metabolism study guide Flashcards
(44 cards)
Every cell acquires _________.
nutrients
Cellular energy is stored in ________.
ATP (Adenosine Triphosphate)
Precursor Metabolite:
products in catabolic pathways & used for raw materials for anabolic pathways
Catabolism:
All decomposition reactions in a living organism; the BREAKDOWN of complex organic molecules into simpler ones.
(think of a CATaboilism BREAKING DOWN all the glass in your house).
Anabolism:
All SYNTHESIS reactions in a living organism, the BUILDING of complex organic componds into simpler ones.
Metabolic pathway:
A sequence of enzymatically catalyzed reactions occuring in a cell. (End product)
Activation energy
The minimum collision energy required for a chemical reaction to occur.
remember: ENZYMES reduce amount of activation energy
Amphibolic pathway:
A pathway that is both anabolic and catabolic.
Substrate:
A compund with which and enzyme reacts or acts up.
In a redox reaction, which is being reduced?
-electron donor
-recipient
Oxidation
Is
Lost
Reduction
Is
Gained
-Electron donor (becomes oxidized)
-Electron acceptor (becomes reduced)
-Biological catalysts are called __________.
-What are the componets of this catalyst?
-Enzyme
-Components of enzyme:
—apoenzyme (protein portion)
—cofactor (non protein portion, aka coenzyme)
apoenzyme+cofactor create the holoenzyme
What are other characteristics of this catalyst (enzyme): can be used more than once
-specific for a substrate → products
-speeds up reactions (catalyst)
-they are not permanently changed in the reaction.
-lowers activation energies(→amount of energy it takes to start a reaction).
What are some environmental or physical factors that influence enzyme activity? explain.
- Temperature (enzyme activity decreases). optimalmeaining if its too cold→ it may not operate. if its too high →it could be disturbed.
- pH (denatures enzymes) most operate at pH 7.
- Enzyme and substrate concentrations
- Presence of inhibitors
What are some chemical factors that can inhibit enzyme activity?
-competitive inhibitors
-non competitive or allosteric inhibitors
-too much product
PHYSICAL FACTOR: substrate concentration
What is phosphorylation? What types are there?
Phosphorylation: the addition of a phosphate group to an organic molecule.
Types:
1.Substrate-level phosphorylation (taken from molecules)
2. Oxidative phosphorylation (happens at the end of cellular respiration)
3. Photosphorylation-happens in photosynthesis→ETC, creation of a proton gradient, harvesting energy of the proton gradient by making ATP.
What type of phosphorylation occurs in glycolysis?
Substrate-level phosphorylation (also occurs in Krebs Cycle)
What type of phosphorylation occurs in the Electron Transport Chain (ETC)?
2 parts: occurs in oxidative phosphorylation and chemiosmosis.
TRUE or FALSE:
Glycolysis is driven by the presence of oxygen.
FALSE
-glycolysis is an anaerobic process, produces minimal amount of ATP.
On the other hand……
Krebs Cycle & ETC do need oxygen to proceed, and in presence of oxygen, these processes produce much more ATP than glycolysis alone.
How many ATPs are formed from Glycolysis?
4 ATP.
What is the net gain of ATP?
Only 2(basically paying off debts)
What are all products of glycolysis?
2 pyruvic acid + 2ATP +2NADH +2H
What product of the intermediate step enters the Krebs Cycle?
2 molecules of acetyl-coA
___ molecules of ATP are made in the Krebs cycle by ___________ phosphorylation.
1 molecule
Sub-level phosphorylation
What waste product is given off as the organic acids become decarboxylated?
CO₂
