Cellular Respiration Flashcards
ATP (Adenosine triphosphate)
It is a molecule for storing and releasing energy only when needed
- Powers reactions within the cell
- Is stored in bonds between phosphate groups
ATP in Living Systems
A living cell cannot store significant amounts of free energy
- Excess free energy would result in an increase of heat in the cell which effects the cell’s working and destroy it
ATP is used to prevent this from happening
Hydrolysis
A process that consist of releasing one or more phosphate groups from ATP
Definition of Glycolysis
The breakdown of glucose to release energy for use in cells
- Glycolysis takes place in the cytoplasm of most prokaryotic and all eukaryotic cells
- Glucose is found in foods
Glycolysis (5 Step Process)
S1 : ATP Start
S2 : EI → 2 ATP to 2 ADP
S3 : Glu → Fru
S4 : EG → D ADP to D ATP + 2 NADH+ to 2NADH
S5 : Pyruvate
During this process, the 6-carbon glucose molecule is split into two 3-carbon pyruvate molecules
Step 1 : 2 ATP is needed to start
Step 2 : During energy investment, 2 ATP become 2 ADP
Step 3 : Glucose is broken down into fructose 1,6-bisphosphate
Step 4 : During energy generation, double of 2 ADP create double of 2 ATP (resulting in 4 ATP) & 2 NAD+ convert into 2 NADH
Step 5 : The end result is the creation of 2 pyruvate molecules
pre-Citric Acid Cycle
Within mitochondria, pyruvic acid (the end product from glycolysis) is transformed into a two-carbon acetyl group that will be picked by a carrier compound called CoA
- This results in the creation of acetyl CoA.
Citric Acid Cycle (a.k.a. Krebs Cycle)
- Still occurs within mitochondria
- During this cycle, Acetyl CoA creates 2 ATP as well as NADH, FADH2 and carbon dioxide
Electron Transport Chain (ETC)
S1 : Electrons → pump hydrogen
S2 : Hydrogen diffuses → ATP Synthase → chemiosmosis
S3 : Oxygen → form water
Steps
Step 1 : Electrons from NADH and FADH2 are used to pump hydrogen across membrane, creating a gradient
Step 2 : As hydrogen diffuses back across the membrane through ATP Synthase, the movement converts ADP into ATP
Step 3 : Oxygen takes electrons and hydrogen and forms water (H2O)
Definition of Fermentation & Examples
Is a biochemical process that gets energy (ATP) from carbohydrates and does not require oxygen
Examples :
- Ethanol → wine
- Hydrogen → farts
- Lactid Acid → cheese
- Carbon dioxide → bread
Fermentation (Process)
Begins with G
- P → acet…
- Acet… → eth
- Carbon dioxide → fluid
Begins with glycolysis but there is an absence of O2
- Pyruvate is converted to acetaldehyde
- Acetaldehyde is then converted to ethanol
- The carbon dioxide molecules present can remain
suspended in fluid
Metabolic Pathways - Sugar
Sucrose and Fructose (monosaccharides) can be
broken down very similarly to glucose
Metabolic Pathways - Proteins
Proteins are processed by enzymes before breakdown or rather the removal of an amino group from amino acids
- The Amino groups result in ammonia that gets released as urea in mammals
Metabolic Pathways - Lipids
Cholesterol and triglycerides also use steps within
glycolysis pathways
- Lipids can be used for energy or hormone production
