of glucose during cellular respiration can be summarized by the following equation:
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
glucose oxygen gas carbon dioxide water ATP
Cellular respiration occurs in two stages:
Stage 1 Glucose is converted to pyruvate, producing a small amount of ATP and NADH.
Stage 2 When oxygen is present, pyruvate and NADH are used to make a large amount of ATP. When oxygen is not present, pyruvate is converted to either lactic acid or alcohol and carbon dioxide.

Cellular respiration

Stage 1: Breakdown of glucose - GLYCOLYSIS
The splitting of a glucose into 2 molecules of PYRUVATE is called glycolysis.
This step is the same in both aerobic and anaerobic respiration.
It takes place in cytoplasm.
Used:
Glucose molecule
2 ATP molecules
Produced:
2 molecules of pyruvate
4 ATP (net gain 2 ATP)
2 NADH are produced
ATP: 2, NADH: 2, FADH: 0

Stage 2: Production of ATP
When oxygen is present, pyruvate produced during glycolysis enters a mitochondrion and is converted to a two-carbon compound (Acetyl CoA).
This process is known as PYRUVATE OXIDATION
Used:
Pyruvate (*2)
Oxygen (*2)
Produced
Acetyl CoA (*2)
CO2 (*2)
1 NADH (*2)
ATP: 2, NADH: 4, FADH: 0

After Acetyl CoA is formed, it enters a series cyclic reactions called the KREBS CYCLE
It was discovered by Hans Krebs 1937, and in 1953 was given a Nobel prize
Used:
Acetyl CoA (*2)
Produced:
2 CO2 molecules (*2)
3 NADH molecules (*2)
1 FADH2 molecule (*2)
1 ATP molecule (*2)
ATP: 4, NADH: 10, FADH: 2
Stage 2: Production of ATP, continued

Electron transport chain
In aerobic respiration, electrons donated by NADH and FADH2 pass through an electron transport chain (ETC).
In eukaryotic cells, the electron transport chain is located in the inner membranes of mitochondria.
It is the highly organized system of enzymes and coenzymes
In here from each NADH molecule 3 ATPs are formed
3*10 NADH = 30 ATPs
And from each FADH2 molecule 2 ATPs are formed
2*2 FADH2 = 4 ATPs
The net gain of ATP produced in ETC is equal to 34 ATP
As a result of whole aerobic respiration, net 38 ATPs are produced
Stage 2: Production of ATP, continued

Electron Transport Chain of Aerobic Respiration

Catabolisation of different compounds

Respiration in the absence of oxygen
The process of energy formation from glucose molecule in absence of oxygen is called as FERMENTATION
In the absence of oxygen only glycolysis occur
Takes place only in cytoplasm
TYPES OF FERMENTATION
Lactic acid fermentation
Alcoholic fermentation

Lactic acid fermentation
Type of fermentation when only lactic acid formed with no CO2
Seen in some bacteria and in human body
Lactic acid fermentation is used in production of yoghurt and cheese
During heavy physical activities lactic acid fermentation is seen in muscles which causes muscle pain and stimulates brain to stop the activities.
REACTION OF LACTIC ACID FERMENTATION
C6H12O6 + 2ATP → 2C3H6O3 + 4ATP + heat
glucose lactic acid

Alcoholic fermentation
Type of fermentation when ethyl alcohol and CO2 are formed
Seen in some bacteria and in yeasts
Alcoholic fermentation is used in production of bread (yeasts), alcohol, wine, beer.
REACTION OF ALCOHOLIC FERMENTATION
C6H12O6 + 2ATP → 2C2H5OH + 2CO2 + 4ATP + heat
glucose ethyl alcohol carbon dioxide

Fermentation types

Production of ATP

Cellular respiration vs. Fermentation