Chapter 5 Flashcards
Metabolism is broken down into what two components?
- Anabolism (synthesis)
2.Catabolism (decomposition)
new components (AKA biosynthesis)
synthesis
Energy production of nutrients to harvest energy
ATP PRODUCTION
Reactions that break down complex molecules
Catabolism
The total sum of chemical reactions of
biosynthesis and energy-harvesting is
termed
metabolism
Metabolic pathways employ 4 critical components to complete processes, what are they?
- ATP
- Enzymes
- Chemical energy source
- Electron carriers
Catabolism has what type of reactions?
Hydrolysis
Is catabolism or anabolism exergonic?
Catabolism
Reactions involved in the synthesis of cell components
Anabolism
Which type of reactions of metabolism require energy?
anabolic reactions
Which reactions involve dehydration synthesis?
Anabolism
name the metabolic pathways:
___________: starting compound leads to one end product
__________: starting compound branches out to form more than 1 end product
______________: starting compound follows a cycle to lead to one end product
- Linear Metabolic Pathway
- Branched Metabolic Pathway
- Cyclical Metabolic Pathway
What is known as the energy currency of the cell?
ATP
substrate phosphorylation uses what type of energy to add phosphate ion to molecule of ADP?
chemical energy
ATP is created by what three mechanisms?
- Substrate phosphorylation
- Oxidative phosphorylation
- Photophosphorylation
What are the components of ATP?
Nitrogen source (Adenine)—–Sugar (Ribose)——Phosphate group (3 negatively charged ions)
___________ phosphorylation uses energy from proton motive force to add
phosphate ion to ADP
oxidative phosphorylation
Define Collision Theory
chemical reactions occur when atoms, ions, and molecules collide
What is the collision energy required for a chemical reaction to occur
Activation Energy
which ATP formation utilizes radiant energy from sun to convert phosphorylate
ADP to ATP
photophosphorylation
T/F Reaction rate is the frequency of collisions containing enough energy to bring about a reaction
TRUE
proteins that act as biological catalysts and accelerate the conversion of substrate to product
enzymes
What 4 things increase reaction rates?
- enzymes
- increasing temp
- increasing pressure
- increasing concentration
How do you catalyze reactions?
by lowering activation energy
T/F Enzymes have specificity for particular substrates
TRUE
what is activation energy (A.E.)
Energy required to initiate a chemical reaction
catalysts ________ the rate
of a chemical reaction without becoming part of the products or being consumed in
the reaction
increase
T or F Enzymes cause the chemical reaction
False, enzymes do not cause the reaction they just facilitate it without being altered
Fill in the blank (mechanism of enzymatic action):
- Substrate contacts the enzyme’s active site to form ________-_______ complex
- Substrate is transformed and rearranged into ______, which are released from the enzyme
- Enzyme is __________ and can react with other substrates
1.enzyme–substrate complex
- products
- unchanged
The number of substrate
molecules an enzyme converts to a product per second
Turnover number
– Generally 1 to 10,000
– Can be as high as 500,000
name the components of holoenzyme: (Cofactor, Holoenzyme, Coenzyme, Apoenzyme)
_____________: protein portion (inactive when alone)
_________: non-protein component (e.g. Fe, Zn etc.)
__________: organic cofactor
(e.g. NADH)
__________: whole, active
enzyme form
- Apoenzyme
- Cofactor
- Coenzyme
- Holoenzyme
what suffix do enzymes typically end with?
-ase (lyase, isomerase, ligase, etc.)
Coenzymes are ________ ________that assist enzymes by serving as electron carriers
organic cofactors
What 4 coenzymes assist enzymes by serving as electron carriers?
- Nicotinamide adenine dinucleotide (NAD+)
- Nicotinamide adenine dinucleotide phosphate (NADP+)
- Flavin adenine dinucleotide (FAD+)
- Coenzyme A
Some enzymes act with the assistance of nonprotein components called
a what?
– e.g. Fe, Mn, Mg etc
cofactor
T/F Many coenzymes are derived from lipids
FALSE, they are derived from VITAMINS
Do Enzymes function in a narrow or large range of environmental factors?
narrow range
What 4 factors affect enzyme activity?
▪ Temperature
▪ pH
▪ Substrate concentration
▪ Inhibitors
What do High temperature and extreme pH do to proteins?
Denature proteins
If the concentration of substrate is _________ (high or low)
saturation, the enzyme catalyzes at
its maximum rate
If the concentration of
substrate is high (saturation), the
enzyme catalyzes at its maximum rate
T/F Enzyme activity is most active b/w pH of 6-8
FALSE, pH 7-9
T or F
All active sites have bound substrate. No free active sites
True
What are competitive inhibitors?
fill the active site of an enzyme and compete with the substrate
Which type of reactions generally follow allosteric inhibition?
Anabolic reactions
If a competitive inhibitor fills the active site of an enzyme what happens?
Rxn is blocked b/c inhibitor cannot become a product
Allosteric inhibition indirectly changes what?
the shape of the active site
___________: removal of electron
___________: gaining of electrons
___________: oxidation rxn paired with reduction rxn
Oxidation: removal of electron
Reduction: gaining of electrons
Redox: oxidation rxn paired with reduction rxn
OILRIG
Mechanism for turning off the
reactions in a biosynthetic pathway
Feedback inhibition (allosteric regulation)
In biological, what are removed at the same time; equivalent to
a hydrogen atom?
Electrons and Protons
feedback/allosteric inhibition usually acts on the _____ enzyme in a metabolic pathway
first
Biological oxidations are often _____________________
dehydrogenations
In terms of electron carriers, reduced forms represent reducing power (more energy at a later time) due to what?
usable energy in bonds
What type of reactions are NADH and FADH2 used in? NADPH?
Catabolic reactions (NADH, FADH2)
Anabolic reactions (NADPH)
- Nicotinamide adenine dinucleotide (NAD+) carries how many protons and electrons?
- Flavin adenine dinucleotide (FAD+) carries how many electrons and protons?
- Nicotinamide adenine dinucleotide phosphate (NADP+) carries how many protons and electrons?
- 2 electrons and 1 proton
- 2 electrons and 2 protons
- 2 electrons and 1 proton
Energy released during oxidation-reduction reactions is trapped within the cell by what?
the formation of reducing
power (NADH, FADH2, NADPH)
What are the two general processes of carbohydrate utilization?
– Cellular respiration
– Fermentation
The addition of a phosphate to a chemical compound is called what?
Phosphorylation
- which pathway is common in respiration and fermentation?
- what two things are present in both aerobic and anaerobic respiration but absent in fermentation?
- which is the most energy efficient pathway?
- glycolysis
- Acetyl CoA and Krebs cycle
- Aerobic respiration
In cellular respiration, where does the final electron acceptor come from and is it organic or inorganic?
Comes from outside of the cell, inorganic
what is the order of Aerobic and
Anaerobic Respiration? (TCA cycle, Glycolysis, Electron transport chain, Transition step)
1.Glycolysis
2.Transition Step
3.TCA cycle (Krebs Cycle)
4.Electron Transport Chain
how many ATP are used, how many are produced? NADH? and what is the net gain in glycolysis? how many pyruvates produced?
2 ATP used
4 ATP produced
2 NADH produced
2 ATP net gain
2 pyruvate produced
How is ATP generated in glycolysis?
oxidative phosphorylation
What is another term for glycolysis?
Embden-Meyerhof pathway
which step links Glycolysis to Tricarboxylic Acid Cycle?
Modifies (3-C) pyruvate from glycolysis to (2-C) what?
Pyruvic acid is __________ and decarboxylated
- The transition step
- Acetyl CoA
- oxidized
Yield from transition step?
1. Byproduct?
- Reducing power?
- Precursor metabolites?
- CO2
- NADH
- Acetyl CoA
What are the TCA/Krebs Cycle reactants and products?
2 Acetyl CoA (reactant)
Products:
4 CO2 ( decarboxylation)
6 NADH
> Oxidation-reduction
2 FADH2
2 ATP
the term for the process wherein ATP is
generated from ADP using the energy derived from the electron
transport chain?
chemiosmosis
energy released from oxidation to reduction in oxidative phosphorylation is used to generate what in the electron transport chain?
ATP by chemiosmosis
which of the three mechanisms (phosphorylation) occurs in the electron transport chain?
oxidative phosphorylation
What are the 3 types of carrier molecules in the ETC?
flavoproteins, cytochromes, and ubiquinones
Every time electrons are being transferred in The ETC, their energy is used to do what?
Pump protons out
For aerobic respiration, the final electron acceptor in the electron transport chain is what? How many ATP does it produce?
Molecular oxygen (O2)
38 ATP (most efficient)
ATP synthase harvests energy from ________________ to synthesize ATP
Proton motive force
T or F anaerobic respiration is more energy efficient than aerobic respiration
False, aerobic respiration is the most efficient (produces 38 ATP). Anaerobic respiration is less efficient.
Eukaryotic cells have theoretical maximum of _______ ATP
\_\_\_\_\_\_ATP spent crossing mitochondrial membrane
36 ATP
- 2 spent crossing mitchondrial membrane
In ATP Synthases how many ATP is formed from the entry of 3 protons?
One NADH (10 protons) produces how many molecules of ATP?
One FADH2 ( 6 protons) produces how many moleculees of atp?
ONE ATP
3 molecules of ATP
2 molecules of ATP
ATP Yield During Prokaryotic Aerobic Respiration of One Glucose Molecule
10 NADPH = ________ ATP
+
2 FADH2 = ___________ ATP
+
2 + 2
= TOTAL ATP
10 NADPH = 30 ATP
+
2 FADH2 = 4 ATP
+
2 + 2
= 38 TOTAL ATP prokaryotic cells
T/F The final electron acceptor in the electron transport chain
is O2
FALSE, it is not O2
which 2 pathways does carbohydrate catabolism take place in the cytoplasm: in both eukaryotes and prokaryotes?
glycolysis
intermediate step
Define fermentation
Releases energy from the oxidation of organic molecules
where does carbohydrate catabolism take place for eukaryotes and prokaryotes in the Krebs cycle?
eukaryote: mitochondrial matrix
prokaryote: cytoplasm
Does fermentation require oxygen?
NO
What is the final electron acceptor in fermentation?
An organic molecule (pyruvate or a derivative)
photophosphorylation occurs only what type of cells and provide an example?
photosynthetic cells with light-trapping pigments
e.g.: chlorophylls
Types of Fermentation
- Lactic acid fermentation
- alcohol fermentation
What are the 2 additional pathways of glycolysis and what is a key component that they BOTH produce?
- Pentose phosphate pathway
- Entner-Doudoroff pathway
NADPH
In photophosphorylation, ATP is generated with the energy released from the oxidation of what?
chlorophyll
what pathway consumes ATP, reducing power and precursor metabolites?
anabolic pathways
T or F: Each chemical reaction requires use of an enzyme in order to occur fast enough
True
which is catabolic and which is anabolic:
photosynthesis and respiration?
respiration is catabolic
photosynthesis is anabolic
Which is more commonly used anabolism and catabolism between NADH and NADPH?
NADH - catabolism
NADPH - anabolism
Light independent reactions take _____ and reducing power to
make ________ compounds
Light independent reactions are also known as what?
T/F Uses energy from light reactions to produce organic
compounds (breaks down ATP)
ATP; Organic
dark rxns or calvin cycle
TRUE
How many ATP is used in dark rxns to make one sugar molecule?
54
