metabolism study guide Flashcards
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
What kinds and how many of each electron carriers have been reduced during the Krebs cycle?
3NADH, 1FADH₂
How many times does the Krebs cycle go around for one molecule of Glucose?
For one molecule of Glucose, there’ll be two rounds of Krebs cycle ( one for each acetyl coA).
Electrons are passed along a series of carrier molecules in a system called ______.
Electron transport chain (ETC).
In the ETC, ATP is made by _______ phosphorylation.
Oxidative
What term is used to describe the build up the hydrogen proton gradient on one side of the membrane?___________.
Chemiosmosis
The membrane in prokaryotes is the_____________.
Plasma membrane
The membrane in eukaryotes?
Mitochondrial inner membrane.
Name the enzyme that allows the protons to rush to the other sides.
ATP synthase
What is the final electron acceptor in aerobic respiration?
Oxygen
-Are there electron transport chains in anaerobic respiration?
-What does it use for a final electron acceptor?
-
-Sulfate, Nitrate, Bicarbonate.
Is there glycolysis in anaerobic respiration?
Yes, glycolysis is independent in both anaerobic and aerobic respiration.
What are the products of fermentation?
Ethanol
Lactic acid
Sometimes CO₂ and some acids
Examples of how fermentation is useful to humans
Carbs
The food we eat
Extending shelf life of foods…
Explain why humans and some bacteria and fungi are called chemoheterotrophs
Chemoheterotroph:derives its energy from chemicals/needs to consume other organisms in order to live.
Humans, bacteria, and fungi could be called chemoheterotrophs because they use organic carbon for their source of energy and for their main source of carbon
List the various reactions involved in the catabolism of a protein
Deamination, decarboxylation, dehyrdrogenation, organic acid
Protease breaks down polypeptides=lots of amino acids
Lastly they go to the Krebs Cycle
Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does C6H12O6 happen?
C6H12O6 happens in the beginning of Glycolysis.
Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 6O₂ happen?
6O₂ happens in the electron transport chain
Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 6CO₂ comes from?
6CO₂ comes from an intermediate step & Krebs Cycle.
Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 6H₂O occur?
6H₂O occurs at the end of ETC.
Respiration Reaction: Glucose reduced to Carbon Dioxide. Know where we find each one.
C6H12O6+6O₂=6CO₂+6H₂O+38ATP+Heat
Where does 38ATP occur?
38 ATP occurs in glycolysis, Krebs cycle, and ETC
