The reactions of energy extraction and energy use are called
metabolism or intermediary metabolism
metabolism or secondary metabolism
metabolism or globulary metabolism
Basic principles govern energy manipulations in all cells
Molecules are degraded or synthesized stepwise in a series of reactions termed metabolic pathways.
ATP is the energy currency of life.
ATP can be formed by the reduction of carbon fuels.
Although many reactions occur inside a cell, there are a limited number of reaction types involving particular intermediates that are common to all metabolic pathways.
Metabolic pathways are highly regulated
Energy is required to power muscle contraction and cell movement, active transport, and biosynthesis.
Metabolism consists of energy yielding and energy requiring reaction
Phototrops obtain energy by
capturing sunlight
the oxidation of carbon fuels
the reduction of carbon fuels
Chemotrophs obtain energy through
oxidation of carbon fuels
reduction of carbon fuels
Metabolic pathways can be divided into 3 types
Catabolic pathways
combust carbon fuels to synthesize ATP
use ATP and reducing power to synthesize large biomolecules.
Anabolic pathways use
ATP and reducing power to synthesize large biomolecules.
carbon fuels to synthesize ATP
Some pathways, called amphibolic amphillic( amphibolic, amphillic ) pathways, can function anabolically or catabolically.
Although anabolic and catabolic pathways may have reactions in common, the regulated, irreversible reactions are always distinct.
Glucose is metabolized to pyruvate in 10 linked reactions. Under anaerobic conditions, pyruvate is
is metabolized to lactate and, under aerobic conditions, to acetyl CoA.
is metabolized to lactate and, under aerobic conditions, to acetyl Cox.
The glucose-derived carbons of acetyl CoA are subsequently oxidized reduced( oxidized, reduced ) to CO2.
Energy derived from fuels or light is converted into adenosine triphosphate (ATP), the cellular energy currency.
ATP hydrolysis is
exergonic because the triphosphate unit contains two phosphoanhydride bonds that are unstable
endergonic because the triphosphate unit contains two phosphoanhydride bonds that are unstable
is used to power a host of cellular functions.
Enzymes can catalyze the transfer of a terminal phosphoryl group from one nucleotide to another
Phosphoryl Phosphatase( Phosphoryl, Phosphatase ) Transfer potential is an important form of cellular energy transformation
ATP has a ❌ potential intermediate between high phosphoryl- potential compounds derived from fuel molecules and acceptor molecules that require the addition of a phosphoryl group for cellular needs.
What phosphate serves as an energy reserve in vertebrate muscle
Creatine
ATP
ADP
ATP must never be recycled to provide energy to power the cell
Oxidation reactions involve of electrons
Oxidation reactions involve loss of electrons. Such reactions must be coupled with reactions that gain electrons. The paired reactions are called
oxidation-reduction reactions or redox reactions.
deoxidation-reduction reactions or redox reactions
The carbon atoms in fuels are oxidized to yield CO2 H2O( CO2, H2O ), and the electrons are ultimately accepted by oxygen to form H2O CO2( H2O, CO2 ).
The more reduced a carbon atom is, the more free energy is released upon oxidation.
Fats are a less efficient food source than glucose because fats are more reduced.
Compounds with high phosphoryl phosphtase( phosphoryl, phosphtase ) transfer potential can couple carbon oxidation reduction( oxidation, reduction ) to ATP synthesis
The essence of catabolism is capturing the energy of carbon oxidation as ATP.
Reduction of the carbon atom may form a compound with low phosphoryl-transfer potential that can then be used to synthesize ADP.
Ion gradients across membranes provide an important form of cellular energy that can be coupled to ATP synthesis
Ion gradients can couple endergonic reactions with exergonic reactions.
In animals, 90% of ATP is generated when
the energy of a proton gradient is coupled with ATP synthesis in the process of oxidative phosphorylation.
the energy of a proton gradient is coupled with ADP synthesis in the process of oxidative phosphorylation.
the energy of a proton gradient is coupled with ATP synthesis in the process of reductive phosphorylation.
The generation of energy from food occurs in three stages
Large molecules in food are broken down into smaller molecules in the process of digestion.
The many small molecules are processed into key molecules of metabolism, most notably acetyl CoA.
ATP is produced from the complete oxidation of the acetyl component of acetyl CoA.
None of the above
Activated carrier
ATP is an activated carrier of phosphoryl groups
Derived from vitamins
Derived from minerals
NADH/NAD+ and FADH2/FAD are activated carriers of electrons for fuel oxidation
2. Two characteristics are common to activated carriers:
The carriers are kinetically stable in the absence of specific catalysts.
The carriers are kinetically stable in the presence of specific catalysts.
The metabolism of activated groups is accomplished with a small number of carriers
The metabolism of activated groups is accomplished with a large number of carriers
Many Activated carriers are derived from vitamin, B vitamins function as coenzymes, what other vitamins play a roles but do not serve as conenzymes
Vitamins A, C, D, E, and K
Vitamins A, C, D, E,
Vitamins A, C, D
4. Key Reactions are reiterated throughout metabolism
oxidation reduction
ligation
isomeration
Group transfer
Hydroltic reaction
Reactions in which carbon bonds are cleaved by means other than hydrolysis or oxidation. In these reactions, two substrates yield one product or vice versa
Metabolic processes are regulated in three principal ways
Metabolic pathways must be regulated
create homeostasis or a stable biochemical environment.
allosterically or by covalent modification.
To maintain homeostasis, the levels of available nutrients must be constantly monitored and metabolism adjusted to meet the biochemical needs of the cell.
Homeostasis is maintained by three crucial regulatory strategies.
The quantity of enzyme present can be regulated at the level of gene transcription.
Catalytic activity
is regulated allosterically or by covalent modification
Hormones coordinate metabolic activity, often by instigating the covalent modification of allosteric enzymes.
Hormones coordinate metabolic activity, often by instigating the covalent modification of steric enzymes.
The energy status of the cell is often an important regulator of enzyme activity
Two common means are used to assess energy status: energy charge available nutrients( energy charge, available nutrients ) and phosphorylation kinetic( phosphorylation, kinetic ) potential.
Opposing reactions, such as fatty acid synthesis and degradation, may occur in different cellular compartments.
Controlling the flux of substrates between compartments is used to regulate metabolism.
