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Foundations of metabolism Flashcards
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Foundations of metabolism Flashcards
LQB481 W2 Foundations of metabolism.pdf Flashcards
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1
Question
What is required by organisms to maintain their function?
Answer
Energy, largely stored in ATP, heat, raw materials (mainly carbon), and reducing power from NADH and FADH2 / NADPH.
2
Question
How do phototrophs acquire energy?
Answer
Phototrophs transform light energy into chemical energy.
3
Question
How do chemotrophs obtain energy?
Answer
Chemotrophs obtain chemical energy through oxidation of organic compounds generated by phototrophs.
4
Question
What is metabolism composed of?
Answer
Metabolism is composed of a network of many coupled interconnecting reactions that are regulated by the action of enzymes.
5
Question
What are metabolites?
Answer
Metabolites are the reactants, intermediates, and products of metabolic reactions that are constantly shared and shuttled between different pathways.
6
Question
Why do we examine a single metabolic pathway in isolation?
Answer
To simplify and reduce the complexity of metabolic pathways.
7
Question
What is the basis for delineating specific metabolic pathways?
Answer
The way specific pathways are delineated can be somewhat arbitrary and is often based on tradition rather than chemical logic.
8
Question
What are catabolic pathways?
Answer
Catabolic pathways are metabolic pathways that degrade food molecules, often complex substances, into smaller molecules, gaining useful energy in the process.
9
Question
What are anabolic pathways?
Answer
Anabolic pathways use small molecules and energy created by catabolic degradation to synthesize new complex molecules that form the cells.
10
Question
What is the significance of oxidation-reduction reactions in cellular energy?
Answer
The oxidation of carbon fuels to CO2 represents the most important source of cellular energy, generating ATP as the major energy currency.
11
Question
What role do carrier molecules play in catabolic pathways?
Answer
Energy released during the oxidative breakdown of nutrients is stored in carrier molecules such as ATP and electron carriers like NADPH.
12
Question
What are activated carrier molecules?
Answer
Activated carrier molecules are transporters and donors of energy, electrons, and/or chemical groups in enzymatic reactions.
13
Question
What are examples of high energy carriers?
Answer
High energy carriers include ATP and coenzyme A.
14
Question
What are examples of electron carriers?
Answer
Electron carriers include NADP, NADPH, and FAD/FADH2.
15
Question
What is adenosine triphosphate (ATP)?
Answer
ATP is the universal currency of energy in all cells, releasing energy upon dephosphorylation.
16
Question
What processes utilize ATP?
Answer
ATP is used in cellular processes such as muscle contraction, active transport, signal amplification, and biosynthesis.
17
Question
How is ATP generated?
Answer
ATP is generated by the oxidation of fuel molecules like glucose, fatty acids, and amino acids.
18
Question
What is the significance of anaerobic conditions for ATP generation?
Answer
Anaerobic conditions (absence of oxygen) allow ATP generation in the cytoplasm, primarily using glucose.
19
Question
What are energy-rich phosphate compounds involved in?
Answer
They are involved in the flow of energy through metabolic processes, not just ATP.
20
Question
Give examples of energy-rich phosphate compounds created in exergonic reactions in the glycolysis pathway.
Answer
Phosphoenolpyruvate and 1,3-bisphosphoglycerate.
21
Question
What process refers to the transfer of high energy phosphate to ADP to form ATP?
Answer
Substrate-level phosphorylation.
22
Question
What must the energy in energy-rich phosphate compounds be in comparison to ATP dephosphorylation to enable ATP formation?
Answer
Higher than G -315 kJ mol^-1.
23
Question
What are low energy phosphate compounds created through?
Answer
Phosphate transfer from ATP.
24
Question
What catalyzes the transfer of energy-rich phosphate groups?
Answer
Enzymes named kinases.
25
Question
What role does phosphocreatine serve in cells, especially in skeletal muscle?
Answer
It acts as a rapidly mobilizable high energy reservoir.
26
Question
Which enzyme is responsible for the reversible phosphorylation of creatine?
Answer
Creatine kinase.
27
Question
What happens to ATP levels during periods of high demand in skeletal muscle cells?
Answer
Phosphocreatine donates a phosphate to ADP to regenerate ATP.
28
Question
What is creatinine, and how is it related to muscle creatine?
Answer
Creatinine is a breakdown product of muscle creatine and is excreted by the body at a constant rate.
29
Question
What is the importance of serum creatinine?
Answer
It is used as a diagnostic marker for renal function.
30
Question
What type of compounds are thioesters, and what is their significance in metabolic pathways?
Answer
Thioesters are high energy compounds important for metabolic pathways.