Name: how triglycerides fuel atp production
Uploaded: 2023-04-30T10:41:29.000Z
Duration: 1 min 6 s
Channel: JoVE

Yağ asitleri - yağların yapı taşları, uzun vadeli bir enerji rezervi olan trigliseritler olarak depolanır.
Bitkilerde trigliseritler kloroplast içinde üretilir ve depolanır. Bitki tohumları, embriyoya çimlenene kadar besin sağlamak için özellikle trigliseritler açısından zengindir.
Hayvanlarda, adiposit adı verilen özel hücrelerin sitoplazmasında lipit damlacıkları olarak depolanırlar.
Besin sınırlaması sırasında, lipoliz trigliseritleri yağ asitlerine ve gliserole ayırır.
Elde edilen yağ asitleri daha sonra asetil koenzim A üretmek için β-oksidasyon ile oksitlenir ve daha sonra ATP üretmek için oksitlenir.
β-oksidasyonun sadece peroksizomlarda meydana geldiği bitkilerin aksine, hayvanlarda hem mitokondride hem de peroksizomlarda meydana gelebilir.
Yağlar, glikojen gibi şekerden daha iyi enerji rezervuarları olarak işlev görür, çünkü bir gram yağın oksidasyonu, bir gram glikojenin enerjisinin yaklaşık iki katını açığa çıkarır.

enerji depolama molekülleri olarak yağlar

Fats as Energy Storage Molecules

Trigliseritler uzun vadeli enerji depolama moleküllerinin bir şeklidir. Gliserol ve üç yağ asidinden oluşurlar. Yağdan enerji elde etmek için trigliseritlerin öncelikle hidroliz yoluyla iki ana bileşeni olan yağ asitleri ve gliserole parçalanması gerekir. Lipoliz adı verilen bu işlem sitoplazmada gerçekleşir. Ortaya çıkan yağ asitleri β-oksidasyon yoluyla Krebs döngüsü tarafından kullanılan asetil-CoA'ya oksitlenir. Lipoliz sonrasında trigliseritlerden salınan gliserol doğrudan DHAP olarak glikoliz yoluna girer. Bir trigliserit molekülü, her birinde 16 veya daha fazla karbon bulunan üç yağ asidi molekülü ürettiğinden, yağ molekülleri karbonhidratlardan daha fazla enerji üretir ve insan vücudu için önemli bir enerji kaynağıdır. Trigliseritler, karbonhidratlar ve proteinlerle karşılaştırıldığında birim kütle başına iki kattan fazla enerji üretir. Bu nedenle, glikoz seviyeleri düşük olduğunda trigliseritler asetil-CoA moleküllerine dönüştürülebilir ve aerobik solunum yoluyla ATP üretmek için kullanılabilir. Yağ asidi oksidasyonu veya beta (β)-oksidasyonu olarak adlandırılan yağ asitlerinin parçalanması, yağ asitlerinin yağ asil-CoA moleküllerine dönüştürüldüğü sitoplazmada başlar. Bu yağlı asil-CoA, karnitin ile birleşerek yağlı asilkarnitin molekülünü oluşturur ve bu molekül, yağ asidinin mitokondriyal membran boyunca taşınmasına yardımcı olur. Yağlı asilkarnitin molekülü, mitokondriyal matrisin içine girdikten sonra tekrar yağlı asil-CoA'ya ve ardından asetil-CoA'ya dönüştürülür. Yeni oluşan asetil-CoA, indirgenmiş koenzimler üretmek için Krebs döngüsüne girer ve bunlar daha sonra elektron taşıma zincirinde ATP üretmek için kullanılır. Bu metin <a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/24-3-lipid-metabolism">Openstax, Biology 2e, Bölüm 24.3:</a><a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/24-3-lipid-metabolism">Lipid metabolizması</a>

Enerji Depolama Molekülleri Olarak Yağlar

Trigliseritler, uzun süreli enerji depolama moleküllerinin bir şeklidir. Gliserol ve üç yağ asidinden yapılırlar. Yağdan enerji elde etmek için trigliseritler ...

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JoVE Core

Cell Biology

Hücre Biyolojisi

Unit 1

Ünite 1

Introduction to Metabolism

Metabolizmeye Giriş

KEY TERMS AND CONCEPTS

TEMEL TERİMLER VE KAVRAMLAR

how triglycerides fuel atp production

Triglycerides store long-term energy in fats. A triglyceride is built from glycerol and three fatty acids. When the body needs energy, these molecules are broken down first.

This breakdown is called lipolysis, and it happens in the cytoplasm by hydrolysis. Lipolysis splits triglycerides into fatty acids and glycerol. The glycerol then enters glycolysis as DHAP, which connects fat breakdown to the cell’s main energy pathway.

The fatty acids are then oxidized by beta-oxidation into acetyl-CoA. Before they can cross into the mitochondrion, the fatty acids are changed into fatty acyl-CoA. They then bind to carnitine to form fatty acylcarnitine, which helps move them across the mitochondrial membrane. Inside the mitochondrial matrix, they are converted back to fatty acyl-CoA and then to acetyl-CoA.

Acetyl-CoA enters the Krebs cycle and helps produce reduced coenzymes. These coenzymes feed the electron transport chain, where ATP is made through aerobic respiration. Because one triglyceride can release three fatty acids with 16 or more carbons each, fats provide more than twice the energy per unit mass than carbohydrates and proteins. That is why triglycerides are a major energy source when glucose levels are low.

How Triglycerides Fuel ATP Production

overview of metabolism

Metabolism in Plants, Animals, and Microbes

Metabolism is the set of chemical reactions that keep living cells working. These reactions are linked through many pathways. Together, they support the normal function of cells in plants, animals, and microbes. In plants, sunlight is the main energy source. Chlorophyll pigments in the leaves absorb this light. The plant then uses that energy for photosynthesis. During photosynthesis, water is oxidized to oxygen and carbon dioxide is reduced to glucose. Glucose then serves as a starting...

carbohydrate metabolism

Carbohydrates, Digestion, and Blood Sugar

Carbohydrates are an important source of energy and a key part of human nutrition. They are made of carbon, hydrogen, and oxygen. One gram of carbohydrate provides four kilo-calories of energy, so carbohydrates are the body’s most efficient instant fuel. Starch makes up about 60% of the carbohydrates people eat. It is broken down by amylase enzymes, but amylase cannot work in the stomach’s acidic environment. That is why starch digestion happens in the mouth and the small intestine. Simple...

glycolysis: preparatory phase

Glycolysis: Energy Investment Steps

Glycolysis begins with energy investment steps in the cytoplasm of both prokaryotic and eukaryotic cells. It is the first step in cellular metabolism, which is the complete breakdown of glucose to extract energy. In heterotrophic cells, glucose enters by secondary active transport or through GLUT proteins, which are glucose transporter proteins that help glucose diffuse into the cell. The pathway starts with one six-carbon, ring-shaped glucose molecule and ends with two three-carbon molecules...

glycolysis: pay-off phase

Glycolysis: ATP and NADH Output

The pay-off phase of glycolysis turns the two three-carbon sugar molecules into ATP, NADH, and pyruvate. By this stage, the cell has already spent two ATP molecules. The remaining reactions recover that investment and add two more ATP molecules and two high-energy NADH molecules. The sixth step oxidizes glyceraldehyde 3-phosphate, a three-carbon sugar made earlier in glycolysis. High-energy electrons are transferred to NAD+, which becomes NADH. A second phosphate group is then added to form...

fates of pyruvate

Pyruvate Pathways in Fermentation

Pyruvate is a key product of glycolysis and can follow different pathways depending on oxygen availability. During glycolysis, glucose is oxidized to pyruvate, NAD+ is reduced to NADH, and two ATP are made by substrate-level phosphorylation. In aerobic organisms, pyruvate then enters the citric acid cycle, which helps produce the reduced coenzymes NADH and FADH2. These coenzymes are later oxidized in the electron transport chain to make ATP and regenerate NAD+ and FAD. When oxygen is absent,...

role of reduced coenzymes nadh and fadh&#8322;

Electron Carriers in Cellular Energy

Electron carriers help store and move energy during nutrient breakdown. Cells can save released energy by reducing these carriers or by making ATP, the cell’s main energy molecule. These mobile electron carriers bind high-energy electrons and shuttle them between compounds in metabolic pathways. The main carriers discussed here come from the B vitamin group and are nucleotide derivatives. They include nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate, and flavin...

overview of nitrogen metabolism

Nitrogen Cycle in Soil and Plants

Nitrogen moves through soil, plants, animals, and microbes in a cycle that keeps this macronutrient available for life. It is a major part of proteins and nucleic acids, so cells need it to build both amino acids and nucleotides. In nature, nitrogen is recycled from organic compounds and stored in several forms, including ammonia, ammonium ions, nitrate, nitrite, and nitrogen gas. Many of the key steps in this cycle are carried out only by prokaryotes. The largest nitrogen pool in terrestrial...

overview of fatty acid metabolism

Fatty Acids: Energy, Membranes, and Cholesterol

Fatty acids help cells store and use energy, and they also support important cell structures. Lipids are nonpolar and hydrophobic, so they do not mix well with water. Major lipid types include fats and oils, waxes, phospholipids, and steroids. Cells break down fatty acids by beta-oxidation. This process happens in the matrix of the mitochondria and cuts fatty acid chains into two-carbon acetyl groups. CoA picks up these groups to form acetyl CoA, which then enters the citric acid cycle. Extra...

sugars as energy storage molecules

Glucose Storage in Plants and Animals

Glucose storage in plants and animals helps cells manage energy for metabolism. Sugar is a simple carbohydrate, and cells use it because a lot of energy is stored in its bonds. Consumed carbohydrates often come from photosynthesizing organisms, especially plants. Plants make glucose during photosynthesis by using sunlight to convert carbon dioxide into sugar molecules. Because this builds a larger, energy-storing molecule, the process needs an energy input. Glucose can then be stored for later...

fats as energy storage molecules

Triglycerides store long-term energy in fats. A triglyceride is built from glycerol and three fatty acids. When the body needs energy, these molecules are broken down first. This breakdown is called lipolysis, and it happens in the cytoplasm by hydrolysis. Lipolysis splits triglycerides into fatty acids and glycerol. The glycerol then enters glycolysis as DHAP, which connects fat breakdown to the cell’s main energy pathway. The fatty acids are then oxidized by beta-oxidation into acetyl-CoA.

regulation of metabolism

How Cells Control Metabolic Enzymes

Cells control metabolic enzymes to match changing needs and conditions. Different cells use different enzymes and energy levels, and those needs can also change within the same cell over time. Stomach cells, fat storage cells, skin cells, blood cells, and nerve cells do not all need the same metabolic activity. A digestive cell also works harder soon after a meal than it does many hours later. As cell needs change, the amount and activity of enzymes change too. Enzymes lower activation energy,...

positive and negative feedback loops

Homeostasis and Body Feedback Control

Homeostasis keeps body conditions in a steady range through feedback control. Animal organs and organ systems constantly adjust to internal and external changes. This balance is called a dynamic equilibrium because the body keeps adapting while still staying within specific ranges. The goal of homeostasis is to stay near a set point, which is the value the body tries to maintain. A change in the internal or external environment is a stimulus. A receptor detects that change and sends a signal...

key terms and concepts

Learn how triglycerides are broken down into fatty acids and glycerol, then used to make acetyl-CoA and ATP when glucose is low.

How Triglycerides Fuel ATP Production | JoVE K12

cell biology

JoVE Core Hücre Biyolojisi, anlaşılması kolay ancak kapsamlı animasyonlu video derslerde karmaşık hücresel süreçleri gösterir. Bu koleksiyon, organeller ve zarlar, hücresel taşıma ve hücre enerjileri dahil olmak üzere hücrelerin temel bileşenlerine ve işlevlerine odaklanır. Gerçek dünya araştırma deneylerinde hücre biyolojisinin uygulanmasını gösteren bilim insanı eylem videoları ile tamamlanmaktadır.

How Triglycerides Fuel ATP Production

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