21: The Generation of Biochemical Energy
- Page ID
- 86320
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- 21.1: Energy, Life, and Biochemical Reactions
- This page explains that life needs energy for essential functions, with plants harnessing sunlight for glucose production and animals deriving energy by consuming other organisms. Metabolism, involving catabolic and anabolic reactions, occurs within cells. Animals primarily obtain energy from carbohydrates and lipids via respiration, which generates ATP and heat. Effective energy utilization and conservation are crucial for sustaining cellular processes.
- 21.2: Cells and Their Structure
- This page explains the two types of cells: prokaryotic, which are simple and lack a nucleus, and eukaryotic, which are more complex with a nucleus and organelles. It highlights the role of mitochondria as the cell's energy factories that produce ATP through cellular respiration, detailing their structure and function in energy metabolism.
- 21.3: An Overview of Metabolism and Energy Production
- This page explains metabolism, differentiating between anabolic (energy-consuming) and catabolic (energy-releasing) pathways. It describes a three-stage catabolism model: Stage I involves the digestion of macromolecules into monomers; Stage II breaks these down into Acetyl-coenzyme A, vital for ATP production in Stage III. The role of enzymes as catalysts in facilitating both types of biochemical reactions is also emphasized.
- 21.4: Strategies of Metabolism - ATP and Energy Transfer
- This page explains ATP's essential function as the main energy currency in living organisms. ATP comprises adenine, ribose, and three phosphate groups, releasing energy upon hydrolysis to ADP and Pi. The energy release, about 7 kcal/mol, occurs due to reduced electron repulsion among phosphate groups. ATP synthesis is energy-dependent and is integral to numerous biological processes, with its hydrolysis enabling the phosphorylation of other compounds, thus playing a vital role in metabolism.
- 21.5: Strategies of Metabolism - Metabolic Pathways and Coupled Reactions
- This page discusses the process of creating maps for LibreTexts, highlighting the importance of sharing progress instead of waiting for complete materials. It acknowledges that the current map is incomplete and some pages are still needed, but emphasizes the value of ongoing efforts to enhance it.
- 21.6: Strategies of Metabolism- Oxidized and Reduced Coenzymes
- This page explains the approach to developing educational maps, advocating for the release of incomplete maps with available content instead of delaying for completeness. It highlights that while some pages are still not available, the project is under active development.
- 21.7: The Citric Acid Cycle
- This page details the citric acid cycle, or Krebs cycle, which oxidizes acetyl-CoA to generate ATP, NADH, FADH2, and metabolic intermediates. The cycle starts with the formation of citrate from acetyl-CoA and oxaloacetate, encompassing key processes like isomerization, oxidative decarboxylation, and substrate-level phosphorylation within the mitochondria. It effectively regenerates oxaloacetate, facilitating ongoing energy production through carbon compound transformations.
- 21.8: The Electron-Transport Chain and ATP Production
- This page explains the electron transport chain (ETC), the final stage of aerobic respiration in mitochondria. It describes how energy from NADH and FADH2 is used to generate ATP through an electrochemical gradient of hydrogen ions, with oxygen acting as the final electron acceptor to form water. This process allows for the conversion of one glucose molecule into about 38 ATP, highlighting the efficiency of aerobic respiration over anaerobic methods for supporting cellular functions.
Thumbnail: Ball-and-stick model of adenosine triphosphate (ATP) based on x-ray diffraction data. (Public Domain; Ben Mills).