Metabolism
Sum of all chemical reactions ina living thing/system |
Laws of Thermodynamics
#1 |
You can convert energy from one form to another (Ex. Carbohydrate is converted into ATP) |
#2 |
No transfer energy is a 10% efficient process (Ex. Converting carbohydrate to ATP is only 64% efficient) |
Entrophy
Measurement of randomness/disorder |
Increase entrophy |
Increase order = energy increases |
Decrease entrophy |
Increase disorder = energy decreases |
Gibb's Free Energy (G)
- Gives the potential of a system or a rxt tp do useful work
- G = H - (TS)
- H= Enthalpy (total energy)
- T = Temperature (in kelvin)
- S = Entropy
- When kelvin is 0, atoms do not move
- What the equation tells you:
1) Spontaneous system if G is negative, catabolic reaction (Ex. Cellular respiration)
2) Non-Spontaneous system if G is positive, anabolic reaction (Ex. Photosynthesis) |
G
Negative G |
Positive G |
Decrease energy |
Increase energy |
Increase entropy |
Decrease entropy |
Decrease temperature |
Increase temperature |
Spontaneous system |
Non-Spontaneous System |
Lose energy |
Convert energy |
Catabolic reaction (Cellular respiration) |
Anabolic reaction (Photosynthesis) |
ATP
Energy is released in ATP when a phosphate is broken off |
Metabolic Reactions
Catabolism |
Exergonic reaction (energy is released or lost), breaks down organic compounds, example: glycolysis |
Anabolism |
Endergonic reaction (energy is added), organic compounds are synthesized, example: photosynthesis |
Oxidation (Exergonic) |
Molecule loses an electron, H is formed |
Reduction (Endergonic) |
Molecule gains an electron (H) |
Coupled Reaction |
An exergonic reaction provides the energy for an endergonic reaction |
Electron Carriers |
NAD+/NADH, FADH+/FADH |
Chemiosmosis |
Movement of ions across a semipermeable membrane, examples: ETC |
Phosphorylation |
Adding a phosphate molecule |
Oxidative Phosphorylation |
Happens in the ETC, phosphate is added to ADP to form ATP |
Photophosphotylation |
Happens in photosynthesis, ATP is formed |
Substrate Phosphorylation |
Adds a phosphate, can still make ATP, occurs in glycolysis & krebs cycle |
|
|
Cellular Respiration
Aerobic Respiration |
Needs oxygen, consists of: glycolysis, krebs cycle, and the electron transport chain |
Anaerobic Respiration |
Oxygen is toxic, consists of: glycolysis, fermentation (lactic acid + alcoholic) |
Glycolysis |
In cytosol, oldest process |
Krebs Cycle |
In matrix of mitochondria |
Electron Transport Chain |
In cristae of mitochondria |
Problems with Glycolysis
Pyruvate is Toxic |
Solved with krebs cycle and/or fermentation |
NAD+ is in Short Supply |
Lack of NAD+ = process is not complete, solution is fermentation and/or the ETC |
Cost Analysis of Glycolysis
Overall Gains |
Net Gains |
4 ATP |
2 ATP |
2 NADH |
2 NADH (= 4 ATP) |
Krebs Cycle
Purpose |
Get rid of pyruvate from glycolysis |
Rules |
1) For every carbon to carbon bond that is broken, carbon dioxide is released and NADH is reduced |
2) For any rearrangement of the carbon chain molecule, the substrate order is as follows: NADH -> ATP -> FADH -> NADH |
Net Gains
Glycolysis |
Krebs Cycle |
2 ATP |
2 ATP |
2 NADH |
8 NADH |
| |
2 FADH |
Gains from 1 Glucose
Process |
Net Gains |
Net Gains in ATP |
Glycolysis |
2 ATP |
2 ATP |
| |
2 NADH |
4 ATP |
Krebs |
2 ATP |
2 ATP |
| |
8 NADH |
24 ATP |
| |
2 FADH |
4 ATP |
Total |
|
36 ATP |
|
|
Photosynthesis
- In chloroplast
- Anabolism (Small molecules become big), endergonic reaction (energy is added)
- Process of using light to split water, which provides ATP and NADH to fix carbon dioxide to 5 carbon RuBP to make 3 PGA (Phosoglyceral Aldehyde) |
Two Reactions
Light Rxt |
Occurs in thylakoid (individual pancakes of the chloroplast), needs water & sunlight, proces ATP and NADH |
Dark Rxt/Calvin Cycle |
In the stroma, needs ATP, NADH, and water, produces 3 PGA (Phosoglyceral Aldehyde) |
Reactions
Reaction |
Reactants |
Products |
Location |
Light Reaction |
Light, water, ADP, NADP+ |
Energy, oxygen, hydrogen, ATP, NADPH |
Thylakoid |
Dark Reaction, Calvin Cycle, C3 |
Carbon dioxide, ATP, NADPH |
3 PGA, ADP, NADP+ |
Stroma |
Photorespiration
- Peroxisomes & mitochondria rearrange and split a two carbon compound from the chlorpolast to release carbon dioxide
- Uses ATP |
C4 Pathway
- In grassplants
- Occurs in mesophyll cells above the bundle sheath cells lining vascular tissues
- Photorespiration: Oxygen is added, causes carbon dioxide to be released to the bundle sheath, needs PEP (Phosphoenolpyruvate Acid) |
Cost Analysis
C3 |
18 ATP, 12 NADH |
C4 |
...a lot of ATP |
CAM |
6-8 more ATP |
|
Created By
Metadata
Favourited By
Comments
No comments yet. Add yours below!
Add a Comment
Related Cheat Sheets
More Cheat Sheets by isabellagates